Most browsers support Chrome extensions, but Firefox does not, it's not hard to create an extension for Firefox if I have the code of a Google extension; that's not a problem at all, as Firefox uses add-ons. However, other popular browsers like Edge, Brave, Opera, and Kiwi do support Chrome extensions because they are based on the Chromium engine.

What is the Chromium engine ? : the Chromium engine runs web browsers like Google Chrome, Microsoft Edge, and others; it is the fundamental code enabling browsers to execute extensions and display webpages. Though still compatible with Chrome extensions, other browsers may build on top of it and personalize it for their own use as it is open-source.