Web platform features explorer - Form-associated custom elements

Web platform features explorer

Custom elements may act like built-in form elements, via the the attachInternals() method of HTMLElement and the ElementInternals API.

Status

Baseline Widely Available (since 2025-09-27)

MDN documentation

Specifications

HTML (#form-associated-custom-elements), from HTML Workstream (WHATWG).

Browser support

Chrome 77 Released on 2019-09-10
Chrome Android 77 Released on 2019-09-10
Edge 79 Released on 2020-01-15
Firefox 98 Released on 2022-03-08
Firefox for Android 98 Released on 2022-03-08
Safari 16.4 Released on 2023-03-27
Safari on iOS 16.4 Released on 2023-03-27

Developer signals

State of HTML 2025: features/all_features question
State of HTML 2024: web_components/web_components_features question
State of HTML 2024: web_components/web_component_features question
State of HTML 2024: features/all_features question
State of HTML 2023: web_components/web_components_main_features question
State of HTML 2023: features/all_features question

Interop

Included in Interop 2023

Web Platform Tests (WPT)

View the latest WPT test results for this feature

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