Updated 8 Sep 2026: Chrome's side of the two-week cadence has now entered production: Chrome 153 reached Early Stable for a small percentage of desktop and Android users on September 3, ahead of the planned September 8 broad Stable cutover. Firefox 155 had already shipped September 1.
Key details
- Firefox 155 shipped September 1, 2026 as Mozilla’s first major release on the two-week cadence.
- Chrome 153 reached a small percentage of desktop and Android users through Early Stable on September 3, 2026.
- Google still identifies September 8 as the broad Stable cutover for Chrome’s two-week cadence.
- Chrome Beta and Stable move to two-week releases; Chrome Dev and Canary do not change.
- Chrome Extended Stable remains on an eight-week cycle.
- Mozilla says the regular Firefox release channel will continue with a new major version every two weeks after Firefox 155.
What builders should take away
- Add Chrome Beta/Early Stable and Firefox Beta to CI for browser-dependent production flows rather than waiting for broad Stable releases.
- Treat September 1 and September 3 as the operational start of the new Firefox and Chrome release trains, not merely the previously published calendar dates.
- Use rolling compatibility windows rather than assuming a major browser version represents roughly a month of stability.
- For enterprise customers, record whether support targets Chrome Stable, Chrome Extended Stable, Firefox Release or Firefox ESR, because the cadence differs materially by channel.
- Audit browser extensions and version-gated web features for automation or documentation that assumes four-week major releases.
What changed
Google and Mozilla are both moving their mainstream browser release trains from roughly four-week to two-week major releases, and both transitions have now reached production. Firefox 155 shipped September 1, 2026 as Mozilla’s first major release on the two-week cadence. Google then released Chrome 153.0.8010.27/.28 to a small percentage of desktop users and Chrome 153.0.8010.27 to a small percentage of Android users on September 3 as Early Stable builds, ahead of the planned September 8 broad Stable cutover. Chrome Beta and Stable move to two-week cycles across desktop and mobile, while Chrome Dev and Canary remain unchanged and Extended Stable stays on its eight-week schedule.
Why it matters
The cadence shift is now observable in real release operations rather than a future planning assumption. Major browser-version boundaries are arriving twice as often, giving extension developers, QA teams and web applications less calendar time for compatibility testing, documentation and enterprise rollout decisions. Chrome’s Early Stable staging also means the next major version can already be present on a minority of real-user devices before the headline Stable date, strengthening the case for continuous beta and staged-release testing rather than date-based validation alone.
Firefox’s two-week cadence is live
Firefox 155 shipped September 1, 2026 as Mozilla’s first major release on the new cadence, two weeks earlier than its former September 15 plan. Mozilla says the regular Firefox release channel will continue with a new major version every two weeks.
Chrome 153 entered Early Stable before the September 8 cutover
Google’s Chrome Releases feed shows Chrome 153.0.8010.27/.28 reaching a small percentage of Windows desktop users on September 3, with Mac following, and Chrome 153.0.8010.27 reaching a small percentage of Android users the same day. Google still identifies September 8 as the start of the new broad Stable cadence.
Enterprise channels retain slower options
Chrome Extended Stable remains on an eight-week cycle. Firefox ESR remains a distinct enterprise-support channel even as the standard Firefox release channel accelerates. Organizations should document which channel they certify rather than treating a browser name and major version as sufficient deployment policy.
Testing needs to become continuous
Teams that begin compatibility work only after broad Stable release have less time before another major version follows, and Early Stable means some users may see the next major version before the headline release date. High-value flows should run against Chrome Beta/Early Stable and Firefox Beta continuously, with extension APIs, authentication, payments, browser security changes and version-sensitive integrations receiving explicit coverage.
What to watch next
- Whether Chrome 153 completes its broad September 8 Stable rollout on schedule and whether the first two-week Chrome cycle exposes unusual regression/support load.
- How quickly enterprise tooling and browser-testing services update their version matrices.
- Whether Firefox ESR or Chrome Extended Stable policies change as standard-channel versions advance more rapidly.
- Whether Chromium-based browsers other than Chrome adopt Google’s exact two-week stable schedule.
Still unclear
- A faster major-version cadence does not necessarily mean twice as many features; both vendors say the intent is smaller, more frequent release trains.
- Emergency dot releases can still occur between scheduled major releases.
- Chromium-derived browsers and enterprise-managed channels may use schedules different from mainstream Chrome Stable.
- Chrome 153 was in Early Stable for a small percentage of users from September 3; the broad Stable rollout remained scheduled for September 8 at research time.
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