Firefox Developer Edition is the blazing fast browser that offers cutting edge developer tools and latest features like CSS Grid support and framework debugging

Experience cutting-edge browser features in pre-release versions: Firefox Developer Edition, Firefox Beta and Firefox Nightly. Download now!

Dec 5, 2016 · By using the Developer Edition, you gain access to tools and platform features at least 12 weeks before they reach the main Firefox release channel. Find out what's new in the Developer …

Looking for more than just Developer Tools? Check out the Firefox browser that is built specifically for developers and modern workflows.

Jan 23, 2026 · Tailored to meet the particular requirements of web developers, Firefox Developer Edition features a solid toolbox to help you test and optimize web applications.

Aug 18, 2025 · Our developer guide explains how to get Firefox source code, how to build it on Linux, macOS and Windows, how to find your way around, and how to contribute to the project.

Examine, edit, and debug HTML, CSS, and JavaScript on the desktop and on mobile. For the latest updates to the developer tools, download Firefox Developer Edition.

Jul 23, 2025 · Firefox Developer Edition is a special version of the Firefox browser designed specifically for web developers. It comes with additional tools, features, and customizations that are geared …

Jan 13, 2026 · Firefox Beta and Developer Edition Release Notes Release Notes tell you what’s new in Firefox. As always, we welcome your feedback. You can also file a bug in Bugzilla or see the system …

4 days ago · Mozilla Shows Off AI Browser Kill Switch for Firefox It launches with Firefox version 148 on Feb. 24, and you can keep everything, shut it off entirely, or cherry-pick the AI features you want to use.