Download Firefox Developer Edition 121.0b6

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

Updated: December 03, 2023

Size: 145 MB

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145 MB · December 03, 2023

Firefox%20121.0b6.dmg

Previous versions More »

138.0b8 April 18, 2025 141 MB 138.0b7 April 16, 2025 140 MB 138.0b6 April 13, 2025 141 MB 138.0b4 April 09, 2025 142 MB 138.0b2 April 04, 2025 142 MB 138.0b1 April 02, 2025 141 MB