Together, We Build a Better Web

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

Latest Blog Post

Mozilla has shipped Firefox 60 Beta and Developer Edition. Check out our Firefox 60 compatibility notes to get prepared for the final version coming early May.

As you’ll see, there are several security-related changes including secure context requirements along with the first round of the Symantec certificate distrust actions. If you have a SSL/TLS server certificate with the GeoTrust, RapidSSL, Symantec, Thawte or Verisign brand, take an immediate action to avoid Insecure Connection error pages on your site. Don’t have any certificate yet? Get yours from Let’s Encrypt today, for free.

Array.prototype.values() being re-enabled with Firefox 60 was an example of how adding a new feature could break existing web apps, and it’s not new or the last — Array.prototype.find() added with Firefox 25 broke sites using the Sugar library, while Array.prototype.flatten() being implemented is known to affect MooTools which actually had the same issue with String.prototype.contains(). Be sure to keep your JavaScript library updated!

Documents

Browse by Version

Browse by Category

Browse by Status