Download Firefox Developer Edition 139.0b6

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

Updated: May 11, 2025

Size: 143 MB

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143 MB · May 11, 2025

Firefox%20139.0b6.dmg

Previous versions More »

139.0b7 May 14, 2025 142 MB 139.0b6 May 11, 2025 143 MB 139.0b5 May 09, 2025 143 MB 139.0b4 May 07, 2025 143 MB 139.0b3 May 04, 2025 143 MB 139.0b2 May 02, 2025 143 MB