Together, We Build a Better Web

A community-driven Web developer engagement initiative focused on the backward compatibility in Firefox. Documents, tools, latest updates & more.

Latest Blog Post

Mozilla shipped Firefox 80 Beta and Developer Edition today. So far, we have posted four site compatibility notes, and one of them is something that has been postponed because of the COVID-19 pandemic.

Yes, breaking changes are gradually coming back with the upcoming releases. To repeat, these things are currently planned:

Also, as a reminder, Firefox 68 ESR reaches the end-of-life soon in September. If your organization is in the process of upgrading, check out our Firefox 78 ESR site compatibility notes.


Browse by Release

Browse by Category

Browse by Status