diff --git a/.gitignore b/.gitignore
index 07e49ff7b..469bccb47 100644
--- a/.gitignore
+++ b/.gitignore
@@ -72,3 +72,4 @@ rest-api-spec
 yaml-rest-tests
 generated-tests
 schema
+base64-data
diff --git a/package.json b/package.json
index aa28671f8..8c2a90edb 100644
--- a/package.json
+++ b/package.json
@@ -70,6 +70,7 @@
     "chai": "5.2.1",
     "cross-zip": "4.0.1",
     "desm": "1.3.1",
+    "inly": "^5.0.1",
     "into-stream": "8.0.1",
     "js-yaml": "4.1.0",
     "license-checker": "25.0.1",
diff --git a/test/ingest/README.md b/test/ingest/README.md
new file mode 100644
index 000000000..c63f26a53
--- /dev/null
+++ b/test/ingest/README.md
@@ -0,0 +1,5 @@
+To run the base64 benchmark test:
+
+1. Install dependencies: `npm install`
+2. Set environment variables `ES_URL`, `ES_USERNAME` and `ES_PASSWORD`
+3. Run the script: `node test/ingest/base64.mjs`
diff --git a/test/ingest/base64.mjs b/test/ingest/base64.mjs
new file mode 100644
index 000000000..dcf290b55
--- /dev/null
+++ b/test/ingest/base64.mjs
@@ -0,0 +1,170 @@
+/*
+ * Copyright Elasticsearch B.V. and contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { readFile } from "node:fs/promises"
+import { existsSync, createWriteStream, mkdirSync } from "node:fs"
+import { Readable } from "node:stream"
+import { finished } from "node:stream/promises"
+import inly from 'inly'
+import { Client } from '../../index.js'
+import { Serializer } from '@elastic/transport'
+
+const client = new Client({
+  node: process.env.ES_URL,
+  auth: {
+    username: process.env.ES_USERNAME,
+    password: process.env.ES_PASSWORD,
+  },
+  compression: false
+})
+
+const indexName = "b64-test"
+
+const indexSettings = {
+  index: indexName,
+  wait_for_active_shards: 'all',
+  mappings: {
+    properties: {
+      docid: { type: "keyword" },
+      emb: {
+        dims: 1536,
+        index: true,
+        index_options: { type: "flat" },
+        similarity: "cosine",
+        type: "dense_vector"
+      },
+      text: {
+        fields: {
+          keyword: {
+            ignore_above: 256,
+            type: "keyword"
+          }
+        },
+        type: "text"
+      },
+      title: {
+        type: "text"
+      }
+    }
+  }
+}
+
+const dataset_size = 20000
+
+/**
+ * Fetches vector data set
+ */
+async function fetchDataSet () {
+  const url = 'https://rally-tracks.elastic.co/openai_vector/open_ai_corpus-initial-indexing-1k.json.bz2'
+  const dir = 'base64-data'
+  const filePath = `./${dir}/open_ai_corpus-initial-indexing-1k.json`
+  const filePathBz2 = `./${dir}/open_ai_corpus-initial-indexing-1k.json.bz2`
+
+  if (!existsSync(filePath)) {
+    mkdirSync(dir, { recursive: true })
+
+    // download archive
+    if (!existsSync(filePathBz2)) {
+      console.log(`Downloading ${url}`)
+      const { body } = await fetch(url)
+      const stream = createWriteStream(filePathBz2)
+      await finished(Readable.fromWeb(body).pipe(stream))
+    }
+
+    // extract archive
+    await new Promise((resolve, reject) => {
+      console.log(`Extracting ${filePathBz2} to ${dir}`)
+      const extract = inly(filePathBz2, dir)
+      extract.on('error', reject)
+      extract.on('end', resolve)
+    })
+  }
+
+  const file = await readFile(filePath, 'utf8')
+  return file.split(/[\r\n]+/)
+    .filter(row => row.trim().length > 0)
+    .map(row => JSON.parse(row.trim()))
+}
+
+/**
+ * Loops over an array until a certain number of records has be yielded
+ */
+function* loopDataSet (data) {
+  let count = 0
+  while (true) {
+    for (const item of data) {
+      yield item
+      count++
+      if (count >= dataset_size) return
+    }
+  }
+}
+
+/**
+  * Bulk ingest the dataset
+  * @param {number} chunkSize number of documents to serialize before running bulk request
+  * @param {boolean} base64 If true, encode float32 embeddings array as a base64 string
+  * @returns {number} Milliseconds the serialize+index operations took
+  */
+async function index (chunkSize, base64 = false) {
+  const data = await fetchDataSet()
+  const serializer = new Serializer()
+  let chunk = []
+
+  await client.indices.create(indexSettings)
+  await client.indices.refresh({ index: indexName })
+
+  const start = Date.now()
+
+  for (const doc of loopDataSet(data)) {
+    if (base64) doc.emb = serializer.encodeFloat32Vector(doc.emb)
+    chunk.push(doc)
+    if (chunk.length >= chunkSize) {
+      const operations = chunk.flatMap(doc => [{ index: { _index: indexName } }, doc])
+      await client.bulk({ operations })
+      chunk = []
+    }
+  }
+
+  const duration = Date.now() - start
+
+  await client.indices.delete({ index: indexName })
+
+  return duration
+}
+
+async function run () {
+  // clean up any existing index, in case a previous run ended in a partially finished state
+  await client.indices.delete({
+    index: indexName,
+    allow_no_indices: true
+  })
+
+  const measurements = []
+
+  for (const chunk_size of [100, 250, 500, 1000]) {
+    const measurement = { dataset_size, chunk_size }
+
+    const float32Duration = []
+    const base64Duration = []
+
+    for (const _ of [1, 2, 3]) {
+      float32Duration.push(await index(chunk_size))
+      base64Duration.push(await index(chunk_size, true))
+    }
+
+    measurement.float32 = { duration: float32Duration.reduce((a, b) => a + b, 0) / float32Duration.length }
+    measurement.base64 = { duration: base64Duration.reduce((a, b) => a + b, 0) / base64Duration.length }
+
+    measurements.push(measurement)
+  }
+
+  console.log(JSON.stringify(measurements, null, 2))
+}
+
+run().catch(err => {
+  console.error(err)
+  process.exit(1)
+})