spreadsheet

Spreadsheet

Live app: spreadsheet.puter.com

An open-source alternative to Microsoft Excel: a fast, private spreadsheet app built with vanilla JavaScript (no frameworks), Vite, and Puter.js as the only backend. Files are real .xlsx documents saved to your own Puter cloud, so they open in Excel, Numbers, or LibreOffice and never live on anyone else's server.

Nobody has to sign in to work: the app opens straight into a new sheet, and Puter asks for a sign-in at the first action that needs the cloud, such as saving, opening a file, or the spreadsheet list (#/home, behind the back arrow). Until then the edits stay in the tab (and in this browser's local draft) and the status pill reads "Sign in to save".

App identity

icon.png is the source for the UI logo and browser/install icons. The primary brand color is forest green (#356d49), sampled from the icon, with lighter green accents for dark mode. The install metadata lives in public/manifest.json.

After replacing the source icon, run npm run icons (requires ImageMagick) to regenerate the PNG/ICO favicons, Apple touch icon, and standard/maskable install icons.

Features

• Formulas with live recalculation: over 510 functions covering math and statistics (SUM, AVERAGE, MEDIAN, STDEV, ROUND, SUMPRODUCT, LARGE, RANK, PERCENTILE, MODE, CORREL, SLOPE, FORECAST, SUBTOTAL, SKEW, KURT, TRIMMEAN, FREQUENCY, TREND, GROWTH, LINEST, AGGREGATE, MODE.MULT, trigonometry), distributions (NORM.DIST, NORM.INV, BINOM.DIST, POISSON.DIST, EXPON.DIST, T.DIST, T.TEST, CHISQ.DIST, CHISQ.TEST, F.DIST, F.INV, F.TEST, GAMMA.DIST, GAMMA.INV, BETA.DIST, BINOM.INV, HYPGEOM.DIST, NEGBINOM.DIST, WEIBULL.DIST, CONFIDENCE.NORM, PROB, PERCENTRANK.EXC, MARGINOFERROR), conditionals (SUMIF, SUMIFS, COUNTIF, COUNTIFS, AVERAGEIF, AVERAGEIFS, MAXIFS), database functions over a criteria table (DSUM, DAVERAGE, DCOUNT, DGET, DMAX, ...), logic (IF, IFS, AND, OR, IFERROR, SWITCH), text (CONCAT, TEXTJOIN, LEFT, MID, SUBSTITUTE, TEXT, TEXTBEFORE, REGEXMATCH, REGEXEXTRACT, REGEXREPLACE, ARRAYTOTEXT, ENCODEURL), lookup (VLOOKUP, HLOOKUP, XLOOKUP with match and search modes, XMATCH, LOOKUP, INDEX, MATCH, INDIRECT, OFFSET), dates (TODAY, DATE, EDATE, EOMONTH, WEEKDAY, DATEDIF, NETWORKDAYS, NETWORKDAYS.INTL, WORKDAY, WORKDAY.INTL, WEEKNUM, YEARFRAC, EPOCHTODATE), finance (PMT, IPMT, CUMIPMT, CUMPRINC, FV, PV, NPER, RATE, NPV, IRR, MIRR, XIRR, SLN, DDB, DB, VDB, RRI, PDURATION), math and engineering (CEILING.MATH, FLOOR.MATH, MMULT, MINVERSE, MDETERM, BASE, DECIMAL, DEC2BIN, HEX2DEC, BITAND, ROMAN, ARABIC, CONVERT with unit prefixes, ERF, ERFC, the Bessel functions BESSELJ, BESSELY, BESSELI, and BESSELK, and complex numbers with COMPLEX, IMSUM, IMPRODUCT, IMDIV, IMPOWER, IMABS, IMEXP, IMLN, IMCOSH, IMSEC, ...), discount securities and Treasury bills (DISC, INTRATE, RECEIVED, PRICEDISC, YIELDDISC, TBILLEQ, TBILLPRICE, TBILLYIELD), coupon bonds (PRICE, YIELD, DURATION, MDURATION, ACCRINT, ACCRINTM, PRICEMAT, YIELDMAT, and the coupon dates and day counts COUPPCD, COUPNCD, COUPNUM, COUPDAYBS, COUPDAYS, COUPDAYSNC), and information (ISBLANK, ISNUMBER, ISERROR, ISFORMULA, ISREF, ISEMAIL, ISURL, ISBETWEEN, FORMULATEXT, CELL, INFO), and FILTERXML(xml, xpath) to pick values out of XML text. Array constants ({1,2;3,4}), LET and LAMBDA with MAP, REDUCE, SCAN, BYROW, BYCOL, and MAKEARRAY (a LET-bound lambda can call itself; [name] declares an optional parameter that ISOMITTED checks, LAMBDA(x, x+1)(4) calls one on the spot, and a built-in named without parentheses is passed as a function: BYROW(A1:C9, MAX)), GROUPBY and PIVOTBY summaries (=GROUPBY(A2:A99, C2:C99, SUM) groups a column and totals another, with headers, subtotals, sort order, and a filter as options; PIVOTBY crosses two fields; PERCENTOF gives shares), TRIMRANGE to drop the blank edges of a range, REGEXTEST, the operators as functions (ADD, MINUS, MULTIPLY, DIVIDE, POW, EQ, GT, ...), reference unions (=SUM((A1:A9,C1:C9,E5)) adds every cell of every area; AREAS counts them and INDEX(..., area_num) picks one), a range built from two reference expressions (=SUM(A1:INDEX(A:A, COUNTA(A:A)))), the @ implicit-intersection operator (and Excel's SINGLE) that Excel writes into saved formulas, single-value functions applied to every cell of a range (=SUM(LEN(A1:A9)), =LEN(A1:A9) spills), sheet and defined names in any script (=Übersicht!A1, =合計*2), named formulas and named functions (a defined name can hold a constant, an expression, or a LAMBDA called like a function: =Double(4)), IMAGE(url) pictures inside cells, AI(prompt, [data]) answers from Puter's AI written into the cell (#BUSY! while it thinks; one question per distinct prompt, F9 asks again), TRANSLATE(text, [from], [to]) (or GOOGLETRANSLATE) and DETECTLANGUAGE(text) through the same AI, IMPORTRANGE("Budget", "Sheet1!A1:B10") cells from another spreadsheet on your Puter drive spilled into place (#BUSY! while the file loads), IMPORTDATA(url) a CSV or TSV from the web, IMPORTHTML(url, "table", 2) a table or list from a web page, and IMPORTXML(url, "//item/title") nodes picked by XPath, spilled into place (through Puter's fetch, so most addresses work), QUERY(range, "select A, sum(C) where B > 5 group by A order by sum(C) desc limit 10 label sum(C) 'Total'") in the Sheets query language (select, where with and/or/not, contains, starts with, like, matches, is null, group by with sum/avg/count/max/min, order by, limit, offset, label, and year/month/day/upper/lower/len), imported Excel relative defined names (including previous-row and previous-column offsets) that recalculate at each calling cell and retain their native definitions on export, cross-sheet references (Budget!B4, 'Q1 Data'!A1:A9), 3D references across a run of sheets (=SUM(Jan:Dec!B5) adds B5 on every sheet from Jan to Dec, hidden ones included, and follows renamed sheets and inserted rows), whole column and row ranges, named ranges, percent literals, spreadsheet error values with plain-language explanations on hover and in the status bar (a #NAME? names the misspelled function or unknown name and suggests the closest real one — "There is no function called SUMM. Did you mean SUM?" — and a #REF! names the missing sheet), and cycle detection. Workbooks that explicitly enable iterative calculation recalculate circular formulas using their iteration limit and convergence tolerance; these settings and calculated values survive XLSX export and draft recovery. NOW() and TODAY() stay current.
• Dynamic arrays: UNIQUE, FILTER, SORT, SORTBY, SEQUENCE, RANDARRAY, TRANSPOSE, FLATTEN, SPLIT, TEXTSPLIT, CHOOSECOLS, VSTACK, HSTACK, TAKE, DROP, EXPAND, WRAPROWS, WRAPCOLS, TOCOL, TOROW, and plain range arithmetic (=A1:A5*2, =IF(B1:B9>0,"yes","no")) spill into the cells beside the formula; anything in the way shows #SPILL! until it is moved. A1# refers to everything an array formula at A1 spilled (=SUM(A1#), =SORT(A1#)), and grows and shrinks with it, down to the cell itself when a FILTER narrows to one row (saved as ANCHORARRAY(A1), the form Excel uses). Array results nest inside other functions (=SUM(FILTER(...)), =COUNTA(UNIQUE(...))) and are written to .xlsx as array formulas.
• Charts and images: column, bar, line, area, pie, donut, scatter, combo (columns with a line, which can read against its own axis on the right when the two series differ in scale), histogram (with a chosen bin count), waterfall, radar, and bubble (a third column sizes the points) charts drawn from a range with detected headers and categories (a first column of text or dates, or of numbers under a header counting up evenly such as years or steps 1, 2, 3, labels the categories rather than plotting as a line of its own, and the chart dialog's Categories setting decides it either way; or from ranges selected together over the same rows, such as Month and Total; hidden and filtered-out rows and columns are left out unless the chart's Include hidden cells option is on), stacked or 100% stacked, with optional value labels, axis titles, trendlines (linear, exponential, logarithmic, polynomial of order 2 to 6, power, or moving average, per series, with a forecast forward or back, a set intercept, and the equation and R² written on the chart, as Excel saves them in .xlsx files), error bars on scatter and bubble charts (vertical and horizontal, each on or off, by a fixed value, a percentage, standard deviations, the standard error, or per-point amounts read live from cells, with their own direction, end caps, cap width, color, width and dash, kept in .xlsx files), a color of your choice per series, marker sizes for line and scatter charts (Edit chart sets every series' at once), the legend below, above, or beside the plot, fixed axis bounds, custom tick values on a value axis (listed like pages to print, such as 1, 2, 5-8, on linear and logarithmic axes; Excel has no such setting, so .xlsx files keep its automatic ticks), horizontal and vertical gridlines, each turned on or off, smooth curves for line and area charts, and axis and value labels in the data's currency, percent, or date format (large values read as K, M, B, and T), floating over the sheet; a chart's menu duplicates it, copies it to the clipboard as a picture, or downloads it as PNG or SVG. Drag to move, drag the corner to resize, double-click to edit, download as PNG or SVG; Ctrl/Cmd+Alt+O selects the next chart, image, or text box from the keyboard (the arrow keys nudge it, Delete removes it, Ctrl/Cmd+C copies it as a picture); charts follow inserted, deleted, and reordered rows and columns and are saved in the file. Excel line, scatter, clustered and stacked bar/column, and Pareto combo charts linked to worksheet ranges, including separate chart sheets, import with their theme colors, fonts, plot layout and axes; the series keep reading live cells across sheets, including non-adjacent source ranges. Date axes preserve calendar month/year intervals and rotated labels; scatter charts preserve numeric or ordinal X coordinates. Excel charts built from line or area and scatter layers retain their outlines and labels linked to cells, including hidden helper sheets and named formulas that position labels at the latest data points. Combined stacked-area, column and scatter charts preserve each group's stacking and curves, and export as editable native Excel charts. Numeric axes preserve built-in and custom display units and their labels through Excel export. Chart data tables preserve live formatted values, fonts, border options and series keys through native export, chart duplication and copying as a picture. Compact progress charts retain their percentage scales, plot borders, and individual bar colors. Excel's single-series pie and doughnut charts retain their slice colors, borders, hole size, rotation, and live category/value labels, including custom label fields and positioning. Native bubble charts retain each series' X, Y and size vectors, including embedded chart values, gradient fills, value labels, standard error/deviation, fixed and percentage error bars, and chart-relative text annotations. Sheet default column widths keep chart anchors and the surrounding cells aligned with the imported layout. Excel's newer ChartEx Pareto charts also import with live category totals, descending bars and a cumulative percentage axis. Transparent chart fills, plain filled decorative rectangles, numeric freeform vector groups, and embedded raster pictures retain their placement; pictures keep their size, rotation and mirroring. Pictures from your device, dropped onto the sheet, or pasted from the clipboard (a screenshot, an image copied from a page) float the same way (resized keeping their proportions, replaceable). SPARKLINE(range, "line" | "column" | "bar" | "winloss") draws a mini chart inside a cell. Text boxes (Insert → Text box, or the cell menu) float over the sheet the same way for titles, notes, and captions, with a font size, bold and italic, text and fill colors, alignment, and an optional border; double-click to edit, and they print where they sit.
