coderef

Shared worker extended lifetimeLimited availability

The extendedLifetime option of the SharedWorker() constructor gives shared workers extra time to perform operations after all pages using it have been navigated away from or closed.

Not yet supported in all major browsers — check the table and provide a fallback.

How to use ↓Compare browsers

Browser support

DesktopChrome
1–147Not supported
148+Supportedsince May 5, 2026
Current: 155
Edge
12–147Not supported
148+Supportedsince May 7, 2026
Current: 154
Firefox
✕Not supportedup to 157
Current: 157
Safari
✕Not supportedup to 27
Current: 27
MobileChrome Android
18–147Not supported
148+Supportedsince May 5, 2026
Current: 155
Firefox Android
✕Not supportedup to 157
Current: 157
Safari iOS
✕Not supportedup to 27
Current: 27

How 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 — see the links below.

Feature detection

JS · check before using
if ("SharedWorker" in globalThis && "SharedWorker" in SharedWorker.prototype) {
  // SharedWorker.SharedWorker is available
}

Specification