Customized built-in elements are HTML elements that extend built-in elements using the is attribute, to add new behaviors that you define.

Compatibility

• Chrome 67 Released on 2018-05-29
• Chrome Android 67 Released on 2018-05-31
• Edge 79 Released on 2020-01-15
• Firefox 63 Released on 2018-10-23
• Firefox for Android 63 Released on 2018-10-23
• Safari ❌ See webkit.org/b/182671
• Safari on iOS ❌ See webkit.org/b/182671

BCD data

• api.CustomElementRegistry.builtin_element_support
• html.global_attributes.is