# Chrome and Firefox are moving major releases to two-week cycles

Chrome and Firefox are both halving their major-release cadence, tightening the window for compatibility testing while keeping important exceptions such as Chrome Extended Stable.

Chrome starts a two-week stable cadence with Chrome 153 in September 2026, while Firefox begins its transition with Firefox 155 Beta. Web teams should expect faster browser-version turnover and adjust CI, beta testing and enterprise support assumptions accordingly.

- Status: Active
- Published: 2026-08-18T21:46:53+12:00
- Updated: 2026-08-18T21:46:53+12:00
- Categories: Web Development, Browsers & Web Standards
- Tags: browser releases, Chrome, Extended Stable, Firefox, testing, web compatibility
- Canonical HTML: https://beyondthe.news/dossiers/chrome-firefox-two-week-release-cycles

## What changed

Google announced that Chrome will move from a four-week to a two-week beta and stable release cycle starting with Chrome 153, whose stable release is scheduled for September 8, 2026. Mozilla is likewise moving Firefox Desktop and Android from four-week to two-week cycles, beginning with Firefox 155 Beta and then making Nightly, Beta and Release periods two weeks each.

## Why it matters

Browser-version assumptions age twice as quickly. Web applications, extension developers, QA teams and vendors that certify support by major version will have less calendar time to detect regressions, validate new web-platform behavior and update compatibility documentation.

## Chrome changes stable and beta, not every channel

Chrome's new cadence applies across Desktop, Android and iOS for beta and stable releases. Dev and Canary remain unchanged. Google also says Extended Stable will continue on its existing eight-week cycle, preserving a slower enterprise option.

## Firefox is changing the full train

Mozilla says Firefox 155 Beta starts the transition, after which Nightly, Beta and Release periods each become two weeks. The localization window also compresses, illustrating that the release-process change affects downstream contributors as well as browser users.

## Testing needs to become more continuous

Teams that wait for stable releases to begin compatibility testing will have less time to react before the next major version. Running important suites against beta channels and tracking browser-roadmap changes becomes more valuable, especially for extensions and APIs with version-specific behavior.

## Key details

- Chrome's two-week stable cadence begins with Chrome 153, scheduled for September 8, 2026.
- Chrome beta and stable will both ship every two weeks.
- Chrome Dev and Canary do not change.
- Chrome Extended Stable remains on an eight-week cycle.
- Firefox Desktop and Android are moving from four-week to two-week releases.
- Firefox's transition begins with Firefox 155 Beta; Nightly, Beta and Release periods then become two weeks.

## Builder takeaways

- Add Chrome Beta and Firefox Beta to CI for high-value browser-dependent flows instead of relying only on current stable versions.
- Replace support policies tied to long-lived major versions with rolling compatibility windows where possible.
- If you serve enterprise customers, distinguish Chrome Stable from Extended Stable in support documentation and incident triage.
- Audit browser-extension release processes and web-platform feature flags for assumptions that a major version lasts about a month.

## What to watch

- Whether the faster cadence increases regression frequency or instead reduces per-release change size as vendors expect.
- How managed-device and enterprise browser policies adapt to the faster standard channel.
- Whether other Chromium-based browser vendors mirror Chrome's exact schedule.

## Uncertainties

- Mozilla has described the move as a transition and operational details may continue to evolve as Firefox 155 moves through channels.
- Chromium-based browsers other than Chrome may use different release schedules even when they share engine changes.

## Timeline

- **2026-03-03 — Google announces Chrome's two-week cycle:** Google set September 2026 as the start of the new cadence.
- **2026-07-23 — Mozilla details Firefox transition:** Mozilla described the Firefox 155 Beta transition and two-week release train.
- **2026-09-08 — Chrome 153 stable scheduled:** Chrome 153 is scheduled as the first stable release under the new two-week cadence.

## Sources

- [Get features faster with Chrome's two-week release cycle](https://developer.chrome.com/blog/chrome-two-week-release) — Chrome for Developers · primary · 2026-03-03T00:00:00+13:00. Chrome timing, channel scope and Extended Stable exception.
- [Firefox Release Changes and Localization](https://blog.mozilla.org/l10n/2026/07/23/firefox-release-changes-and-localization/) — Mozilla · primary · 2026-07-23T00:00:00+12:00. Firefox transition point and release-train implications.