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.

To simply take a look at the Firefox source code, you do not need to download it. You can look at the source directly with your web browser using Searchfox (start at …

The new Firefox DevTools are powerful, flexible, and best of all, hackable. This includes a best-in-class JavaScript debugger, which can target multiple browsers and is built in React and Redux.

Generally, most globals should be automatically set up. If you think you are missing some globals, and they are in one of the defined sections, you can generally add the file here. However, …

Mozilla has 2499 repositories available. Follow their code on GitHub.

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May 13, 2025 · The Mozilla Firefox source code is now officially available on GitHub as they work to transition from their hg.mozilla.org servers.

May 15, 2025 · The official GitHub repository for Firefox , a web browser developed by the Mozilla Foundation, has been launched.

You can explore the directory structure, review build projects (view the components that are generated), source code (view the functions that are declared or implemented)...

Mozilla-Firefox has 10 repositories available. Follow their code on GitHub.