CacheStorage.open()

The open() method of the CacheStorage interface returns a Promise that resolves to the Cache object matching the cacheName.

You can access CacheStorage through the global caches property.

Note: If the specified Cache does not exist, a new cache is created with that cacheName and a Promise that resolves to this new Cache object is returned.

Syntax

caches.open(cacheName).then(function(cache) {
  // Do something with your cache
});

Parameters

cacheName

The name of the cache you want to open.

Return value

A Promise that resolves to the requested Cache object.

Examples

This example is from the MDN sw-test example (see sw-test running live). Here we wait for an InstallEvent to fire, then runs waitUntil() to handle the install process for the app. This consists of calling CacheStorage.open() to create a new cache, then using Cache.addAll() to add a series of assets to it.

self.addEventListener('install', function(event) {
  event.waitUntil(
    caches.open('v1').then(function(cache) {
      return cache.addAll([
        '/sw-test/',
        '/sw-test/index.html',
        '/sw-test/style.css',
        '/sw-test/app.js',
        '/sw-test/image-list.js',
        '/sw-test/star-wars-logo.jpg',
        '/sw-test/gallery/bountyHunters.jpg',
        '/sw-test/gallery/myLittleVader.jpg',
        '/sw-test/gallery/snowTroopers.jpg'
      ]);
    })
  );

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
open
40
16
44
Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.
No
27
11.1
40
40
44
27
Yes
4.0

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/CacheStorage/open