| Release Date | February 24, 2026 |
|---|---|
| Release Owner | Donal Meehan |
| Corresponding ESR releases | 140.8.0 · 115.33.0? |
| Latest BuildID | 20251208220232 |
| Nightly cycle length | 5 weeks |
| Beta cycle length | 6 weeks |
| Release notes | Nightly notes |
| Milestones | |
|---|---|
Deadline to request manual QAQA has been informed (via a Jira ticket) about features that require manual testing during the nightly and/or beta cycle. |
December 5 4 days ago |
Deadline to request accessibility engineering reviewAccessibility engineering review has been requested (using the |
December 5 4 days ago |
Nightly startsThe first day of the cycle is Merge Day. After merging mozilla-central to mozilla-beta, we bump the nightly version number on mozilla-central and a new development cycle starts for Firefox. A new Firefox Nightly is shipped every 12 hours. |
December 8 Yesterday |
Build ready for QAFeatures with a QA request are ready for testing to assess feature quality and provide a formal test report by the end of Week 2 of the nightly cycle. |
December 19 In 7 working days |
QA Test Plan approval dueThe QA team appreciates an earlier sign-off from the project teams. The approval milestone will be the final deadline for any feature Test Plan sign-offs. No feedback/sign-off on QAs Feature Test Plan could result in misalignment on testing scope, incomplete test coverage and invalid bugs. |
December 19 In 7 working days |
Soft Code Freeze starts Draft beta release notesWe are nearing the end of the nightly cycle. Don't land new untested features. Risky changes should be avoided after 8:00 AM UTC until after the nightly version bump on Merge Day. |
January 8 In 4 weeks |
String Freeze startsIn order to ensure that our localizers have adequate time to translate strings, please make sure that all string changes have landed by end of day. |
January 9 In 4 weeks |
QA pre-merge regression testing doneQA assess build readiness for shipping to Beta by running a set of Regression test cases and shares a test report. |
January 9 In 4 weeks |
Merge dayThis is the day in the release cycle when we merge mozilla-central into mozilla-beta. This is the end of the development cycle for Firefox 148 and the beginning of our Beta stabilization cycle. |
January 12 In 4.5 weeks |
Beta 1 Go to buildBuilt manually just after the merge. It ships on Tuesday. Uplift requests are open. |
January 12 In 4.5 weeks |
Beta 1Rolled out to 25% of our beta population. Some experimental features are still activated to watch their behavior on a wider population. These experimental features will be deactivated mid-cycle. |
January 13 In 4.5 weeks |
Beta 2First automated beta of the cycle. It is rolled out to 50% of our beta population. Build starts at 13:00 UTC. |
January 14 In 5 weeks |
Beta 3Beta rollout bumped to 100% provided stability is good. Build starts at 13:00 UTC. Stabilization work via uplifts. |
January 16 In 5 weeks |
SUMO content creationUser affecting changes were identified and provided to the support.mozilla.org team. The support content for this release can now be created and will be translated before RC week. |
January 16 In 5 weeks |
Beta 4Build starts at 13:00 UTC. Stabilization work via uplifts. |
January 19 In 5.5 weeks |
Beta 5Build starts at 13:00 UTC. Stabilization work via uplifts. |
January 21 In 6 weeks |
Beta 6On a regular 4 weeks beta cycle, Beta 6 is the last beta with experimental features still activated. Build starts at 13:00 UTC. Stabilization work via uplifts. |
January 23 In 6 weeks |
Beta 7Experimental features are no longer activated at compile time. Build starts at 13:00 UTC. Stabilization work via uplifts. |
January 26 In 6.5 weeks |
SUMO content localizationNew content on support.mozilla.org team is finalized, uploaded to the server and provided to our localization teams internationally. |
January 26 In 6.5 weeks |
Beta 8Last week of the beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
January 28 In 7 weeks |
Pre-release QA sign-offA week before the final sign-off, QA shares preliminary test reports for each feature riding the train. This pre-release sign-off can be Green, Yellow or Red. |
January 28 In 7 weeks |
Beta 9 Last early betaOn a regular 4 weeks beta cycle, this is the last beta and thus the end of beta uplifts, including security bugs for this release ( |
January 30 In 7 weeks |
Beta 10Extra beta usually due to a longer beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
February 2 In 7.5 weeks |
Beta 11Extra beta usually due to a longer beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
