On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Chrome version 80 on 2020-02-04
In Chrome Android version 80 on 2020-02-04
In Deno version 1.0 on 2020-05-13
In Edge version 80 on 2020-02-07
In Firefox version 114 on 2023-06-06
In Firefox for Android version 114 on 2023-06-06
Not in Internet Explorer
In Node.js version 12.17.0 on 2020-05-26 Note: ECMAScript modules are enabled for files ending with .mjs and for files ending with .js when the nearest parent package.json file contains a top-level field "type" with a value of "module".
In Quest Browser version 9.0 on undefined
In Opera version 67 on 2020-03-03
In Opera Android version 57 on 2020-03-30
In Safari version 15 on 2021-09-20 Note: Nested workers support was introduced in Safari 15.5. Script loading in nested workers was introduced in Safari 16.4.
In Safari on iOS version 15 on 2021-09-20 Note: Nested workers support was introduced in Safari on iOS 15.5. Script loading in nested workers was introduced in Safari on iOS 16.4.
In Samsung Internet version 13.0 on 2020-12-02
In WebView Android version 80 on 2020-02-04
In WebView on iOS version 15 on 2021-09-20 Note: Nested workers support was introduced in WebView on iOS 15.5. Script loading in nested workers was introduced in WebView on iOS 16.4.