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 persist method of the StorageManager interface requests permission to use persistent storage, and returns a Promise that resolves to true if permission is granted and box mode is persistent, and false otherwise.

Syntax { ... })



Return value

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 'persist' 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

 Last updated by: chrisdavidmills,