• Hierarchy, statistical, stock and surface charts: Insert ▸ Charts also offers treemaps and sunbursts (each leading label column is a level of the hierarchy, blank parent cells repeat the label above; parents are named overlapping their boxes, in a banner, or not at all, and each top-level branch keeps one colour), box and whisker charts (exclusive or inclusive median quartiles, whiskers to 1.5 interquartile ranges, outlier and inner points, mean markers and a mean line, rows pooled by category), funnels, stock charts (High-Low-Close, Open-High-Low-Close with up/down bars, and both with volume columns on their own axis), 3-D surface, wireframe, contour and wireframe contour charts coloured in value bands set by the value axis's major unit, and exploded pie and doughnut, pie of pie and bar of pie charts. Each has its gallery tile and Change Chart Type page, Recommended Charts suggests them for data of their shape (price columns, nested labels, long columns of numbers, stage counts), and the Format pane sets their options. They round-trip through .xlsx: treemaps, sunbursts, box and whisker and funnel charts as extended chart parts (with a fallback note for older readers, and named sources read as other apps write them), stock and surface charts as classic chart parts.
• Hyperlinks: HYPERLINK(url, label) cells and typed web or email addresses are clickable (Ctrl/Cmd+click opens them, a popover shows where they go). Ctrl/Cmd+K inserts or edits a link to a web address, to a sheet and range, or to a named range (#Sheet!A1, the form Excel uses); a place link jumps there; Remove link (in the cell menu or the link dialog) leaves the text plain, a typed address included. Links round-trip through .xlsx. Copy link to this cell (or range, in the cell menu) puts an address on the clipboard that opens the file with those cells selected, on that sheet, for pasting into a chat or a document.
• AI assistant: a chat beside the sheet, open by default (the Ask AI button, View → AI assistant, or Ctrl/Cmd+J open and close it; closed, it stays closed on the next visit) where Puter's AI (Claude Opus 5.5) answers questions about the workbook and changes it: it reads cells, works figures out with the formula engine rather than guessing, and can write values and formulas, fill a column, format, sort, insert and delete rows and columns, add charts, tables, conditional formats, dropdowns, notes and sheets, freeze panes and size columns. Each tool call shows as a step in the reply, linked to the cells it touched, and cell references in a reply select their cells. A change that replaces or deletes data waits for Allow (or every change, or none, as chosen in the panel's menu); every change is an undo step, and a reply that changed the workbook ends with an Undo for all of its changes (only while nobody has edited since). Each message is sent with a short summary of the sheets and the selected cells, which the panel names; cell contents are treated as data, never as instructions, a formula it writes that fetches from the web waits for the file's Allow, and pictures in replies are never loaded. On a phone the panel is a sheet over the grid.
• Automate (scripts): an Automate ribbon tab for JavaScript scripts with an async function main(workbook) that work on the workbook through a documented object model (worksheets, ranges, values and formulas, fills, fonts, alignment, borders, sizes, insert and delete, sort, fill, merge, hide, notes, links, tables and charts; Script Reference lists it all). The Code Editor pane beside the sheet has syntax colouring, line numbers, indentation that follows the code, closing brackets and quotes, bracket matching, Find and Replace, line comments, completions for the API, Run (Ctrl/Cmd+Enter) and Stop, and output whose errors link to their lines. Record Actions writes what you do (typing, formatting, borders, inserting and deleting, sorting, fill, sizes, sheets, tables) as a new script. All Scripts gathers the workbook's scripts, My Scripts (.js files kept on your drive, for any workbook) and samples, which also run straight from the ribbon: highlight duplicates, unhide everything, sum each column, a table of contents sheet, style the header row, remove blank rows. Script Button puts a button on the sheet that runs a script when clicked (Shift+click selects it). Everything a run changes is one undo step. Scripts run in a worker inside a sandboxed frame with an origin of its own and no network, so they reach the workbook and nothing else (not the page, your account or your files), and they are stopped after two minutes or when you press Stop; a script that came inside someone else's file runs only once you agree. Scripts are saved with the workbook, in .xlsx as a package part of their own that other programs leave alone.
• AI help with formulas: describe what a cell should calculate and Puter's AI writes the formula (the sheet's headers, a few sample rows, tables, and named ranges are explained to it, and the dialog says which cells were sent; you check it and insert it), or ask it to explain the formula in the active cell in plain language (Insert function menu and the cell menu). Ask AI about this data sends a question with the selected cells' values (or the sheet's data, up to 60 × 15) and shows the answer, which can be copied or written into a cell.
• Formula help while typing: function-name autocomplete with descriptions (named ranges and tables included, and a table's columns once Table[ is typed), a signature hint that tracks the current argument, colored reference highlights (structured references light up the table cells they name), click-to-insert references, point mode (the arrow keys pick a reference wherever the formula expects one, Shift extends it to a range), AutoSum with Alt+=, and the closing parentheses a typed formula leaves open are added on entry (=SUM(A1:A5 becomes =SUM(A1:A5)), as Google Sheets does.
• Editing the way spreadsheets are expected to work: type to replace, F2 or double-click to edit in place, Enter and Tab that walk a selection, Ctrl/Cmd+Arrow to jump across data, Shift to extend, Ctrl/Cmd+A to select the block of data around the active cell (the whole sheet on a second press), Ctrl/Cmd+Enter to fill the whole selection, Ctrl/Cmd+D and R to fill down and right, a fill handle that continues numeric series and month, weekday, and quarter names (and double-clicks to fill alongside data; Ctrl/Cmd flips it to count a lone number up or repeat a series), a Fill series dialog (linear, growth, or date steps to a stop value), copy/cut/paste with relative reference adjustment (a cut leaves its cells in place until the paste moves them, in one undo step; pasting a table copied from Excel or Google Sheets keeps its formatting, links, typed values, and number formats), paste special (values only, formatting only, formulas only keeping the target's formatting, transposed, skipping blanks, as links back to the copied cells, inserted with the cells already there shifted down or right, column widths, or add, subtract, multiply, and divide into the numbers already there), insert and delete rows and columns with every formula on every sheet updated (a new row or column takes the formatting of the one above or to its left), insert or delete cells shifting the rest down, right, up, or left (references in the shifted band follow), and 200 levels of undo — fewer when the steps hold more cells between them than the memory allowed for them, so that a run of sorts over a large table cannot fill the tab (right-click Undo or Redo for the history and step back several actions at once). Drag a selection by its border to move it (references follow the moved cells; Alt copies instead), and drag a selected row or column header to reorder rows or columns (a move that would cut through a merged block, or land on part of one, is refused). Ctrl/Cmd+click adds cells, ranges, rows, or columns to the selection: formatting, clearing, hiding, deleting rows or columns, and fitting rows or columns to their content act on all of them at once, Enter and Tab walk the active cell through each of them in turn, and the status bar sums them together; Select cells in the cell menu picks every blank, formula, typed value, number, text, error, or noted cell in the data the same way. Typed dates are recognized in the common shapes (2026-08-28, 8/28/2026, 8/28/26, 28/8/2026, 8/28, Aug 28, 2026, 28 Aug 2026, 28-Aug-26, with an optional time, and with the month written in the regional format's language as well as English: 5. März 2026, 15 mars 2023, 2023年3月15日), as are accounting negatives like (1,234), elapsed times such as 25:30 or 100:00:30, which are read as durations, and the error spellings #N/A, #DIV/0!, #VALUE!, #REF!, #NAME?, #NUM! and #NULL!, which become error values (a leading apostrophe keeps them text); in a cell already formatted as a fraction, 1/2 is the fraction one half rather than January 2, and a whole number typed into a percent cell is that many percent (5 is 5%, 0.5 is 50%). Dates are stored as day counts from 30 December 1899 without Excel's phantom 29 February 1900, as Google Sheets stores them, so serials from 1 March 1900 on match Excel's and the few before it are one day behind. Typing text suggests a matching value from the same column, selected so Enter keeps it. Date cells open a calendar on double-click or Alt+Down (Pick a date in the cell menu turns any cell into one). F4 cycles the $ anchors of the reference at the caret. Ctrl/Cmd+ shows formulas instead of values (on a Mac, Ctrl+ and Ctrl+Space also work, since ⌘+` and ⌘+Space belong to the system); Ctrl/Cmd+G goes to a cell, range, or name; Ctrl/Cmd+' copies the formula from the cell above as written, its references unshifted (Ctrl/Cmd+D fills it down with them shifted); F9 recalculates. Ctrl/Cmd+[ and ] highlight a formula's precedents and a cell's dependents (also in the cell menu) to see where numbers come from and go, and Evaluate formula (cell menu) lists every part of a formula with the value it produces, innermost first.
• Clipboard: copies go out as tab-separated text and as an HTML table that keeps bold, colors, alignment, links, and the conditional-formatting and table colors showing on screen in other apps (and formulas and styles in another tab of this app). Range copies within the app also carry live conditional-format rules, including formatting-only, transposed and repeated pastes; values-only and formulas-only leave destination rules intact. Tables pasted from Excel, Sheets, or a web page arrive with their basic styling.
