| Release Date | April 21, 2026 |
|---|---|
| Release Owner | Dianna Smith |
| Corresponding ESR releases | 140.10.0 |
| Nightly cycle length | 4 weeks |
| Beta cycle length | 4 weeks |
| 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. |
February 20 In 9.5 weeks |
Deadline to request accessibility engineering reviewAccessibility engineering review has been requested (using the |
February 20 In 9.5 weeks |
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. |
February 23 In 10 weeks |
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. |
March 6?
In 11.5 weeks |
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. |
March 6 In 11.5 weeks |
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. |
March 19 In 13.5 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. |
March 20 In 13.5 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. |
March 20 In 13.5 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 150 and the beginning of our Beta stabilization cycle. |
March 23 In 14 weeks |
Beta 1 Go to buildBuilt manually just after the merge. It ships on Tuesday. Uplift requests are open. |
March 23 In 14 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. |
March 24 In 14 weeks |
Beta 2First automated beta of the cycle. It is rolled out to 50% of our beta population. Build starts at 13:00 UTC. |
March 25 In 14.5 weeks |
Beta 3Beta rollout bumped to 100% provided stability is good. Build starts at 13:00 UTC. Stabilization work via uplifts. |
March 27 In 14.5 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. |
March 27 In 14.5 weeks |
Beta 4Build starts at 13:00 UTC. Stabilization work via uplifts. |
March 30 In 15 weeks |
Beta 5Build starts at 13:00 UTC. Stabilization work via uplifts. |
April 1 In 15.5 weeks |
Beta 6 Last early betaOn 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. |
April 3 In 15.5 weeks |
Beta 7Experimental features are no longer activated at compile time. Build starts at 13:00 UTC. Stabilization work via uplifts. |
April 6 In 16 weeks |
SUMO content localizationNew content on support.mozilla.org team is finalized, uploaded to the server and provided to our localization teams internationally. |
April 6 In 16 weeks |
Beta 8Last week of the beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
April 8 In 16.5 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. |
April 8 In 16.5 weeks |
Beta 9 Last beta uplifts (sec-approval request deadline)On a regular 4 weeks beta cycle, this is the last beta and thus the end of beta uplifts, including security bugs for this release ( |
April 10 In 16.5 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. |
April 13 In 17 weeks |
Release Candidate Release notes finalizedOur Release Candidate is shipped to all of our beta population. |
April 14 In 17 weeks |
Release day!We ship Firefox 150 at 14:00 UTC (6AM PST) at 25% rollout. |
April 21 In 18 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. |
April 28 In 19 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. |
May 5 In 20 weeks |
| Milestones | |
|---|---|
150.0 branch is createdThe |
April 10 |
150.0 release candidate is createdThe 150.0 release candidate is created based on the |
April 10 |
Preliminary QA sign off on 150.0QA gives a preliminary sign off on 150.0. 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. |
April 13 |
Final QA sign off on 150.0 Release notes readyQA gives its final sign off on 150.0. 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. |
April 14 |
150.0 sent to Apple StoreWe submit 150.0 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. |
April 14 |
150.1 branch is createdThe |
April 17 |
150.1 release candidate is createdThe 150.1 release candidate is created based on the |
April 17 |
150.0 is shipped150.0 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
April 20 |
Preliminary QA sign off on 150.1QA gives a preliminary sign off on 150.1. 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. |
April 20 |
Final QA sign off on 150.1 Release notes readyQA gives its final sign off on 150.1. 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. |
April 21 |
150.1 sent to Apple StoreWe submit 150.1 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. |
April 23 |
150.2 branch is createdThe |
April 24 |
150.2 release candidate is createdThe 150.2 release candidate is created based on the |
April 24 |
150.1 is shipped150.1 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
April 27 |
Preliminary QA sign off on 150.2QA gives a preliminary sign off on 150.2. 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. |
April 27 |
Final QA sign off on 150.2 Release notes readyQA gives its final sign off on 150.2. 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. |
April 28 |
150.2 sent to Apple StoreWe submit 150.2 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. |
April 30 |
150.3 branch is createdThe |
May 1 |
150.3 release candidate is createdThe 150.3 release candidate is created based on the |
May 1 |
150.2 is shipped150.2 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
May 4 |
Preliminary QA sign off on 150.3QA gives a preliminary sign off on 150.3. 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. |
May 4 |
Final QA sign off on 150.3 Release notes readyQA gives its final sign off on 150.3. 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. |
May 5 |
150.3 sent to Apple StoreWe submit 150.3 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. |
May 7 |
150.3 is shipped150.3 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
May 11 |