Firefox 3.6 about 30% more stable than Firefox 3.5

So if you haven’t updated yet, there goes another reason to do so now.

According to a report released by Ken Kovash from the Mozilla Metrics team, Firefox 3.6 has not only seen a 40% stability improvement since its initial release (from about 6.5 crashes for every 100 users, to around 2.5), but it has already surpassed 3.5 with all its updates since its initial release about 10 months ago.

Firefox crashiness by version over time

Also worth noting is that Firefox 3.5 was significantly less stable than Firefox 3.0. Mike Beltzner, Firefox product lead,  explains in a blog comment:

[A] funny thing happened between Firefox 3 and Firefox3.5. We climbed over 20% market share, and all of a sudden a bunch of 3rd party software started building on top of Firefox. They were calling deep within our APIs, and when we changed the code in Firefox 3.5, that resulted in crashes. We had taken our eyes of the statistics, and didn’t see this happening early enough.

Much of the “crashkill” effort was discovering where this was happening, and figuring out how to work with the 3rd party vendors to rectify, as well as to bullet-proof our own code better.

And things should get even better with an upcoming update for Firefox 3.6 (Lorentz) to feature out of process plugins, which will spare us most plugin related crashes.