• Find and replace (Ctrl/Cmd+F; Ctrl+H, or Cmd+Shift+H on a Mac): matches in displayed text and formulas, highlighted in the grid; match case, entire cell, all sheets or only the selected range (one or the other; the range is taken by itself when one is selected), regular expressions (with $1 groups in the replacement), replace one or all.
• Formatting: font family, bold, italic, underline, strikethrough, font size, horizontal and vertical alignment, indent, text rotation (tilted or vertical, rows grow to fit), text wrapping as overflow, wrap (with automatic row height), or clip, text and fill colors from a palette, a browser color picker, a hex field, or recent colors, borders (all, outer, inner, horizontal, vertical, or one side) in any color and thin, medium, thick, dashed, dotted, or double, merged cells (whole, horizontally, or vertically), a format painter, cell style presets (Title, Heading, Total, Input, Good, Bad, Neutral, Note, ...), and number formats (automatic, number, currency with a symbol picker (the yen and the won without decimals unless you add them), accounting, percent, fraction, scientific, date in three styles, time, duration, date and time, text) with adjustable decimals and a thousands separator toggle, plus custom spreadsheet format codes (#,##0.0 "kg", [h]:mm, 0.0%;[Red](0.0%)) with a live preview. A Format cells dialog (Ctrl/Cmd+Shift+F, or Ctrl+1 where the browser leaves it free) gathers number format, alignment, font, borders, and fill in one place and applies only what changed. It keeps one size on every tab; the Number tab says in a line what the chosen category does; the Border tab draws its line styles as the lines they make, with None, Outline and Inside presets and a diagram of the selection whose edges (and the buttons beside them) draw or remove a line; the Fill tab offers the theme's colours with their tints and the standard fills as palettes beside a large sample. Keyboard shortcuts (Ctrl/Cmd+Shift+1/2/3/4/5/6/~ for formats, Ctrl/Cmd+Shift+7 and _ for an outline border and no borders, Ctrl/Cmd+\ to clear formatting). Formatting more than 50,000 cells at once (Select all on a sheet of many rows) formats the cells that hold something and the empty cells up to 100 rows below and 26 columns right of them, while that block stays under 50,000 cells; the other empty cells keep the default format instead of each becoming a stored cell that every save and scan would carry. Borders over such a selection follow the same rule, except that an outline, or one named side, is drawn on the selection's own edges however many rows it spans. A format applied to a whole column or row is kept on the line itself, so it holds for the rows the sheet has not reached yet: a value typed, pasted or filled into a formatted column takes its format wherever it lands, and the column keeps it through inserted, deleted and moved lines until Clear formats takes it away.
• Cell styles: a gallery of built-in styles (Title, Heading, Total, Input, Good, Bad, Note and the rest), themed accent styles, and the workbook's own named styles. New Cell Style… makes one by example from the active cell; the Style dialog names it and chooses which parts of a format it holds (number, alignment, font, border, fill, protection), each shown with a summary, and Format… edits it in the Format Cells dialog. Applying a style changes only the parts it holds. Right-click a style (or press the menu key on it) to modify, duplicate or delete it; modifying a style reformats every cell that uses it, in one undo step, and a built-in style can be modified for one workbook and reset later. Merge Styles… copies the styles of another spreadsheet (from the Spreadsheets folder, Puter, or this device) and asks before replacing same-named ones. Named styles travel in .xlsx files as the file's own cell styles, with cells linked to them.
• Conditional formatting: highlight cells that are greater or less than, between, equal, contain, begin or end with text, are empty, are duplicates or unique, are in the top or bottom N, hold a date that is today, yesterday, in the last 7 days, this week, this month, in the past, and so on, or satisfy a custom formula (=$C2>$B2), paint a two- or three-color scale, draw data bars, mark values with an icon set (arrows, traffic lights, flags, stars, or checks at adjustable thresholds, beside or instead of the value), or band rows in alternating colors with a header (one click from the cell menu). Icon thresholds remain accurate when finite endpoints have a span larger than the numeric range, including mixed positive and negative values.
• Data validation: dropdown lists (literal values or a range, whose options read as the source cells show them, dates as dates and amounts with their symbol; shown as plain text or as colored chips with a fill of your choice per option), number ranges, text length, dates, custom formulas that see the value being typed, and checkbox cells, with strict rejection or an invalid marker, and an input message that appears beside the cell while it is selected. Insert checkbox and Insert dropdown are one click away in the cell menu.
• Tables: turn a range into a named table (Create table in the cell menu) with a styled header row, banded rows in one of seven colors, filter buttons, and an optional totals row of SUBTOTAL formulas. Formulas can use structured references the way Excel writes them: Sales[Amount], [@Qty]*[@Price] for the same row, Sales[[#Headers],[Price]], Sales[#All], Sales[[Qty]:[Price]], and the tables of an Excel file open as tables, so its structured references keep working. Legacy non-array calculated columns retain implicit row intersections in scalar calculations while aggregates keep their column ranges. Typing, pasting, or filling that reaches past a table's last row extends it, whether it starts on that row or below it (as does Tab from its last cell, or dragging the corner handle), a formula typed into an empty column fills the whole column and carries into rows added later (a calculated column) — including the empty column beside the table, which the formula draws into it — charts, conditional formats, and validation rules that end at the table's last row grow with it, renaming a table or a column header rewrites every formula that used the old name, and converting back to a range turns the references into plain cell addresses (which is also how they are written into the .xlsx for other programs, with the originals kept in the meta sheet). The name box lists tables and jumps to one (Sales, or Sales[Amount] for a column), and a chart's range or a dropdown's list source can name a table or a table column, so both keep up as it grows.
• Data tools: filters with per-column value menus, search, sort, fill color, conditions (greater than, between, contains, begins with, empty, ...), and a custom formula written for the first data row (=B2*C2>10); a multi-key Sort dialog with header detection, text in dictionary order (accented letters beside their base letters), case-sensitive ordering, sorting by fill color (rows with a color on top or at the bottom), and sorting columns left to right as well as rows; subtotals (a SUBTOTAL row under each run of a column's values and a grand total, with the detail rows grouped to collapse, removable again in one click); randomize the order of the selected rows; remove duplicate rows (choosing which columns must match) or empty rows; split text to columns on a detected or chosen separator, or with Text to Columns (Data menu and ribbon): any mix of separators with repeated ones counted once and a choice of text qualifier, or fixed widths picked on a clickable ruler, a live preview where each column is read as values, kept as typed text or skipped, and a destination cell; trim whitespace, change case, and convert text to numbers; and pivot tables that summarize a range by rows, columns, and Sum, Count, Average, Max, or Min onto a new sheet as live SUMIFS/COUNTIFS formulas (over a table, they name its columns and follow it as it grows), with an optional filter field whose value sits in a dropdown cell above the table — pick a value, or "(All)", and the whole table re-filters; Refresh (Alt+F5) or Refresh All (Ctrl+Alt+F5) builds such a pivot table again over its source as it now is, taking in categories added since; Goal seek, which finds the input value that makes a formula reach a wanted result; and Column stats, a profile of a column (counts, sum, average, median, spread, the most frequent values, and a distribution).
• Solver (Data ▸ Analyze, the Data menu, or the palette): make a formula cell as large or as small as it can be, or equal to a value, by changing variable cells (several ranges) subject to constraints (<=, =, >=, whole numbers, 0/1 and all different), with three methods: Simplex LP for linear models (a bounded two-phase simplex that cannot cycle, with a check that the model really is linear), GRG Nonlinear for smooth models (gradients measured through the sheet's own recalculation, optionally from many starting points) and Evolutionary for models built on IF, lookups or rounding; integer constraints go through branch and bound. Options cover precision, scaling, time and iteration limits, integer optimality, convergence, derivatives, population, mutation rate and a random seed. The solve runs in the background with a Stop button; the result can be kept or the original values restored, saved as a scenario, and reported on new sheets (Answer; Sensitivity with reduced costs, shadow prices and allowable ranges, or reduced gradients and Lagrange multipliers; Limits). Keeping a solution is one undo step. The model is saved with the sheet in hidden defined names, so it travels in .xlsx files, follows inserted rows and columns, and can also be saved to and loaded from a range of cells.
• Data Analysis (Data ▸ Analyze): a list of statistical tools, each with its own dialog — Anova (single factor, two-factor with and without replication), Correlation, Covariance, Descriptive Statistics (with a confidence level and kth largest and smallest), Exponential Smoothing, F-Test for variances, Fourier Analysis, Histogram (with Pareto order, cumulative percentage and a chart), Moving Average, Random Number Generation (uniform, normal, Bernoulli, binomial, Poisson, patterned and discrete, with a seed), Rank and Percentile, Regression (multiple X columns, residuals, standardized residuals, residual, line fit and normal probability plots, a chosen confidence level, constant zero), Sampling, t-Tests (paired, equal and unequal variances) and a two-sample z-Test. Inputs grouped by columns or rows with optional labels are checked with clear messages; results (and their charts) go to a range, a new sheet or a new spreadsheet as one undo step, computed with the same statistics as the sheet functions (LINEST, T.DIST, F.DIST…).
• Data form (Data → Form, or Data → Data Tools → Form): a list or table one record at a time, its header row naming the fields and calculated columns shown read-only. Step through records with the slider, the arrow keys or Page Up/Down; edits are written when you move on (one undo step per record) and Restore puts the record back; New adds a record under the list (growing a table, carrying a plain list's formulas down), Delete removes one after asking, and Criteria finds records by field (>100, <>0, =Smith, text that begins with what you type, * and ? wildcards) with Find Prev and Find Next.
