Milestones and key data for Firefox 146

Release Date	December 9, 2025
Release Owner	Dianna Smith
Corresponding ESR releases	140.6.0 · 115.31.0^?
Nightly cycle length	4 weeks
Beta cycle length	4 weeks
Bugs fixed in nightly	1943
Uplifts in beta	137 (0 backouts)
Uplifts in RC	4 (0 backouts)
Uplifts in dot releases	0 (0 backouts)
Total number of uplifts	141
Betas	9
Release Candidates	2
Dot releases	0
Release notes	General · Developer · Enterprise

Key Milestones
Nightly start	October 14
Beta start	November 11
146.0 ^{65% adoption - 100% rollout}	December 9
Potential Android 146.0.x	December 16
Planned 146.0.x ^{Desktop and Android}	December 18

Milestones
146.0 branch is created The `firefox-v146.0` branch is created from the `main` branch. `version.txt` is bumped to 146.1 on `main`. Any further code change for the 146.0 release now requires an uplift request.	November 28
146.0 release candidate is created The 146.0 release candidate is created based on the `firefox-v146.0` branch. This build might contain additional uplifts. Additionaly, the 145.3 release is tagged as shipped.	November 28
Preliminary QA sign off on 146.0 QA gives a preliminary sign off on 146.0. If it is green, we push the build to the External Beta Testers group. Otherwise, the dev team fixes the issues reported by QA, uplift them to the release branch and we build another Release Candidate.	December 1
Final QA sign off on 146.0 Release notes ready QA gives its final sign off on 146.0. If the sign off is red, the dev team fixes the issues reported by QA, uplift them to the release branch and we build another Release Candidate.	December 2
146.0 sent to Apple Store We submit 146.0 for review to the Apple Store. If we don`t have a working build by the end of the day, we may not ship this week.	December 2
146.1 branch is created The `firefox-v146.1` branch is created from the `main` branch. `version.txt` is bumped to 147.0 on `main`. Any further code change for the 146.1 release now requires an uplift request.	December 5
146.1 release candidate is created The 146.1 release candidate is created based on the `firefox-v146.0` branch. This build might contain additional uplifts. Additionaly, the 146.0 release is tagged as shipped.	December 5
146.0 is shipped 146.0 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: Monday: 1%, Tuesday: 2%, Wednesday: 5%, Thursday: 10%, Friday: 20%, Saturday: 50%, Sunday: 100%.	December 8
Preliminary QA sign off on 146.1 QA gives a preliminary sign off on 146.1. If it is green, we push the build to the External Beta Testers group. Otherwise, the dev team fixes the issues reported by QA, uplift them to the release branch and we build another Release Candidate.	December 8
Final QA sign off on 146.1 Release notes ready QA gives its final sign off on 146.1. If the sign off is red, the dev team fixes the issues reported by QA, uplift them to the release branch and we build another Release Candidate.	December 9
146.1 sent to Apple Store We submit 146.1 for review to the Apple Store. If we don`t have a working build by the end of the day, we may not ship this week.	December 11
146.1 is shipped 146.1 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: Monday: 1%, Tuesday: 2%, Wednesday: 5%, Thursday: 10%, Friday: 20%, Saturday: 50%, Sunday: 100%.	December 15