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Mozilla announced on September 17, 2019 that it will speed up the Firefox release cycle from 2020 onward for all Firefox channels.

New Firefox versions get released every six to eight weeks currently after Mozilla switched to a variable release schedule in 2016. The browser maker started to ship new versions of the browser every six weeks in 2011 when it switched to a rapid release cycle.

Mozilla uses a phased released system that moves new code from cutting edge Nightly versions of the browser through Beta and Developer editions before they reach the stable version and the majority of users. So-called Firefox ESR (Extended Support Release) versions are maintained for Enterprises and organizations that follow the same release cycle but with less frequent feature changes.

Starting in the first quarter of 2020, Mozilla will release a new version of the Firefox web browser every four weeks.

The organization wants to introduce new features including new Web APIs into Firefox more quickly.

Quote:We’re adjusting our cadence to increase our agility, and bring you new features more quickly. In recent quarters, we’ve had many requests to take features to market sooner. Feature teams are increasingly working in sprints that align better with shorter release cycles. Considering these factors, it is time we changed our release cadence.

Mozilla won't change the release cadence of Extended Support Releases. New ESR releases will be released every 12 months with a three month support overlap between soon-to-be-retired versions and the new ESR version. New ESR releases will be released every four weeks however instead of every six to eight weeks; the decision increases the number of ESR releases of a particular version of the browser, e.g. Firefox 68.x, however.
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