• Edit links (Data → Edit links, or Data → Queries & Connections → Edit Links): every link to another workbook with its source file, kind, update mode and status. Update Values reads the source again from your Puter drive and refreshes the cached cells the formulas read; Change Source points a link at another file (picked on the drive), Open Source opens it, Check Status looks for every source (and its sheets), and Break Link turns every formula that reads a link into its current value, dropping the link and renumbering the rest, in one undo step. Startup Prompt chooses whether opening the book offers to update its links, updates them, or leaves them (kept in the .xlsx as the workbook's update-links setting).
• Layout: frozen rows and columns (from the menus, or by dragging the bars at the corner of the headers), hidden rows and columns, row and column groups with an outline gutter (collapse and expand one or all, nested, Alt+Shift+Right/Left); Auto Outline builds nested row and column groups from the summary formulas (SUM, SUBTOTAL, AVERAGE and the like beside the cells they total), Clear Outline removes them, and Outline Settings puts summary rows above or below their detail and summary columns left or right of it (saved in .xlsx files) and can set summary lines in bold automatically (Data → Outline), column and row resizing (drag, double-click to fit, or an exact size), zoom from 10% to 400% (presets from the status bar, or View ▸ Zoom with 200%, 100%, 75%, 50%, 25%, Fit selection or a percentage of your own), optional gridlines, zero values that can be hidden per sheet, notes on cells, and colored sheet tabs. The row and column headers can be hidden, a focus mode hides the toolbar and formula bar, the app can go full screen (all in the View menu), and spelling is checked while typing text (never inside formulas; Tools menu).
• Page breaks: Page Layout ▸ Breaks inserts a manual page break above and left of the selected cell (whole rows or columns break on their own axis), removes the one beside it, or resets them all, each an undo step; the cell menu offers the same in Page Break Preview, where manual breaks are solid lines and automatic ones dashed, a break drags to another row or column (an automatic one dragged becomes manual, one dragged off the print area goes), and the print area's edges drag to resize it. Printing and PDF start a new page at every manual break (fit-to-pages settings decide the axis they fit), breaks follow rows and columns as they are inserted, deleted or moved, and they are saved as the worksheet's native row and column breaks. View ▸ Page Breaks (or a print preview) shows them in Normal view as dashed lines.
• Sheet background: Page Layout ▸ Background tiles a picture behind the cells on screen (a cell's fill covers it, and it never prints); Delete Background takes it away. It is kept as the worksheet's native background picture.
• Custom Views: View ▸ Custom Views keeps the workbook's present view under a name, with or without its page setup and its hidden rows, columns and filters, and Show brings it back: each sheet's zoom, selection, scroll position, frozen panes or split, Normal, Page Layout or Page Break Preview, gridlines, headings and zeros, which sheets are hidden, and the sheet in front, with the edits among those one undo step. Views are saved in the file as native custom workbook and sheet views.
• Sheet views: View ▸ Sheet View ▸ New starts a temporary view of the sheet in which you filter for yourself while everyone else keeps the default view (the headings take a tint and the sheet tab an eye); Keep names it so it stays with the workbook, Exit goes back to the default view, the Sheet View menu switches between the sheet's views, and Options renames, duplicates or deletes them. Files and drafts always hold the default view's filters with the named views beside them, the view you are in is remembered on this device for that file, and sorting (which moves the rows themselves) still applies to everyone.
• SmartArt graphics: Insert ▸ Illustrations ▸ SmartArt opens a gallery of 37 diagram layouts in seven categories (list, process, cycle, hierarchy, relationship, matrix and pyramid: block and bullet lists, steps, chevrons, a timeline, cycles, hub and spokes, organization charts and trees, overlapping circles, a target, a balance, an equation, quadrants and pyramids), each shown drawn by the same engine that draws the diagram. A diagram is an outline: the Text Pane beside the sheet edits it as a bulleted list (Enter adds an item, Tab and Shift+Tab demote and promote it, Alt+Shift+Up/Down moves it, Backspace joins lines, several pasted lines become several items), and the layout works out every shape, connector and text size again from it, fitting like shapes to one size and following the diagram's resizing; with a range of cells selected, a new diagram takes its outline from them. The SmartArt Design tab adds shapes after, before, above or below the one picked, promotes, demotes and moves it, turns the diagram Right to Left, switches to another layout keeping the text, and offers 31 colour schemes and six styles drawn from the workbook's theme (so a new theme recolours every diagram), Reset Graphic and Convert to Shapes (a group of ordinary shapes and text boxes). The Format tab gives a shape picked in the diagram its own fill, outline and text colour, makes it larger or smaller, or changes it to another shape. Every change is one undo step (typing in one item undoes together); diagrams arrange, group, print and export to PDF like other objects, read their text out as alt text unless given their own, sync between people editing together, and are saved in an .xlsx as a group of ordinary shapes any spreadsheet program shows, with the diagram kept for this app to edit again. A diagram another program saved opens with the shapes that program drew, its outline in the Text Pane, and is redrawn with the nearest layout once changed.
• Arranging objects: charts, pictures, shapes, text boxes, WordArt, slicers, timelines and controls stack in an order of their own. Page Layout ▸ Arrange (and a chart's Format tab, and the object menu) brings them forward or to the front, sends them backward or to the back, aligns them left, centre, right, top, middle or bottom, distributes three or more evenly, groups, ungroups and regroups them (a group moves, orders and aligns as one, and is saved as a native group), and rotates or flips pictures, shapes and text boxes by quarter turns; Snap to Grid and Snap to Shape line up objects as they are dragged or resized (Alt places one freely, or with both off lines it up with the cells, as in Excel), and Shift held while dragging a corner keeps an object's proportions (while dragging the object, it moves straight across or down). Shift- or Cmd/Ctrl-click selects several objects, which then drag, nudge with the arrow keys and delete together. The Selection Pane lists every object on the sheet, front first and groups with their members, with an eye to hide or show each (Show All, Hide All), a double-click or F2 to rename one, Delete to remove those picked, and rows that drag to restack; hidden objects do not print, and names, hidden state and order travel in the .xlsx.
• Multiple sheets: add, rename, duplicate, reorder, color, hide, protect, and delete sheets from the tab bar, the Insert menu's Sheet submenu, or the palette, or copy one to another spreadsheet (a new file named after the sheet, or one already in Spreadsheets/, which gets the sheet after its own); Ctrl/Cmd+PgUp/PgDn or Alt+Up/Down (Option+Up/Down on a Mac) switch sheets, the mouse wheel scrolls the tab strip when the tabs overflow it, and a focused tab answers the arrow keys, Home and End, F2 to rename it, and Shift+F10 or the Menu key to open its menu. Renaming a sheet rewrites the references that point at it, and deleting one turns them into #REF! references (a defined name that pointed at the sheet stays listed and reads #REF!; only names scoped to the sheet go with it). A protected sheet refuses changes with a notice until it is unprotected, and protected ranges (with a description of why) do the same for a few cells on an otherwise open sheet; a row, column or block of cells inserted or moved inside such a range is refused too, as deleting one out of it is, so a protected block cannot be broken up by a line nobody may then fill (an insertion that only moves the whole range still goes through). Protecting a sheet is an undo step of its own, as the gridlines and zero-value switches are, so Ctrl/Cmd+Z after one takes back that setting and not the edit before it.
• Grouped sheets: Shift-click a sheet tab to group every sheet from the one in view to it, Ctrl-click (⌘-click on a Mac) to add or drop one sheet, or right-click a tab → Select All Sheets. The title shows [Group], and what you type, format, clear, fill or paste, the rows and columns you insert or delete, and the column widths and row heights you set land on the same cells of every grouped sheet, as one undo step (each sheet keeps its own formatting when only values are typed). Edit → Fill → Across Worksheets copies the selection to the other grouped sheets (all, contents only, or formats only); Hide and Delete act on the whole group. Commands that belong to one sheet (tables, charts, sorting, filters, conditional formatting, validation, notes, freezing) are greyed out and say why until the sheets are ungrouped, by clicking a tab outside the group or with Ungroup Sheets.
• AutoCorrect (Tools → AutoCorrect Options, or Review → Proofing): as a word ends in a cell or the formula bar (never in a formula), listed text is replaced — (c) → ©, (tm) → ™, -- → –, -> → →, and common typos such as teh → the, keeping the case it was typed in — TWo INitial CApitals and words typed with caps lock on are fixed, days get a capital, and so does the first word after a full stop (abbreviations such as e.g. and etc. are exceptions you can edit, and the first word of a cell is left as typed). Ctrl/Cmd+Z straight after a correction puts the word back; a last word corrected as the entry is committed is an undo step of its own. The list, the exceptions and an optional \alpha → α math-symbols rule are kept for your account.
• Spelling, thesaurus and translation (Review → Proofing and Language, or the Tools menu): F7 checks the text cells of the selection, or of the whole sheet from the active cell round to it, against English word lists from SCOWL (American or British, loaded the first time they are needed). Each word not in the dictionary is shown in its sentence with the nearest suggestions, to Change or Change All (one undo step), Ignore Once or Ignore All, Add to Dictionary (your own dictionary, kept for your account and editable), or add to AutoCorrect; words in capitals, words with digits and web, email and file addresses are skipped unless you say otherwise. Shift+F7 opens the Thesaurus pane on the active cell's word: its meanings with synonyms and antonyms from Puter's AI, a click to look any of them up, and Insert to put one in place of the word. The Translator pane translates typed text or the selected cells (as TRANSLATE() does) and puts the result in the active cell or back into the cells it came from, in one step.
