Overview

Firefox offers an Extended Support Release (ESR) for organizations, including schools, universities, businesses and others who need extended support for mass deployments. Firefox ESR can be downloaded here. The ESR release is based on the regular release cycle of Firefox for desktop.

Release cycle details

ESR releases are maintained for more than a year, with point releases that coincide with regular Firefox releases. These point releases contain security upgrades.

The ESR version will also have a three cycle (at least 12 weeks) overlap between the time of a new release and the end-of-life of the previous release to permit testing and certification before you deploy the new version to your organization.

We rely on Firefox ESR users to provide feedback for each new ESR release. During the first two cycles, please report any bugs such as web compatibility regressions and stability issues.

Maintenance of each ESR through point releases is limited to high-risk/high-impact security vulnerabilities, and in rare cases may also include off-schedule releases that address live security vulnerabilities. Backports of any functional enhancements and/or stability fixes are not in scope.

At the end of the support period for an ESR version:

• the release will reach its end-of-life
• no further updates will be offered for that version
• an update to the next version will be offered through the application update service

You can read more about the ESR landing process here.

Upgrade path between two ESR versions

An ESR release will be automatically upgraded to the subsequent ESR release. System administrators can disable automatic updates by managing ESR through their deployment system. From one major version to another, such as the version 115 to version 128 migration, the updates will be implemented only after version X.3.0 is released. For example, users of version 115 will be updated only when version 128.3.0 has been published.