| Release Date | October 13, 2026 |
|---|---|
| Release Owner | Donal Meehan |
| Corresponding ESR releases | 153.3.0 |
| 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. |
August 14 In 34.5 weeks |
Deadline to request accessibility engineering reviewAccessibility engineering review has been requested (using the |
August 14 In 34.5 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. |
August 17 In 35 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. |
August 28?
In 36.5 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. |
August 28 In 36.5 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. |
September 10 In 38.5 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. |
September 11 In 38.5 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. |
September 11 In 38.5 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 156 and the beginning of our Beta stabilization cycle. |
September 14 In 39 weeks |
Beta 1 Go to buildBuilt manually just after the merge. It ships on Tuesday. Uplift requests are open. |
September 14 In 39 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. |
September 15 In 39 weeks |
Beta 2First automated beta of the cycle. It is rolled out to 50% of our beta population. Build starts at 13:00 UTC. |
September 16 In 39.5 weeks |
Beta 3Beta rollout bumped to 100% provided stability is good. Build starts at 13:00 UTC. Stabilization work via uplifts. |
September 18 In 39.5 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. |
September 18 In 39.5 weeks |
Beta 4Build starts at 13:00 UTC. Stabilization work via uplifts. |
September 21 In 40 weeks |
Beta 5Build starts at 13:00 UTC. Stabilization work via uplifts. |
September 23 In 40.5 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. |
September 25 In 40.5 weeks |
Beta 7Experimental features are no longer activated at compile time. Build starts at 13:00 UTC. Stabilization work via uplifts. |
September 28 In 41 weeks |
SUMO content localizationNew content on support.mozilla.org team is finalized, uploaded to the server and provided to our localization teams internationally. |
September 28 In 41 weeks |
Beta 8Last week of the beta cycle. Build starts at 13:00 UTC. Stabilization work via uplifts. |
September 30 In 41.5 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. |
September 30 In 41.5 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 ( |
October 2 In 41.5 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. |
October 5 In 42 weeks |
Release Candidate Release notes finalizedOur Release Candidate is shipped to all of our beta population. |
October 6 In 42 weeks |
Release day!We ship Firefox 156 at 14:00 UTC (6AM PST) at 25% rollout. |
October 13 In 43 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. |
October 20 In 44 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. |
October 27 In 45 weeks |
| Milestones | |
|---|---|
156.0 branch is createdThe |
October 2 |
156.0 release candidate is createdThe 156.0 release candidate is created based on the |
October 2 |
Preliminary QA sign off on 156.0QA gives a preliminary sign off on 156.0. 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. |
October 5 |
Final QA sign off on 156.0 Release notes readyQA gives its final sign off on 156.0. 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. |
October 6 |
156.0 sent to Apple StoreWe submit 156.0 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. |
October 6 |
156.1 branch is createdThe |
October 9 |
156.1 release candidate is createdThe 156.1 release candidate is created based on the |
October 9 |
156.0 is shipped156.0 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
October 12 |
Preliminary QA sign off on 156.1QA gives a preliminary sign off on 156.1. 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. |
October 12 |
Final QA sign off on 156.1 Release notes readyQA gives its final sign off on 156.1. 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. |
October 13 |
156.1 sent to Apple StoreWe submit 156.1 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. |
October 15 |
156.2 branch is createdThe |
October 16 |
156.2 release candidate is createdThe 156.2 release candidate is created based on the |
October 16 |
156.1 is shipped156.1 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
October 19 |
Preliminary QA sign off on 156.2QA gives a preliminary sign off on 156.2. 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. |
October 19 |
Final QA sign off on 156.2 Release notes readyQA gives its final sign off on 156.2. 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. |
October 20 |
156.2 sent to Apple StoreWe submit 156.2 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. |
October 22 |
156.3 branch is createdThe |
October 22 |
156.3 release candidate is createdThe 156.3 release candidate is created based on the |
October 22 |
156.2 is shipped156.2 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
October 26 |
Preliminary QA sign off on 156.3QA gives a preliminary sign off on 156.3. 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. |
October 26 |
Final QA sign off on 156.3 Release notes readyQA gives its final sign off on 156.3. 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. |
October 27 |
156.3 sent to Apple StoreWe submit 156.3 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. |
October 29 |
156.3 is shipped156.3 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
November 2 |