| Release Date | August 18, 2026 |
|---|---|
| Release Owner | Dianna Smith |
| Corresponding ESR releases | 153.1.0 · 140.14.0 |
| Nightly cycle length | 5 weeks |
| Beta cycle length | 4 weeks |
| Milestones | |
|---|---|
Deadline to request manual QAQA has been informed via a Jira ticket (Functional, Nimbus/Remote delivery or Embedded QA) about features needing manual testing — more on how to file a Jira ticket here. Test Plans and Cases also require the technical documentation, which should be attached to the ticket. |
June 12 In 15 weeks |
Deadline to request accessibility engineering reviewAccessibility engineering review has been requested (using the |
June 12 In 15 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. |
June 15 In 15.5 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. |
July 3 In 18 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. |
July 3 In 18 weeks |
Draft beta release notesA draft document was created and shared internally with stakeholders to prepare our final release notes for general availability. This document initially contains a copy of our public beta release notes shipping the week after and will be enriched during the beta cycle with media and final copy. |
July 15 In 19.5 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. |
July 17 In 20 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. |
July 17 In 20 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 154 and the beginning of our Beta stabilization cycle. |
July 20 In 20.5 weeks |
Beta 1Rolled out to 50% 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. |
July 22 In 20.5 weeks |
Beta 2First automated beta of the cycle. It is rolled out to 100% of our beta population. Build starts at 13:00 UTC. |
July 24 In 21 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. |
July 24 In 21 weeks |
Beta 3Build starts at 13:00 UTC. Stabilization work via uplifts. |
July 27 In 21.5 weeks |
Beta 4Build starts at 13:00 UTC. Stabilization work via uplifts. |
July 29 In 21.5 weeks |
Beta 5 Last early betaOn a regular 4 weeks beta cycle, Beta 5 is the last beta with experimental features still activated. Build starts at 13:00 UTC. Stabilization work via uplifts. |
July 31 In 22 weeks |
Beta 6Build starts at 13:00 UTC. Stabilization work via uplifts. Experimental features are no longer activated at compile time. |
August 3 In 22.5 weeks |
SUMO content localizationNew content on support.mozilla.org team is finalized, uploaded to the server and provided to our localization teams internationally. |
August 3 In 22.5 weeks |
Beta 7Build starts at 13:00 UTC. Stabilization work via uplifts. |
August 5 In 22.5 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. |
August 5 In 22.5 weeks |
Beta 8 Security bugs uplift request deadlineBuild starts at 13:00 UTC. Stabilization work via uplifts. |
August 7 In 23 weeks |
Beta 9Build starts at 13:00 UTC. Stabilization work via uplifts. |
August 10 In 23.5 weeks |
Release notes submission deadlineAll release notes for Firefox were added to the draft document or communicated directly with the release manager. Illustrations such as screenshots and videos were provided. Final Release release notes are created by the release manager on firefox.com. |
August 11 In 23.5 weeks |
Beta 10 Last beta upliftsOn a regular 4 weeks beta cycle, this is the last beta and thus the end of beta uplifts. Build starts at 13:00 UTC. |
August 12 In 23.5 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. |
August 12 In 23.5 weeks |
Release Candidate Release notes finalizedOur Release Candidate is built and available for testing. |
August 12 In 23.5 weeks |
Release day!We ship Firefox 154 at 14:00 UTC (6AM PST) at 25% rollout. |
August 18 In 24.5 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. |
August 25 In 25.5 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. |
September 1 In 26.5 weeks |
| Milestones | |
|---|---|
154.0 branch is createdThe |
August 7 |
154.0 release candidate is createdThe 154.0 release candidate is created based on the |
August 7 |
Preliminary QA sign off on 154.0QA gives a preliminary sign off on 154.0. 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. |
August 10 |
Final QA sign off on 154.0 Release notes readyQA gives its final sign off on 154.0. 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. |
August 11 |
154.0 sent to Apple StoreWe submit 154.0 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. |
August 11 |
154.1 branch is createdThe |
August 14 |
154.1 release candidate is createdThe 154.1 release candidate is created based on the |
August 14 |
154.0 is shipped154.0 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
August 17 |
Preliminary QA sign off on 154.1QA gives a preliminary sign off on 154.1. 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. |
August 17 |
Final QA sign off on 154.1 Release notes readyQA gives its final sign off on 154.1. 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. |
August 18 |
154.1 sent to Apple StoreWe submit 154.1 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. |
August 20 |
154.2 branch is createdThe |
August 21 |
154.2 release candidate is createdThe 154.2 release candidate is created based on the |
August 21 |
154.1 is shipped154.1 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
August 24 |
Preliminary QA sign off on 154.2QA gives a preliminary sign off on 154.2. 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. |
August 24 |
Final QA sign off on 154.2 Release notes readyQA gives its final sign off on 154.2. 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. |
August 25 |
154.2 sent to Apple StoreWe submit 154.2 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. |
August 27 |
154.3 branch is createdThe |
August 27 |
154.3 release candidate is createdThe 154.3 release candidate is created based on the |
August 27 |
154.2 is shipped154.2 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
August 31 |
Preliminary QA sign off on 154.3QA gives a preliminary sign off on 154.3. 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. |
August 31 |
Final QA sign off on 154.3 Release notes readyQA gives its final sign off on 154.3. 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. |
September 1 |
154.3 sent to Apple StoreWe submit 154.3 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. |
September 3 |
154.3 is shipped154.3 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
September 7 |