Firefox3+Safari4+Chrome2+Opera10.6+Edge79+Edge (Legacy)12+Internet Explorer9+Firefox Android?Safari iOS?Chrome Android?WebView Android37+Samsung Internet?Opera Android11+ Messages in server-sent events, cross-document messaging, channel messaging, broadcast channels, and WebSockets use the MessageEvent interface for their message events: [WEBSOCKETS] [Exposed=(Window,Worker,AudioWorklet)] interfac