• Templates: start from a monthly budget, an expense tracker with a donut chart, an invoice, a to-do list with checkboxes and priorities (the last three built on tables), a loan calculator with an amortization schedule, a grade book, a weekly schedule, a project timeline drawn with conditional formatting, a monthly calendar, or a habit tracker, each with live formulas and blue input cells.
• Files: every document is an .xlsx in Spreadsheets/ on your Puter drive, autosaved a moment after each change; if the file was written from elsewhere in the meantime (another device or tab), you are asked whether to overwrite it or reload theirs (a file merely renamed or moved elsewhere, its contents unchanged, is not taken for one that changed). Document details (File menu) lists the file's location, size, last save, and per-sheet counts. Open .xlsx, .xls, .csv (comma, semicolon, tab, or pipe separated, detected, or named by a leading sep=; line as Excel reads it), .tsv, and .ods files from your device (or drop one anywhere on the app, over a dialog included) or from Puter (delimited text opens with its columns fitted to the data); a file is read by its bytes, so comma-separated text saved as .xlsx opens as text and a workbook named .csv as the workbook it is, while a .csv, .tsv or .txt that is not a workbook is delimited text whatever its first cell says (ID;Preis, <table, <?xml). Import a file into the open spreadsheet — as new sheets, in place of the current sheet, appended below its rows, or starting at the selected cell; download or export as .xlsx, .ods, .csv, and .tsv (a sheet, a selection, or a table), as a web page (an .html table keeping the formatting), or save as PDF; print the sheet, a selection, or every sheet (the browser's own Print command prints the sheet too, not the app), portrait or landscape, on Letter, A4, Legal, A3, or Tabloid paper with narrow, normal, or wide margins, fit to the page width (a sheet wider than the page is scaled down, text and all, rather than cut short), at actual size, or at a chosen percentage, or fit to a chosen number of pages wide and tall. Imported XLSX print areas, paper orientation, scale, fit settings, exact margins, centering, gridlines, and header/footer text are retained in native XLSX records. The print dialog shows the pages as they will print beside its choices (paper, orientation, scale, margins, centring, breaks, gridlines, headings, title, header and footer), page by page, and follows every change. It starts with the sheet's saved page setup and offers custom margins and separate pages for nonadjacent print areas, with your own header and footer text on every page (&[Page], &[Pages], &[Date], &[Time], &[Tab], and &[File] fill in the page number and count, date, time, sheet, and file name, &L/&C/&R start the left, center, and right parts, and the footer reads "Page 1 of 3" unless you write your own), optional gridlines, row and column headers, frozen rows repeated on every page (in a printed selection too, when it starts at them), printing from the first used cell (a blank form's fills and borders count as used, though a column or row filled, or ruled with a single border side, to the sheet's edge prints only as far as the data), the pictures of IMAGE() cells, the tick boxes of checkbox cells, and charts and images placed over the cells where they sit on screen (beside or below the data too); conditional formatting and table styling print as they show on screen. The home list sorts by last modified, name, or size, searches the names without their extensions, keeps its "2 min ago" times current, and files opened from elsewhere on the drive are kept in a "Recently opened" strip on this device. Inside the Puter desktop, spreadsheets saved where you chose in Puter's Save dialog are listed with the rest, wherever they are moved. The app registers for "Open with" so double-clicking a spreadsheet opens it here.
• Regional formats: pick how numbers and dates are written and read (account menu): 1.234,50 and 28.8.2026 in German, day-first dates in British English, and so on. Typed values, the general format, custom format codes (month and weekday names included, unless a [$-407]-style locale tag in the code names another language), CSV export (;-separated where the decimal mark is a comma), NUMBERVALUE without separators of its own, FIXED and DOLLAR, and the text that VALUE or a criterion such as ">1.500" reads as a number all follow; formulas keep a period for decimals. The Currency and Accounting formats take the regional format's own currency on a cell that has none (pounds in British English, euros in German, yen in Japanese), the number-format menu's samples and Format cells' date styles show each format the way the sheet would, and an amount written the way any regional format shows it (US$1,234.50, 1 234,50 kr, 1.234,50 €, USD 1,234.50) reads back as that currency when typed, pasted or imported. A Currency cell exports and copies with its label on the side of the digits the regional format puts it (#,##0.00 € under Deutsch, "$"#,##0.00 under English (United States)), and a written-out or long date with that format's own order and language tag ([$-809]d mmm yyyy under English (United Kingdom)), so the sheet opens in Excel the way it reads here. Formulas whose results are written in the regional format (TEXT, DOLLAR, FIXED) are recalculated when it changes, as F9 recalculates them.
• Design: grouped Home, Insert, Page Layout, Formulas, Data, Review, View and Automate ribbon tabs reuse the existing commands and formatting controls. Arrow keys navigate tabs; Down enters a group, and double-clicking a tab collapses the ribbon. Overflow controls keep commands reachable in narrow windows. Unsupported ribbon features are disabled. The original menus remain available. A formula bar keeps Apply/Cancel beside the name box, and a status-bar slider changes worksheet zoom. The formula bar expands to several lines for long formulas (Alt+Enter adds a line), sheet tabs, and a status bar that sums the selection (with min and max) and explains an error in the active cell; right-click it to choose what it shows, each choice listed with its current value, the menu staying open while you switch several. Works on desktop, tablet, and phone (tap to select, tap again to edit, long-press for the menu). Light, dark, and system themes, applied before first paint. Dark mode changes the app controls while the spreadsheet keeps its white paper background and colors.
• Sheet names as you type: the formula autocomplete lists the other sheets beside functions, named ranges, and tables; accepting one inserts Sheet! (quoted when the name needs it) ready for the cell reference.
• References across sheets while typing: with a formula open and a reference expected, clicking another sheet's tab (or Ctrl/Cmd+PgUp/PgDn) shows that sheet with the edit still alive; clicking or arrowing there inserts Sheet2!B3-style references, and Enter or Escape returns to the cell.
• Replace formulas with values: the Formula menu (right-click) or the palette freezes the selection's formulas into the values they show, spilled array results included, keeping formatting and links; errors are left in place.
• Negative numbers: Format cells offers negatives as -1,234.50, in red, in parentheses, or both for Number and Currency, and any custom format code's section colors ([Red], [Blue], …) color the cell text.
• Image from URL: Insert → Image from URL fetches a PNG, JPEG, GIF, WebP, or SVG through Puter and places it on the sheet like an uploaded picture.
• Pictures in cells: Insert ▸ Image ▸ Place in Cell (from your device, Puter or a URL) makes a picture the cell's value, fitted inside the cell in proportion and aligned by the cell's alignment. It moves, sorts (after the values), filters, copies and undoes with its cell; =A1 shows it, TYPE answers 128 and ISNUMBER/ISTEXT say no. Right-click ▸ Edit Alt Text… gives it a description (IMAGE(url, "alt text", sizing) does the same for a formula's picture), and Place over Cells lifts it out to float; a floating picture's menu or Picture Format ▸ Place in Cell puts it back into the cell under its corner. A pasted picture offers both in its Paste Options. In .xlsx they are the standard in-cell rich values (local images with their alt text, and IMAGE() results from the web as web images), so other programs show them too. The accessibility check lists cell pictures with no alt text.
• Pictures of cells: Paste Special ▸ Picture pastes a picture of the copied range; Paste Special ▸ Linked Picture pastes one that keeps showing those cells (values, number formats, fills, fonts, borders, merged cells and cell pictures, without gridlines) as they change, follows inserted rows and renamed sheets, and shows its reference (=Sheet1!$A$1:$C$5) in the formula bar, where typing another range retargets it; double-click goes to the cells. Saved to .xlsx as a picture of the cells naming its range, so it stays linked elsewhere.
• Picture Format: a selected picture brings its own tab. Corrections (brightness and contrast presets previewed on the picture, or exact values in Picture Corrections), Color (grayscale), Transparency, Reset Picture and Reset Picture & Size; Picture Styles (white or black frames, a thin border, drop shadow, rounded corners, oval); Alt Text; Arrange; and Size: Crop with eight handles (drag or arrow keys) and aspect-ratio presets, the picture staying where it is on the sheet, plus exact height and width with Lock aspect ratio. All of it prints, copies, undoes and round trips through .xlsx as DrawingML (brightness/contrast, grayscale, alpha, outline, preset shape and shadow).
• CSV encodings: imported text files are read as UTF-8 (with or without a BOM), as UTF-16 when a byte-order mark says so, and as Windows-1252 when the bytes are not valid UTF-8, so accented names survive files from older Windows programs.
• Import from URL: File → Import from URL fetches a .csv, .tsv, .xlsx, or .ods from a web address through Puter and adds its sheets to the open spreadsheet (the format is read from the address or sniffed from the bytes).
• Editing together: Share → Start editing together lets several people work in one spreadsheet at once. Everyone sees the others' edits within a second or two (cell values and formulas, formatting, inserted, deleted and moved rows and columns, added, renamed, moved and deleted sheets, settings) without overwriting each other: changes go through one ordered log, and a formula typed while someone inserted rows above it is rewritten as the workbook rewrites its own. Each person's initials sit beside Share (a click goes to where they are), their selection is outlined on the grid in their colour with their name, and the sheet tabs show who is on which sheet. The owner hands out invitation links that let people edit or only view (enforced by the owner's own collaboration server, a Puter Worker, not only by the interface), invites people by username, changes or removes access, and can stop at any time. Undo takes back only your own changes, and leaves alone what others changed since. Edits made offline wait on the device (through a reload too) and merge when the connection returns; the status says Live, Syncing or Offline with what is waiting. The .xlsx file stays the copy the owner keeps: it is written back as people work, so it opens anywhere. See docs/collaboration.md.
