BASELINE NowYouCanUse.com
Widely Available Custom elements
id: form-associated-custom-elements

Form-associated custom elements

Custom elements may act like built-in form elements, via the attachInternals() method of HTMLElement and the ElementInternals API.
Baseline Status: Achieved Widely Available on Sep 27, 2025 (Cross-browser Newly Available since Mar 27, 2023).
Desktop Browser Engine Support
Google Chrome
77
Supported
Mozilla Firefox
98
Supported
Apple Safari
16.4
Supported
Microsoft Edge
79
Supported
Mobile Browser Engine Support
Chrome Android
77
Firefox Android
98
Safari iOS
16.4
Specifications and References
Specification ↗ Feature XML ↗
MDN Browser Compat Data Keys:
api.ElementInternals ↗ api.ElementInternals.checkValidity ↗ api.ElementInternals.form ↗ api.ElementInternals.labels ↗ api.ElementInternals.reportValidity ↗ api.ElementInternals.setFormValue ↗ api.ElementInternals.setValidity ↗ api.ElementInternals.validationMessage ↗ api.ElementInternals.validity ↗ api.ElementInternals.willValidate ↗ api.HTMLElement.attachInternals ↗