Reverted Gecko build date in the UA string has been replaced with the version number

Published: | Categories: Networking


The notation of Gecko, the rendering engine of Firefox, in the user agent (UA) string has been changed. The build date, that has been fixed since Firefox 4, was replaced with the version number. Thus Gecko/20100101 will be Gecko/17.0. You should be careful if you’re detecting browser version from UA strings.

Update on Nov 30: This change has been backed out from Firefox 17.0.1 as it may have a major impact on site compatibility.