| Release Date | February 9, 2027 |
|---|---|
| Release Owner | Pascal Chevrel |
| Corresponding ESR releases | 153.12.0 · 115.50.0? |
| Nightly cycle length | 2 weeks |
| Beta cycle length | 2 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. |
December 31 In 10 weeks |
Deadline to request accessibility engineering reviewAccessibility engineering review has been requested (using the |
January 7 In 11 weeks |
Nightly startsThe first day of the cycle is Merge Day. After merging firefox-main to the beta branch, we bump the nightly version number on firefox-main and a new development cycle starts for Firefox. A new Firefox Nightly is shipped every 12 hours. |
January 7 In 11 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. |
January 14 In 12 weeks |
QA Test Case reviewThe 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. |
January 15 In 12 weeks |
Strings hand-off to engineeringFinal strings are handed off to Engineering to ensure they are landed before localization begins. |
January 18 In 12.5 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. |
January 20 In 13 weeks |
Nightly QA sign-offQA signs off on new features in Nightly by sharing individual test reports with their quality assessment and reasoning. |
January 20 In 13 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. |
January 21 In 13 weeks |
Merge dayThis is the day in the release cycle when we merge firefox-main into the beta branch. This is the end of the development cycle for Firefox 165 and the beginning of our Beta stabilization cycle. |
January 21 In 13 weeks |
Beta 1First beta of the cycle, rolled out to our beta population. Build starts at 13:00 UTC. Stabilization work via uplifts. |
January 25 In 13.5 weeks |
Beta 2First automated beta of the cycle. It is rolled out to 100% of our beta population. Build starts at 13:00 UTC. |
January 27 In 14 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 before release day. |
January 28 In 14 weeks |
Beta 3Build starts at 13:00 UTC. Stabilization work via uplifts. |
January 29 In 14 weeks |
Beta 4Build starts at 13:00 UTC. Stabilization work via uplifts. |
February 1 In 14.5 weeks |
Deadline to request security bug uplifts ESR patches must be readyDeadline for security bugs uplift requests ( |
February 2 In 14.5 weeks |
Beta 5 Last beta upliftsLast beta of the cycle and thus the end of beta uplifts. Build starts at 13:00 UTC. |
February 3 In 15 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. |
February 4 In 15 weeks |
Release Candidate Ready for QAThis 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 4 In 15 weeks |
Release day!Firefox 165 ships at 14:00 UTC (6 AM PT) with an initial 25% rollout. |
February 9 In 15.5 weeks |
Dot release 1Scheduled for one week after launch, this Desktop and/or Android release targets critical quality fixes and selective feature uplifts. The deadline for uplift requests is EOD on the Friday prior to go-live. Should emergency dot releases ship earlier and resolve pending issues, the Release Management team will determine if this scheduled milestone remains necessary. |
February 16 In 16.5 weeks |
| Milestones | |
|---|---|
165.0 branch is createdThe |
January 29 |
165.0 release candidate is createdThe 165.0 release candidate is created based on the |
January 29 |
Preliminary QA sign off on 165.0QA gives a preliminary sign off on 165.0. 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 1 |
Final QA sign off on 165.0 Release notes readyQA gives its final sign off on 165.0. 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 2 |
165.0 sent to Apple StoreWe submit 165.0 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 2 |
165.1 branch is createdThe |
February 5 |
165.1 release candidate is createdThe 165.1 release candidate is created based on the |
February 5 |
165.0 is shipped165.0 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
February 8 |
Preliminary QA sign off on 165.1QA gives a preliminary sign off on 165.1. 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 8 |
Final QA sign off on 165.1 Release notes readyQA gives its final sign off on 165.1. 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 9 |
165.1 sent to Apple StoreWe submit 165.1 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 11 |
165.1 is shipped165.1 is shipped on the Apple Store at 3:00 AM UTC with a phased 7 days rollout: |
February 15 |