Browser crash data from Sauce Labs reveals that, although over the long term IE has been the worst performing browser, if you consider the latest browser version it has cleaned up its act considerably.

As a testing-as-a-service company, Sauce Labs is in a good position to discover which browsers cause the most errors.

It explained its methodology in a recent blog post:

By looking at metadata on the over 50 million tests run on Sauce, we can see which browsers cause the most errors.

Sometimes errors we see are caused by connectivity issues or bugs in code. But sometimes, those errors are caused by the browser itself crashing. Sauce will actually reboot the browser and rerun the test when this happens, without you even knowing (magic!), but we record all the instances of this happening. From this, we can see the error rate of all the different browsers we support.

Looking at the chart of all tests ever run on Sauce, which go back over 4 years, IE is way in the lead with an error rate of 0.25%.

(click chart to enlarge)

However if you split out browser versions, it is immediately apparent that IE 6 and IE 7 are the main culprits with 0.31% and 0.29% respectively.

And when you look at the error rate for the latest browser versions IE is no longer the most error prone - that accolade now goes to Safari 6 with an error rate of 0.12, followed by Opera 12 at 0.08%, while IE 10 has a respectable 0.04%.

What is clear from this final chart is how much more reliable the most recent browsers are. Chrome 27 has an error rate of 0.02% and Firefox, which has always been the most stable, has such a low rate that it doesn't even show on the chart.