Use this API to register content scripts. Registering a content script instructs the browser to insert the given content scripts into pages that match the given URL patterns.

This API is very similar to the "content_scripts" manifest.json key, except that with  "content_scripts" , the set of content scripts and associated patterns is fixed at install time. With the contentScripts API, an extension can register and unregister scripts at runtime.

To use the API, call contentScripts.register() passing in an object defining the scripts to register, the URL patterns, and other options. This returns a Promise that is resolved with a contentScripts.RegisteredContentScript object. The RegisteredContentScript object represents the scripts that were registered in the register() call. It defines an unregister() method that you can use to unregister the content scripts.

There is no contentScripts API permission, but an extension must have the appropriate host permissions for any patterns it passes to register().



An object of this type is returned by the contentScripts.register() function. It represents the content scripts that were registered by that call, and can be used to unregister the content script.


Registers the given content scripts.

Browser compatibility

ChromeEdgeFirefoxFirefox for AndroidOpera
RegisteredContentScript No No5959 No
RegisteredContentScript.unregister No No5959 No
register No No5959 No


Document Tags and Contributors

 Contributors to this page: wbamberg
 Last updated by: wbamberg,