fetchLaterLimited availability
The fetchLater() method requests a deferred fetch sent at an unknown time. The browser chooses a reliable time to send the request, ideally when the document is unloaded, and ignores the response. This API is useful for sending beacons to a server without expecting a particular response.
Not yet supported in all major browsers — check the table and provide a fallback.
Browser support
DesktopChrome
1–134Not supported
135+Supportedsince Apr 1, 2025
Current: 155Edge
12–134Not supported
135+Supportedsince Apr 4, 2025
Current: 154Firefox
✕Not supportedup to 157
Current: 157Safari
✕Not supportedup to 27
Current: 27MobileChrome Android
18–134Not supported
135+Supportedsince Apr 1, 2025
Current: 155Firefox Android
✕Not supportedup to 157
Current: 157Safari iOS
✕Not supportedup to 27
Current: 27How to use
Not supported in Firefox, Safari, Firefox Android, Safari iOS. Use feature detection below and provide a fallback (or a polyfill) for those browsers.
Example
Full syntax and examples are on MDN: FetchLaterResult.
Feature detection
JS · check before using
if ("Window" in globalThis && "fetchLater" in Window.prototype) {
// Window.fetchLater is available
}Documentation (MDN)
Specification
Sub-features
Support for each part of the feature (5). The overall table above shows when the whole feature works.
| Sub-feature | Chrome | Edge | Firefox | Safari | Chrome Android | Firefox Android | Safari iOS |
|---|---|---|---|---|---|---|---|
| FetchLaterResult | 135 | 135 | ✕ | ✕ | 135 | ✕ | ✕ |
| FetchLaterResult.activated | 135 | 135 | ✕ | ✕ | 135 | ✕ | ✕ |
| Window.fetchLater | 135 | 135 | ✕ | ✕ | 135 | ✕ | ✕ |
| http.headers.Permissions-Policy.deferred-fetch | 135 | 135 | ✕ | ✕ | 135 | ✕ | ✕ |
| http.headers.Permissions-Policy.deferred-fetch-minimal | 135 | 135 | ✕ | ✕ | 135 | ✕ | ✕ |