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Tags: api

The when() method on a event target returns an Observable object, which provides a declarative API for subscribing to and operating on events. It's an alternative to addEventListener() callbacks.

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Specifications

Observable, from Web Platform Incubator Community Group (W3C).

Browser support

Chrome 135 Released on 2025-04-01
Chrome Android 135 Released on 2025-04-01
Edge 135 Released on 2025-04-04
Firefox ❌ Vendor position (concerns: complexity, venue)
Firefox for Android ❌ Vendor position (concerns: complexity, venue)
Safari ❌ Vendor position : support (concerns: venue)
Safari on iOS ❌ Vendor position : support (concerns: venue)

Web Platform Tests (WPT)

View the latest WPT test results for this feature

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