• Send by email: File → Share → Send a copy emails the workbook as it is now to up to 20 addresses, with a subject and a message, from the signed-in user (replies go to them): as an .xlsx, as a PDF of the whole workbook, the sheet or the selection (built in the app, laid out on each sheet's paper and orientation, scaled to the page width or split across pages), or the sheet or selection as .csv. The copy leaves out Show Changes' record of earlier cell values, as every download does. Send a link shares the file with each address (Can view or Can edit; someone without a Puter account is invited) and emails them a link that opens it; the owner of a live workbook sends an invitation into it. The Share dialog offers Email a link too. Addresses are checked as they are typed, attachments are capped at 7 MB, the dialog shows what is attached and how large it is, and after a partial failure it keeps just the addresses that were not reached. Mail goes through the app's own email worker (src/workers/email-worker.js, adapted from the Calendar app's), called with the user's Puter session and billed to them; it composes every message itself, accepts only workbook attachments it recognizes and links to the app, sends each person a message of their own, and caps how much one user can send a day. No credential is ever put in a request.
• Threaded comments with @mentions: typing @ in a comment or reply lists the people who can be mentioned (the members of a live workbook, the people the file is shared with, the workbook's other commenters), narrowed as you type; a Puter username or an email address can be typed in full. A posted comment keeps whom it mentions, shows them highlighted, and carries them in .xlsx threaded comments (each comment's mentions list against the workbook's people). Anyone mentioned who cannot open the workbook is offered a share first (Can view or Can edit), then each is emailed the comment, its cell and a link that opens the workbook at that cell (a Puter user known by username at their Puter mailbox), once a save has put the comment in the file (with AutoSave off, when you save, even should the tab be closed first and its edits saved from the draft later). Whoever has the workbook open sees a mention of them as it arrives, and on opening it the mentions they have not seen yet, with a button that goes to the comment. A comment that mentions someone can also assign its thread to them: the card says who it is assigned to, resolving the thread marks it done, and the person is told it is theirs (the assignment travels in the app's own file and live workbooks, not in .xlsx).
• Version history: File → Version history lists snapshots of the file kept under Spreadsheets/.versions/<name> ~<file id>/ — one is written on its own about every 10 minutes of saving, and any can be saved by hand with a label. Restore brings a snapshot back (the current state is kept as a version first); unlabeled snapshots beyond 30 are pruned, labeled ones stay. The history belongs to the file, not to its name: renaming or moving it, in the app or on the Puter desktop, keeps the history with it, and the next snapshot brings the folder back to the name in use. A history left behind by a file deleted or renamed outside the app before it was kept that way is set aside, its snapshots kept, when another file takes that name, so no file lists or restores a stranger's snapshots.
• Show Changes: Review → Show Changes (also File → Show changes, and Show Changes on the cell menu for the selected cells) opens a pane listing the recent edits newest first: who made each one (the signed-in Puter user), when, where, and what the cell held before and after, formulas shown as formulas. A paste or fill is one card that opens onto the cells it changed; rows and sheets inserted or deleted, and undo and redo, are listed by name. A click selects the cells. The list narrows to the sheet shown and to the selection or a typed range, and older edits load on demand. The record keeps the last 1,000 edits (up to 100 cells listed each) and travels with the file in the app's own sidecar part and in drafts, but not in a downloaded or exported copy, so what cells used to say stays with the file on your drive; it is not part of undo, and Clear empties it after asking. In a shared workbook each person's edits are listed under their own name. The pane links on to Version history.
• Nothing lost: unsaved edits are also copied to the browser's local storage moments after they are made. If a tab closes while offline or a save fails, opening the file again offers to restore those changes (or discard them and keep the file as it is); when the file was saved since, what it holds is kept as a version before the older edits replace it. A draft the file already holds is dropped quietly. Edits made while that offer waits are kept beside it, and when a later open finds both — under the file's own name, or under one a rename elsewhere gave it — the later edits are offered and the earlier draft moves to the home screen's Unsaved spreadsheets list, so neither is lost. Two tabs of one file each keep their own edits the same way. The status pill says when a book is too large for the browser to keep a copy of. A file renamed elsewhere while it is open is followed to its new name, and one deleted elsewhere asks whether to save it as a new file, put it back, or keep editing. A file changed elsewhere asks whose version wins (overwriting keeps theirs as a version first, and asks again should that fail), a save made in the very second this tab last saw the file included: modification times are whole seconds, so the file itself is read back before such a save is overwritten. Leaving the editor with that undecided is not refused: the leave dialog offers to go, with the edits kept on this device and offered again on the next open. Spreadsheets that never completed their first cloud save can be recovered from the home screen's Unsaved spreadsheets list, including while offline, and so can the edits kept for a file deleted since — also when another spreadsheet has been saved under its name meanwhile, which neither takes those edits for its own nor writes over them. Local drafts, print settings, and the lists of recently opened files and of those saved outside the app folder are scoped to the signed-in Puter account. Older, unscoped browser records are retained but are not automatically offered to an account because their owner cannot be verified.
• Copy several ranges: ranges added with Ctrl/Cmd+click copy together when they line up — the same rows side by side, or the same columns one under another — and paste as one block.
• Copy what you see: copying or cutting a range that spans hidden or filtered-out rows (or hidden columns) takes only the visible cells, so a filtered list pastes as the rows on screen.
• Menu bar: File, Edit, View, Insert, Format, Data, Tools, and Help sit under the document title, above the toolbar, and hold every action with its shortcut (submenus for paste special, freeze, group, number formats, alignment, borders, cell styles, and the like). Hovering another title while a menu is open switches to it, Left and Right arrows do the same, and toggles such as gridlines or bold show their current state.
• Search the menus: Ctrl/Cmd+Shift+P (or Alt+/, or the search button in the top bar) opens a command palette listing every action by name with its shortcut: type a few letters ("freeze", "pivot", "currency"), arrow to the one you mean, Enter runs it. Opened with nothing typed, the actions you used last come first.
• Options (File → Options, Tools → Options, the account menu, or Ctrl/Cmd+,): one dialog with a search box over its sections that finds any option by a word of its name. General: theme, regional format, whether the app opens on the start screen, and the font, size, sheet count and view a new workbook starts with, and the name written on your comments and changes (your Puter account's unless you choose another). Formulas: this workbook's calculation mode and iterative calculation (saved with the workbook, and labelled as such), how new workbooks calculate, and the error checking rules. Editing: where Enter moves (down, right, up, left, or nowhere), a fixed decimal point, editing in the cell or the formula bar, AutoComplete, Flash Fill offered as you type, carrying a list's formats and formulas onto a new row, how two-digit years are read, the fill handle and dragging cells, a warning before a drag replaces data, the Paste and Auto Fill Options buttons, and a warning before a command changes very many cells. View: formula bar, status bar, sheet tabs, scroll bars, headers on new sheets, comment and note indicators (with hover, without, or none) and showing or hiding all objects. Proofing (AutoCorrect, spelling), Save (AutoSave by default, how soon unsaved edits are copied into the browser), Accessibility (a stronger selection, reduced motion) and Privacy (AI features on or off). Changes apply at once and follow your Puter account to other devices.
• Quick Access Toolbar: the row beside the title holds AutoSave, Save, Undo and Redo, and any other command: right-click a ribbon button → Add to Quick Access Toolbar, tick common commands in the toolbar's own arrow menu, or pick from every command in File → Options → Quick Access Toolbar, where they can be reordered. It can sit below the ribbon and show command names, and is kept for your account.
• Customize the ribbon (File → Options → Customize Ribbon, or right-click the ribbon): show or hide tabs, rename and reorder them, and build tabs and groups of your own holding any commands, on your own tabs or the built-in ones; Restore Defaults puts the ribbon back.
• Keyboard shortcuts of your own (File → Options → Keyboard Shortcuts): every command with the keys that run it, searchable by name or keys. Press a new combination to give a command a shortcut; the dialog says which command it would be taken from and refuses chords the browser or typing needs. Built-in shortcuts can be turned off or moved, and the menus, the palette and the ribbon's tooltips show the keys in force.
• Accessibility: the grid is a real role="grid" with the active cell exposed through aria-activedescendant, every selection change is announced through a live region, menus and dialogs trap focus and close on Escape (which also dismisses a notice at the foot of the screen, as does the close button of one that offers an action), the home list marks itself busy while it loads and then says how many spreadsheets it found or what a search matched, a sign-in that is waiting on Puter says so in a line of its own, toolbar buttons expose pressed state and have 44px touch targets (as do a notice's Undo and Dismiss; the smaller controls of the bars, such as the menu titles, the sheet tab's options button and the zoom controls, get 40px touch zones too), the screen shown while a spreadsheet is opened or a file imported says what it is waiting for through a live region rather than a spinner alone, reduced motion is respected, colors meet WCAG contrast in both themes (a chart's series take the theme's own palette, keep it in Windows High Contrast, where they are the picture, and print on white paper whatever the screen theme).

