Limited supportUse with care and provide a fallback when broad support matters.
Security and APIs Limited support

Shared storage

The sharedStorage API stores data to a shared space where the data can then be processed without the ability to track users across the different sites they visit. A common use case is measuring the reach of third-party ads without using user-tracking cookies. It is most useful when native HTML semantics or browser capabilities can replace custom implementation work.

Security and APIsSecurity

Overview

The sharedStorage API stores data to a shared space where the data can then be processed without the ability to track users across the different sites they visit. A common use case is measuring the reach of third-party ads without using user-tracking cookies. It is most useful when native HTML semantics or browser capabilities can replace custom implementation work.

Browser support

Feature Desktop Mobile
Chrome
Edge
Firefox
Safari
Chrome Android
Safari iOS
SharedStorage
Deprecated
126
126
126
sharedStorageWritable
Deprecated
126
126
126
sharedStorageWritable
Deprecated
126
126
126
append
Deprecated

The append() method of the SharedStorage interface appends a string to the value of an existing key-value pair in the current origin's shared storage.
126
126
126
clear
Deprecated

The clear() method of the SharedStorage interface clears the current origin's shared storage, removing all data from it.
126
126
126
createWorklet
Deprecated
126
126
126
delete
Deprecated

The delete() method of the SharedStorage interface deletes an existing key-value pair from the current origin's shared storage.
126
126
126
get
Deprecated
126
126
126
run
Deprecated
126
126
126
selectURL
Deprecated
126
126
126
set
Deprecated

The set() method of the SharedStorage interface either stores a new key-value pair in the current origin's shared storage or updates an existing one.
126
126
126
worklet
Deprecated
126
126
126
SharedStorageWorklet
Deprecated

The SharedStorageWorklet interface of the Shared Storage API represents the shared storage worklet for the current origin.
126
126
126
run
Deprecated
126
126
126
selectURL
Deprecated
126
126
126
SharedStorageWorkletGlobalScope
Deprecated

The SharedStorageWorkletGlobalScope interface of the Shared Storage API represents the global scope of a SharedStorageWorklet module.
126
126
126
register
Deprecated

The register() method of the SharedStorageWorkletGlobalScope interface registers an SharedStorageOperation defined inside the current worklet module.
126
126
126
sharedStorage
Deprecated

The context read-only property of the SharedStorageWorkletGlobalScope interface contains a WorkletSharedStorage object instance, which represents the shared storage for a particular origin as exposed to a worklet context.
126
126
126
sharedStorage
Deprecated

The global read-only sharedStorage property returns the WindowSharedStorage object for the current origin. This is the main entry point for writing data to shared storage using the Shared Storage API.
126
126
126
1+Supported (version) Not supported ※Has note Sub-feature descriptions sourced from MDN Web Docs (CC BY-SA 2.5)

Syntax

HTML 
// Write data
await window.sharedStorage.set('ab-group', 'experiment');

// Readable only within the worklet
await window.sharedStorage.worklet.addModule('worklet.js');
await window.sharedStorage.run('operation');

Use cases

  • Strengthen integration

    Use Shared storage when browser APIs need clearer security boundaries or more explicit capabilities.

  • Connect platform features

    Apply Shared storage when your app benefits from deeper browser or device integration.

Cautions

  • Test Shared storage in your target browsers and input environments before depending on it as a primary behavior.
  • Provide a fallback path or acceptable degradation strategy when support is still limited.

Accessibility

  • Make sure Shared storage supports the intended task without making the page harder to perceive, understand, or operate.

Related links

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