Examining the page source, there's this line: var browserVersions = [{'Firefox': '27', 'Chrome': '44', 'Chrome OS': '34', 'Opera': '30', 'Edge': '12', 'Safari'

Examining the page source, there's this line: var browserVersions = [{'Firefox': '27', 'Chrome': '44', 'Chrome OS': '34', 'Opera': '30', 'Edge': '12', 'Safari': '8', 'IE': '11'}]; Firefox 27 was released on February 4, 2014, and Chrome 44 on July 21, 2015. Since the snapshot was in October 2018, the page apparently hadn't been updated for at least 3 years. Edit: Here is a report of the bug in the wild: https://webcompat.com/issues/17258 https://webcompat.com/issues/17258