How it is built

src/
  core/               pure logic, no DOM
    cell.js           A1 notation
    refs.js           reference parsing and rewriting (copy, insert, delete, rename)
    formula/          tokenizer, parser, evaluator, the function library, and
                      LAMBDA values (lambda.js)
    format.js         input parsing, display formatting, named number formats
    numfmt.js         spreadsheet number format codes (custom formats, TEXT())
    workbook.js       the document model: sheets, cells, lazy evaluation, undo,
                      spilled arrays, merges, notes, names, filters, rules,
                      validations, charts and images, links, groups, protection,
                      moving and reordering
    charts.js         chart model and the data read from a range
    chart-special.js  hierarchies, box statistics, stock columns and surface bands for charts
    tables.js         tables and structured references (Table1[Column])
    subtotal.js       subtotal rows and their outline groups
    auto-outline.js   Auto Outline, Clear Outline and outline styles from summary formulas
    custom-cell-styles.js  the workbook's named cell styles: parts, applying, merging
    importrange.js    IMPORTRANGE, IMPORTDATA, IMPORTHTML, IMPORTXML helpers
    formula/query.js  the QUERY language: parser and executor
    aiformula.js      prompts for the AI formula helper and reading formulas from replies
    change-history.js the record of recent edits behind Show Changes
    pivot.js          pivot tables as live formulas
    clipboard.js      HTML tables for and from the system clipboard
    selection.js      selection and keyboard navigation rules
    search.js         find and replace
    condformat.js     conditional formatting rules
    validation.js     data validation rules
    textfit.js        word wrapping for row auto-fit
    io.js             .xlsx / .csv import and export through SheetJS
    sample.js         the sample budget
    templates.js      the template workbooks (invoice, to-do list, loan, ...)
  lib/
    puter.js          every call to the Puter SDK
    doc.js            the open document: save, autosave, rename, export, drafts, version snapshots
    drafts.js         unsaved edits kept in the browser until the file holds them
    versions.js       version history snapshots under Spreadsheets/.versions
    recent.js         recently opened files (KV), for the home screen
    made.js           spreadsheets the app saved outside its folder (Puter's Save dialog), for the home screen
    session.js        sign-in state (nobody, or who) and settings
  ui/                 grid, toolbar, formula bar, sheet tabs, the menu bar
                      (menubar.js), popover menus with submenus (menu.js), the
                      command palette (palette.js), dialogs,
                      chart rendering (chartsvg.js), the color picker, and the
                      fill-series, sort, pivot, validation, and version-history dialogs
  views/              home (file list), editor, gate (SDK error, sign-in for a cloud file)
  vendor/xlsx.mjs     SheetJS Community Edition 0.20.3 (Apache-2.0), vendored
  vendor/words-en.js  English word lists for the spelling checker, from SCOWL
                      (MIT AND BSD; generated by dev/generate-word-lists.py)

The grid is virtualized: only the cells in view exist in the DOM, headers follow the scroll with a transform, and selection, fill preview, formula reference highlights, and the in-cell editor are overlays inside the same scrolling canvas.

