On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Chrome version 81 on 2020-04-07
In Chrome Android version 81 on 2020-04-07
In Edge version 81 on 2020-04-13
In Firefox version 65 on 2019-01-29
In Firefox for Android version 65 on 2019-01-29
Not in Internet Explorer
In Quest Browser version 9.0 on undefined
In Opera version 68 on 2020-04-22
In Opera Android version 58 on 2020-05-13
In Safari version 11.1 on 2018-04-12 Note: Although the onmessageerror property is supported, the messageerror event is never fired. See bug 272967.
In Safari on iOS version 11.3 on 2018-03-29 Note: Although the onmessageerror property is supported, the messageerror event is never fired. See bug 272967.
In Samsung Internet version 13.0 on 2020-12-02
In WebView Android version 81 on 2020-04-07
Not in WebView on iOS