Limited support Use with care and provide a fallback when broad support matters.

Shared storage

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The SharedStorage interface of the Shared Storage API represents the shared storage for a particular origin, defining methods to write data to the shared storage.

SharedStorage is the base class for:

WindowSharedStorage, accessed via Window.sharedStorage.

WorkletSharedStorage, accessed via SharedStorageWorkletGlobalScope.sharedStorage.

Security and APIsSecurity

Browser support

Feature Desktop Mobile
Chrome
Edge
Firefox
Safari
Chrome Android
Safari iOS
SharedStorage
Deprecated
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sharedStorageWritable
Deprecated
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sharedStorageWritable
Deprecated
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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.
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clear
Deprecated

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

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

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

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

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