Web platform features explorer - Scoped custom element registries

The CustomElementRegistry() constructor creates a new custom element registry that's separate from the global window.customElements registry. Creating more than one registry is useful for multiple custom elements that have the same tag name to coexist.

Status

Limited availability

MDN documentation

CustomElementRegistry: CustomElementRegistry() constructor
CustomElementRegistry: initialize() method

Specifications

HTML (#custom-elements-api), from HTML Workstream (WHATWG).
DOM (#element-custom-element-registry), from DOM Workstream (WHATWG).

Browser support

Chrome ❌ See issues.chromium.org/issues/40826514
Chrome Android ❌
Edge ❌
Firefox ❌ See bugzil.la/1874414
Firefox for Android ❌
Safari 26 Released on 2025-09-15
Safari on iOS 26 Released on 2025-09-15

Web Platform Tests (WPT)

View the latest WPT test results for this feature

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