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!

6 days ago · Mozilla Firefox is a popular and open-source web browser released by Mozilla Corporation. In past, Mozilla used to provide full offline installer of Firefox, so users didn’t need Internet …

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 …

Nov 12, 2022 · If you have a question about developing Firefox, and can't find the solution on Firefox Source Docs, you can try asking your question on Matrix at chat.mozilla.org in the Introduction channel.

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 12, 2026 · Firefox 147 open-source web browser is now available for download with support for Freedesktop.org's XDG Base Directory Specification.

6 days ago · Community Contributions With the release of Firefox 147, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 14 of whom were brand …

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.