Download Firefox Developer Edition 140.0b5

Get the latest features, fast performance, and the development tools!

Updated: June 07, 2025

Size: 144 MB

Download

144 MB · June 07, 2025

Firefox%20140.0b4.dmg

Previous versions More »

142.0b3 July 27, 2025 149 MB 142.0b2 July 24, 2025 149 MB 142.0b1 July 23, 2025 149 MB 141.0b9 July 13, 2025 147 MB 141.0b8 July 11, 2025 147 MB 141.0b7 July 09, 2025 148 MB