Milestones and key data for Firefox 147

Release Date	January 13, 2026
Release Owner	Ryan VanderMeulen
Corresponding ESR releases	140.7.0 · 115.32.0^?
Nightly cycle length	4 weeks
Beta cycle length	5 weeks
Bugs fixed in nightly	1765
Uplifts in beta	134 (1 backout)
Uplifts in RC	2 (0 backouts)
Uplifts in dot releases	16 (0 backouts)
Total number of uplifts	152
Betas	9
Release Candidates	1
Dot releases	1
Release notes	General · Developer · Enterprise

Key Milestones
Nightly start	November 11
Beta start	December 9
147.0 ^{18% adoption}	January 13
147.0.1 ^{51% adoption} ^{100% rollout}	January 16
Planned 147.0.x ^{Desktop and Android}	January 27

Milestones
147.0 branch is created The `firefox-v147.0` branch is created from the `main` branch. `version.txt` is bumped to 147.1 on `main`. Any further code change for the 147.0 release now requires an uplift request.	December 29
147.0 release candidate is created The 147.0 release candidate is created based on the `firefox-v147.0` branch. This build might contain additional uplifts. Additionaly, the 146.3 release is tagged as shipped.	December 29
Preliminary QA sign off on 147.0 QA gives a preliminary sign off on 147.0. 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 31
Final QA sign off on 147.0 Release notes ready QA gives its final sign off on 147.0. 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.	January 8
147.0 sent to Apple Store We submit 147.0 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.	January 8
147.1 branch is created The `firefox-v147.1` branch is created from the `main` branch. `version.txt` is bumped to 147.2 on `main`. Any further code change for the 147.1 release now requires an uplift request.	January 9
147.1 release candidate is created The 147.1 release candidate is created based on the `firefox-v147.0` branch. This build might contain additional uplifts. Additionaly, the 147.0 release is tagged as shipped.	January 9
147.0 is shipped 147.0 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%.	January 12
Preliminary QA sign off on 147.1 QA gives a preliminary sign off on 147.1. 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.	January 12
Final QA sign off on 147.1 Release notes ready QA gives its final sign off on 147.1. 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.	January 13
147.1 sent to Apple Store We submit 147.1 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.	January 15
147.2 branch is created The `firefox-v147.2` branch is created from the `main` branch. `version.txt` is bumped to 147.3 on `main`. Any further code change for the 147.2 release now requires an uplift request.	January 16
147.2 release candidate is created The 147.2 release candidate is created based on the `firefox-v147.0` branch. This build might contain additional uplifts. Additionaly, the 147.1 release is tagged as shipped.	January 16
147.1 is shipped 147.1 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%.	January 19
Preliminary QA sign off on 147.2 QA gives a preliminary sign off on 147.2. 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.	January 19
Final QA sign off on 147.2 Release notes ready QA gives its final sign off on 147.2. 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.	January 20
147.2 sent to Apple Store We submit 147.2 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.	January 22
147.3 branch is created The `firefox-v147.3` branch is created from the `main` branch. `version.txt` is bumped to 147.4 on `main`. Any further code change for the 147.3 release now requires an uplift request.	January 23
147.3 release candidate is created The 147.3 release candidate is created based on the `firefox-v147.0` branch. This build might contain additional uplifts. Additionaly, the 147.2 release is tagged as shipped.	January 23
147.2 is shipped 147.2 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%.	January 26
Preliminary QA sign off on 147.3 QA gives a preliminary sign off on 147.3. 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.	January 26
Final QA sign off on 147.3 Release notes ready QA gives its final sign off on 147.3. 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.	January 27
147.3 sent to Apple Store We submit 147.3 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.	January 29
147.4 branch is created The `firefox-v147.4` branch is created from the `main` branch. `version.txt` is bumped to 147.5 on `main`. Any further code change for the 147.4 release now requires an uplift request.	January 30
147.4 release candidate is created The 147.4 release candidate is created based on the `firefox-v147.0` branch. This build might contain additional uplifts. Additionaly, the 147.3 release is tagged as shipped.	January 30
147.3 is shipped 147.3 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%.	February 2
Preliminary QA sign off on 147.4 QA gives a preliminary sign off on 147.4. 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.	February 2
Final QA sign off on 147.4 Release notes ready QA gives its final sign off on 147.4. 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.	February 3
147.4 sent to Apple Store We submit 147.4 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.	February 5
147.5 branch is created The `firefox-v147.5` branch is created from the `main` branch. `version.txt` is bumped to 148.0 on `main`. Any further code change for the 147.5 release now requires an uplift request.	February 6
147.5 release candidate is created The 147.5 release candidate is created based on the `firefox-v147.0` branch. This build might contain additional uplifts. Additionaly, the 147.4 release is tagged as shipped.	February 6
147.4 is shipped 147.4 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%.	February 9
Preliminary QA sign off on 147.5 QA gives a preliminary sign off on 147.5. 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.	February 9
Final QA sign off on 147.5 Release notes ready QA gives its final sign off on 147.5. 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.	February 10
147.5 sent to Apple Store We submit 147.5 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.	February 12
147.5 is shipped 147.5 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%.	February 16