diff --git a/common/api/core-mobile.api.md b/common/api/core-mobile.api.md
index dfe4ba5c9f08..5138b30db0cf 100644
--- a/common/api/core-mobile.api.md
+++ b/common/api/core-mobile.api.md
@@ -41,7 +41,7 @@ export interface CancelRequest {
 }
 
 // @beta (undocumented)
-export type DeviceEvents = "memoryWarning" | "orientationChanged" | "enterForeground" | "enterBackground" | "willTerminate" | "authAccessTokenChanged";
+export type DeviceEvents = "memoryWarning" | "orientationChanged" | "enterForeground" | "enterBackground" | "willTerminate" | "authAccessTokenChanged" | "online" | "offline";
 
 // @internal
 export class DownloadFailed extends BentleyError {
diff --git a/common/changes/@itwin/core-backend/tcobbs-reachability_2025-11-19-19-50.json b/common/changes/@itwin/core-backend/tcobbs-reachability_2025-11-19-19-50.json
new file mode 100644
index 000000000000..009c48fb80d4
--- /dev/null
+++ b/common/changes/@itwin/core-backend/tcobbs-reachability_2025-11-19-19-50.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@itwin/core-backend",
+      "comment": "Mobile: don't do workspace update checks when offline",
+      "type": "none"
+    }
+  ],
+  "packageName": "@itwin/core-backend"
+}
\ No newline at end of file
diff --git a/common/changes/@itwin/core-mobile/tcobbs-reachability_2025-11-19-19-50.json b/common/changes/@itwin/core-mobile/tcobbs-reachability_2025-11-19-19-50.json
new file mode 100644
index 000000000000..dc13eedcfeec
--- /dev/null
+++ b/common/changes/@itwin/core-mobile/tcobbs-reachability_2025-11-19-19-50.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@itwin/core-mobile",
+      "comment": "Added online and offline device events for network reachability monitoring.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@itwin/core-mobile"
+}
\ No newline at end of file
diff --git a/core/backend/src/NativeHost.ts b/core/backend/src/NativeHost.ts
index e21b368d5264..e2e935e34c46 100644
--- a/core/backend/src/NativeHost.ts
+++ b/core/backend/src/NativeHost.ts
@@ -7,7 +7,7 @@
  */
 
 import { join } from "path";
-import { AccessToken, assert, BeEvent, GuidString } from "@itwin/core-bentley";
+import { AccessToken, assert, BeEvent, GuidString, ProcessDetector } from "@itwin/core-bentley";
 import {
   BriefcaseProps, InternetConnectivityStatus, LocalBriefcaseProps, NativeAppFunctions, nativeAppIpcStrings, NativeAppNotifications,
   OverriddenBy, RequestNewBriefcaseProps, StorageValue,
@@ -18,6 +18,7 @@ import { IModelHost } from "./IModelHost";
 import { IpcHandler, IpcHost, IpcHostOpts, throttleProgressCallback } from "./IpcHost";
 import { NativeAppStorage } from "./NativeAppStorage";
 import { CatalogIModelHandler } from "./CatalogDb";
+import { setOnlineStatus } from "./internal/OnlineStatus";
 
 /**
  * Implementation of NativeAppFunctions
@@ -199,6 +200,12 @@ export class NativeHost {
     if (this._reachability !== status) {
       this._reachability = status;
       this.onInternetConnectivityChanged.raiseEvent(status);
+      if (ProcessDetector.isMobileAppBackend) {
+        // Merely referencing NativeHost from a non-native backend causes a runtime exception (even
+        // inside an if statement that checks that the backend is a mobile backend). This allows code
+        // that needs to check connectivity to do so without referencing NativeHost directly.
+        setOnlineStatus(status === InternetConnectivityStatus.Online);
+      }
     }
   }
 }
diff --git a/core/backend/src/internal/OnlineStatus.ts b/core/backend/src/internal/OnlineStatus.ts
new file mode 100644
index 000000000000..c9a83f747ff1
--- /dev/null
+++ b/core/backend/src/internal/OnlineStatus.ts
@@ -0,0 +1,26 @@
+/*---------------------------------------------------------------------------------------------
+* Copyright (c) Bentley Systems, Incorporated. All rights reserved.
+* See LICENSE.md in the project root for license terms and full copyright notice.
+*--------------------------------------------------------------------------------------------*/
+
+let isOnline = true;
+
+/**
+ * Sets the online status of the backend that will be returned by `getOnlineStatus`.
+ * @param online The new online status.
+ * @internal
+ */
+export function setOnlineStatus(online: boolean) {
+  isOnline = online;
+}
+
+/**
+ * Determine whether the backend is currently considered online.
+ * @note This only works if `setOnlineStatus` has been called by something to update the status.
+ * `NativeHost` does this whenever the connectivity changes. If `setOnlineStatus` has never been
+ * called, this will return `true`.
+ * @internal
+ */
+export function getOnlineStatus(): boolean {
+  return isOnline;
+}
diff --git a/core/backend/src/internal/workspace/WorkspaceImpl.ts b/core/backend/src/internal/workspace/WorkspaceImpl.ts
index 4594df59f57e..15be855e48ae 100644
--- a/core/backend/src/internal/workspace/WorkspaceImpl.ts
+++ b/core/backend/src/internal/workspace/WorkspaceImpl.ts
@@ -9,7 +9,7 @@
 import { createHash } from "crypto";
 import * as fs from "fs-extra";
 import { dirname, extname, join } from "path";
-import { AccessToken, assert, BeEvent, DbResult, Mutable, OpenMode } from "@itwin/core-bentley";
+import { AccessToken, assert, BeEvent, DbResult, Mutable, OpenMode, ProcessDetector } from "@itwin/core-bentley";
 import { CloudSqliteError, FilePropertyProps, LocalDirName, LocalFileName, WorkspaceError } from "@itwin/core-common";
 import { CloudSqlite } from "../../CloudSqlite";
 import { IModelHost, KnownLocations } from "../../IModelHost";
@@ -27,6 +27,7 @@ import { CreateNewWorkspaceContainerArgs, CreateNewWorkspaceDbVersionArgs, Edita
 import { WorkspaceSqliteDb } from "./WorkspaceSqliteDb";
 import { SettingsImpl } from "./SettingsImpl";
 import { _implementationProhibited, _nativeDb } from "../Symbols";
+import { getOnlineStatus } from "../OnlineStatus";
 
