Download Firefox Developer Edition 143.0b9

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

Updated: September 07, 2025

Size: 149 MB

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149 MB · September 07, 2025

Firefox%20143.0b9.dmg

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144.0b2 September 19, 2025 152 MB 144.0b1 September 17, 2025 152 MB 143.0b9 September 07, 2025 149 MB 143.0b8 September 05, 2025 149 MB 143.0b7 September 03, 2025 149 MB 143.0b6 August 31, 2025 150 MB