Background Sync API browser support

The Background Synchronization API lets a page register a named sync task with its service worker; the browser fires a sync event in the service worker once the device has connectivity, even if the page has been closed in the meantime.

The table covers the Background Synchronization API as recorded in MDN browser-compat-data. Rows marked as unsupported carry the vendor tracking bug in their footnote where one exists.

• Legend
• Yes
• Partial
• Flag
• No
• Unknown

Browser / Platform	Support	Versions	Confidence	Source	Notes
Chrome (Desktop)	Yes	49	high	source	—
Chrome (Android)	Yes	49	high	source	1
Edge (Desktop)	Yes	79	high	source	2
Firefox (Desktop)	No	—	high	source	3
Firefox (Android)	No	—	high	source	45
Safari (macOS)	No	—	high	source	6
Safari (iOS)	No	—	high	source	78
Samsung Internet	Yes	5.0	high	source	9
WebView (Android)	No	—	high	source	10

1. Derived by browser-compat-data mirroring from Chrome.
2. Derived by browser-compat-data mirroring from Chrome.
3. No Firefox support is recorded in browser-compat-data.
4. No Firefox for Android support is recorded in browser-compat-data.
5. Derived by browser-compat-data mirroring from Firefox.
6. Implementation tracking: https://webkit.org/b/182565.
7. Implementation tracking: https://webkit.org/b/182565.
8. Derived by browser-compat-data mirroring from Safari.
9. Derived by browser-compat-data mirroring from Chrome Android.
10. Implementation tracking: https://crbug.com/40449796.

Source data: /compatibility/background-sync.json · Global usage: 72 % (StatCounter 2026-05)

Source: spec · MDN · Last verified 2026-10-03 · Confidence: high (computed from sources)

See also

• Background sync: retrying failed requests
• Web Background Synchronization (wicg.github.io)
• Background Synchronization API (developer.mozilla.org)