 function workspaceDbNameWithDefault(dbName?: WorkspaceDbName): WorkspaceDbName {
   return dbName ?? "workspace-db";
@@ -119,6 +120,17 @@ class WorkspaceContainerImpl implements WorkspaceContainer {
     // sharedConnect returns true if we just connected (if the container is shared, it may have already been connected)
     if (cloudContainer.sharedConnect() && false !== props.syncOnConnect) {
       try {
+        if (ProcessDetector.isMobileAppBackend || ProcessDetector.isElectronAppBackend) {
+          // Even though we've already confirmed that we are running in a native app backend,
+          // having code here that references NativeHost causes a runtime exception. So we use
+          // getOnlineStatus to determine whether we're online, which NativeHost keeps up to date.
+          if (!getOnlineStatus()) {
+            // If running in a native app and we're offline, don't check for changes.
+            // Doing so will fail and be caught below, but it has to wait for the network
+            // timeout.
+            return;
+          }
+        }
         cloudContainer.checkForChanges();
       } catch {
         // must be offline
diff --git a/core/mobile/src/backend/MobileHost.ts b/core/mobile/src/backend/MobileHost.ts
index cbd267b7c78d..138ab3926918 100644
--- a/core/mobile/src/backend/MobileHost.ts
+++ b/core/mobile/src/backend/MobileHost.ts
@@ -5,7 +5,7 @@
 
 import { AccessToken, BeEvent, BriefcaseStatus } from "@itwin/core-bentley";
 import { IpcHandler, IpcHost, NativeHost, NativeHostOpts } from "@itwin/core-backend";
-import { IpcWebSocketBackend, RpcInterfaceDefinition } from "@itwin/core-common";
+import { InternetConnectivityStatus, IpcWebSocketBackend, OverriddenBy, RpcInterfaceDefinition } from "@itwin/core-common";
 import { CancelRequest, DownloadFailed, UserCancelledError } from "./MobileFileHandler";
 import { ProgressCallback } from "./Request";
 import { mobileAppStrings } from "../common/MobileAppChannel";
@@ -58,6 +58,12 @@ export abstract class MobileDevice {
       case "authAccessTokenChanged":
         MobileHost.onAuthAccessTokenChanged.raiseEvent(args[0], args[1]);
         break;
+      case "online":
+        NativeHost.overrideInternetConnectivity(OverriddenBy.Browser, InternetConnectivityStatus.Online);
+        break;
+      case "offline":
+        NativeHost.overrideInternetConnectivity(OverriddenBy.Browser, InternetConnectivityStatus.Offline);
+        break;
     }
   }
 
diff --git a/core/mobile/src/common/MobileAppProps.ts b/core/mobile/src/common/MobileAppProps.ts
index 5c529801ca00..1d3d3ab41f19 100644
--- a/core/mobile/src/common/MobileAppProps.ts
+++ b/core/mobile/src/common/MobileAppProps.ts
@@ -33,7 +33,7 @@ export interface MobileNotifications {
 }
 
 /** @beta */
-export type DeviceEvents = "memoryWarning" | "orientationChanged" | "enterForeground" | "enterBackground" | "willTerminate" | "authAccessTokenChanged";
+export type DeviceEvents = "memoryWarning" | "orientationChanged" | "enterForeground" | "enterBackground" | "willTerminate" | "authAccessTokenChanged" | "online" | "offline";
 
 /**
 * The methods that may be invoked via Ipc from the frontend of a Mobile App that are implemented on its backend.