February 4 In 8 weeks |
Beta 12Extra beta usually due to a longer beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
February 6 In 8 weeks |
Beta 13Extra beta usually due to a longer beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
February 9 In 8.5 weeks |
Beta 14Extra beta usually due to a longer beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
February 11 In 9 weeks |
Beta 15 Last beta uplifts (sec-approval request deadline)Extra beta usually due to a longer beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
February 13 In 9 weeks |
Release Candidate Go to buildWe merge our mozilla-beta repository to mozilla-release and close mozilla-beta until the next merge day. We then build our Release Candidate from mozilla-release. This is the build we intend to ship a week later unless we need to build another Release Candidate to fix a major quality or business critical issue. |
February 16 In 9.5 weeks |
Release Candidate Release notes finalizedOur Release Candidate is shipped to all of our beta population. |
February 17 In 9.5 weeks |
Release day!We ship Firefox 148 at 14:00 UTC (6AM PST) at 25% rollout. |
February 24 In 10.5 weeks |
Potential Android dot releaseOne week after the release, we evaluate shipping an Android dot release to address identified issues. We can also enable new features on a on a case by case basis if they are suitable for uplift. The decision on shipping or not this dot release for Android is on the release management team. |
March 3 In 11.5 weeks |
Planned dot releaseTwo weeks after the release, we ship a desktop and/or an Android dot release to address identified quality issues with safe fixes ready. We can also enable new features on a on a case by case basis if they are suitable for uplift. We may have to ship other dot releases before that date. If this is the case and post-release quality issues are already fixed and shipped, the decision on shipping or not the planned dot release is on the release management team. |
March 10 In 12.5 weeks |
| Milestones | |
|---|---|
148.0 branch is createdThe |
February 13 |
148.0 release candidate is createdThe 148.0 release candidate is created based on the |
February 13 |
Preliminary QA sign off on 148.0QA gives a preliminary sign off on 148.0. 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. |
February 16 |
Final QA sign off on 148.0 Release notes readyQA gives its final sign off on 148.0. 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. |
February 17 |
148.0 sent to Apple StoreWe submit 148.0 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. |
February 19 |
148.1 branch is createdThe |
February 20 |
148.1 release candidate is createdThe 148.1 release candidate is created based on the |
February 20 |
148.0 is shipped148.0 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
February 23 |
Preliminary QA sign off on 148.1QA gives a preliminary sign off on 148.1. 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. |
February 23 |
Final QA sign off on 148.1 Release notes readyQA gives its final sign off on 148.1. 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. |
February 24 |
148.1 sent to Apple StoreWe submit 148.1 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. |
February 26 |
148.2 branch is createdThe |
February 27 |
148.2 release candidate is createdThe 148.2 release candidate is created based on the |
February 27 |
148.1 is shipped148.1 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
March 2 |
Preliminary QA sign off on 148.2QA gives a preliminary sign off on 148.2. 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. |
March 2 |
Final QA sign off on 148.2 Release notes readyQA gives its final sign off on 148.2. 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. |
March 3 |
148.2 sent to Apple StoreWe submit 148.2 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. |
March 5 |
148.3 branch is createdThe |
March 5 |
148.3 release candidate is createdThe 148.3 release candidate is created based on the |
March 5 |
148.2 is shipped148.2 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
March 9 |
Preliminary QA sign off on 148.3QA gives a preliminary sign off on 148.3. 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. |
March 9 |
Final QA sign off on 148.3 Release notes readyQA gives its final sign off on 148.3. 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. |
March 10 |
148.3 sent to Apple StoreWe submit 148.3 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. |
March 12 |
148.3 is shipped148.3 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
March 16 |