On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Bun version 1.0.0 on 2023-09-08
In Chrome version 36 on 2014-07-16
In Chrome Android version 36 on 2014-07-16
In Deno version 1.0 on 2020-05-13
In Edge version 12 on 2015-07-29
In Firefox version 6 on 2011-08-16 Note: Before Firefox 38, this method threw a TypeError when the key parameter was not an object. However, the ES2015 specification specifies to return undefined instead. Furthermore, WeakMap.prototype.get accepted an optional second argument as a fallback value, which is not part of the standard. Both non-standard behaviors are removed in version 38 and higher.
In Firefox for Android version 6 on 2011-08-16 Note: Before Firefox for Android 38, this method threw a TypeError when the key parameter was not an object. However, the ES2015 specification specifies to return undefined instead. Furthermore, WeakMap.prototype.get accepted an optional second argument as a fallback value, which is not part of the standard. Both non-standard behaviors are removed in version 38 and higher.
In Internet Explorer version 11 on 2013-10-17
In Node.js version 0.12.0 on 2015-02-06
In Quest Browser version 5.0 on undefined
In Opera version 23 on 2014-07-22
In Opera Android version 24 on 2014-09-10
In Safari version 8 on 2014-10-16
In Safari on iOS version 8 on 2014-09-17
In Samsung Internet version 3.0 on 2015-04-10
In WebView Android version 37 on 2014-09-03
In WebView on iOS version 8 on 2014-09-17