web-feature: alpha()

Widely available

The alpha() CSS function computes a relative color value by adjusting the opacity of an origin color.

WKWebView

macOS

*

iOS

*

Android WebView

Android

*

WebView2

Windows

*

WPE MiniBrowser

Linux

2026-10

Servo

Android

2026-10

ArkWeb

HarmonyOS

*

Chrome Browser

Android

151

Safari Browser

iOS

27