Evaluation is lazy with a cache that is dropped whole on every change, so rendering a screen of cells computes exactly what those cells depend on. Cycles are detected and reported as #CYCLE! instead of hanging. Formulas that can produce an array are found statically from their syntax tree and settled sheet-wide before any cell is read, so blank cells know which spill covers them.

Storage on Puter

Where	What	Why
FS Spreadsheets/<name>.xlsx	each document, whole	a real file the user owns; opens anywhere
Spreadsheets/.versions/<name> ~<file id>/*.xlsx	version history snapshots	one per ~10 minutes of saving, 30 unlabeled kept; the id keeps the history with the file through any rename
KV spreadsheet:settings:v1	theme and regional format (this browser's storage without a session)	tiny, hot, one read at boot
FS Spreadsheets/Scripts/<name>.js	My Scripts, the user's own scripts	plain files the user can see; usable in any workbook
KV spreadsheet:script-trust:v1:<sha256>	scripts from files the user has agreed to run	asked once per script, on every device
KV spreadsheet:pref:<name>	AutoCorrect settings, the custom dictionary, spelling and translation choices (also kept in this browser, per account)	follow the account to another device

Files are never stored in KV. The XLSX exporter supplements SheetJS Community Edition with native cell styles (fonts, colors, borders and alignment), blank formatted cells, row/column defaults, table styles, frozen panes, tab colors, and sheet views. Row heights use points and column widths use the exported Normal font, so Excel gets the same geometry. Standard charts keep native DrawingML series linked to worksheet cells. Images and text boxes also have native drawing records; imported SVG artwork and complex chart layouts are rendered as pictures during browser export.

Imported dashboards retain nested charts, linked KPI text, the active sheet, and sheet zoom. PivotChart plots omit the trailing total when the file's point count excludes it, and retain overlapping bars and value labels. Embedded in-cell pictures remain image values through references and lookups and save as native Excel rich values. Excel data-model pivots remain saved result cells; refreshing their model or operating Excel slicers is not supported.

A very-hidden sheet named _puter_meta keeps JSON for the app's original style overrides and inheritance, editable chart/image models, conditional formatting, row/column groups, protection, and other settings. Other apps ignore this sheet; this app reads it back. From a file another program wrote, the frozen panes, tab colours, gridlines setting, sheet protection, row and column groups, default row heights, solid cell fills, borders, alignment, custom table styles, and fonts (family, bold, italic, underline, strikethrough, size, and colour) are read from the file itself, including custom indexed color palettes, the sidecar's own record winning where both exist. Calibri workbooks keep fractional font sizes and compact text spacing, with a bundled Carlito fallback for systems without Calibri and ChromeOS Caladea for systems without Cambria. Original font names remain intact in native exports. Tables explicitly styled as None retain their cell formatting without an added table theme. Imported sheets retain their native default vertical alignment on blank cells and new entries, including when sheets with different defaults are combined. Excel formula and cell-comparison conditional formats import with their priority, stop rules, fills and borders, including relative named references used by Gantt schedules. Text contains, does-not-contain, starts-with and ends-with rules, nonblank-cell rules, and data bars with numeric or minimum/maximum bounds also import, including bars that hide their numeric value. All 17 standard three-, four- and five-icon families import and export natively, with number, percent, percentile and formula boundaries, exclusive comparisons, reversed order and icon-only display. Their boundaries remain editable and survive copies and range moves; the grid and print use shared vector icons. Office extension/custom icon sets are not supported yet. Other native conditional-format types are not read yet. Imported rules survive saves through the app's sidecar. For newly saved files, supported native rule edits, deletions, additions and priority changes take precedence over stale conditional-format metadata; unchanged rules keep their editable app settings. Native color-scale and data-bar thresholds retain lowest/highest value, number, percent and percentile types through copies and saves, with editable threshold types in the manager. Partial cuts and range moves carry conditional formats, including visible-cell selections, and keep dependent conditional formulas linked to moved cells. The manager accepts comma-separated apply-to areas and edits compatible adjacent pieces together, including imported multi-area rules. Unlabelled, unlinked Excel form checkboxes over empty cells import as editable checkbox cells, retaining their checked state and square appearance. Linked, labelled, macro-driven and mixed-state form controls are not converted. These checkboxes survive saves in this app's sidecar rather than being exported as native Excel form controls. Values, formulas (with cached results; spilled arrays as legacy array formulas; newer functions carry the _xlfn. prefix Excel expects, and files from Excel have it stripped on the way in), number formats including custom codes, hyperlinks, column widths, row heights, hidden rows, columns, and sheets, merged cells, notes (as comments), named ranges, and the autofilter range with its conditions are all standard .xlsx and round-trip with any spreadsheet program. A formula this app cannot read (=1+, shown as #ERROR!) is saved as the text =1+ under the cell's own number format rather than as a formula, so Excel opens the file without a repair prompt; the sidecar carries the formula and this app restores it on opening (the same goes for .ods with its settings block). A formula in another program's file that reaches into another workbook ([1]Sheet1!A1) keeps the value that file cached, as there is no other workbook to read here, and is never written back as a formula; the sidecar keeps its text.

When the app runs inside the Puter desktop (puter.env === 'app') the desktop owns the session, so no sign-out is offered and exports go through Puter's own save dialog instead of a browser download.

Analytics

The production page loads Plausible for pageviews and four value events. Create matching custom event goals under the site's Plausible settings → Goals:

Event	When it fires	Properties
Spreadsheet Edited	First successful data change in an editor session, including typing, pasting or AI-made changes	None
Spreadsheet Saved	A cloud write completes, including autosaves and Save a copy	method: manual, auto or copy
Spreadsheet Exported	A browser download starts or Puter's save picker completes, including selection and chart exports	format, method: browser or puter
AI Interaction	A nonempty AI answer arrives; sidebar chats count once after the completed exchange	feature; sidebar replies also report whether they changed the workbook

AI features are assistant, formula, translate, detect-language, ask-data, explain-formula and generate-formula. Failed, cancelled, empty or truncated sidebar replies do not count. An unchanged save does not count. Browser exports measure the download being started, since the page cannot tell whether the user saved it to disk.

No spreadsheet contents, filenames, paths, prompts, replies or account identifiers are included in custom event properties. Analytics failures never block app actions. The development mock and phone harness omit the tracking script. Tests use a stubbed plausible function rather than sending events to the live site.

Development

npm install
npm run dev        # http://localhost:5173
npm test           # vitest
npm run build      # production build in dist/
npm run preview    # serve dist/

Two dev harnesses (not part of the production build):

• /mock.html runs the whole app against an in-memory mock of the Puter SDK (dev/puter-mock.js), so no Puter account is needed. Add ?env=app to simulate the Puter desktop or ?signedout to start without a session.
• /dev/phone.html shows the mock app in phone- and tablet-sized frames.

In /mock.html, editing together runs against a room worker inside the page (dev/collab-mock.js); window.__collabDemo.addPerson('maria') adds a simulated collaborator to the shared workbook that is open, whose RoomClient can then edit and move about. npm run build:worker bundles the room worker into public/worker/spreadsheet-worker.js (part of npm run build).

Email in /mock.html runs the real email worker inside the page (dev/email-mock.js): nothing is sent, and each message it would send is kept in window.__mailbox and logged. Addresses at bounce.test fail and addresses at optout.test have opted out. npm run deploy:email-worker deploys the worker as spreadsheet-email (done once, by the app owner).

Tests

tests/ covers the formula tokenizer, parser, and evaluator, the whole function library (including dynamic arrays and spilling), reference rewriting for copy/insert/delete/rename, input parsing, number formatting and format codes, the workbook model (undo/redo, transactions, structural edits, moving and reordering, fill, sort, sheets, merges, notes, names, links, filters, conditional formatting, validation, charts), the rich clipboard, chart data and SVG output, find and replace, autocomplete context, .xlsx and .csv round trips through SheetJS, selection and keyboard navigation, the document controller against a mocked Puter, the print table, and the grid's DOM behavior under jsdom.

Deploying

dist/ is fully static and built with relative paths, so it can be hosted anywhere, including Puter's own hosting. The app talks to Puter directly from the browser; there is no server.

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License

This app, including all its contents, modules, and components, is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0-only). Third-party libraries included in this app may be subject to their own licenses.