We analyzed millions of browser sessions using Sauce Labs to determine the reliability of various browsers. We found that Safari 5 is significantly less reliable than other browsers, even when running on our newer infrastructure and in proxy mode. However, when we corrected for proxy mode, Firefox performed better than expected, and Chrome was unaffected by it. The study reveals that while modern browsers are generally more reliable, some older versions can still be problematic. Interestingly, the Safari 5 results were initially surprising but turned out to be a result of our specific testing environment rather than any inherent flaw in the browser itself.