web-feature: Map (initial support)

Widely available

Map objects hold key-value pairs and remember the original insertion order of the keys.

WKWebView

macOS

*

iOS

*

Android WebView

Android

*

WebView2

Windows

*

WPE MiniBrowser

Linux

2026-07

Servo

Android

2026-07

ArkWeb

HarmonyOS

*

Chrome Browser

Android

38

Safari Browser

iOS

8