Extension Workshop has the resources you need to learn how to develop, test, launch, and manage extensions for Firefox. Firefox extensions are built using the WebExtensions API, a Web-based framework that offers a powerful way to build extensions that can easily be ported to Chrome, Opera, and Edge.
Build secure extensions
More than ever, people are concerned for their privacy online. As an extension developer for Firefox, you can also build trust with your users by putting their safety and privacy first. Check out these security best practices for extension development.
WebExtensions API on MDN docs
Visit MDN web docs to learn how to build your first extension and look up reference documentation for the WebExtensions API.
The Add-ons Blog
Stay up-to-date with the latest information and announcements for the Firefox add-ons ecosystem.
Browse the Add-Ons directory
Extensions are like apps for Firefox. They add features to Firefox to make browsing faster, safer, or just plain fun.