MDN’s new design is in Beta! A sneak peek:

Secure context
This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The persisted property of the StorageManager interface returns a Promise that resolves to true if box mode is persistent for your site's storage.

Syntax { ... })




A Promise that resolves to a Boolean.


if ( && {
    if (persistent)
      console.log("Storage will not be cleared except by explicit user action");
      console.log("Storage may be cleared by the UA under storage pressure.");


Specification Status Comment
The definition of 'persisted' in that specification.
Living Standard Initial definition.

Browser Compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 55.0 55 (55) ? 42 ?
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support 55.0 ? ? ? 42 ? 55.0

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, shawn_huang, bunnybooboo, jpmedley
 Last updated by: chrisdavidmills,