Firefox versus IE: Browser Market Shares over Time

NOVEMBER 11, 2008

It would be interesting to chart over time the progress of open-source, standards compliant, Mozilla-type web browsers (e.g. Firefox) versus Microsoft’s Internet Explorer. As is often the case in other areas, it is not easy to get good (open) data over a reasonable time period. The graph below shows browser market share as measured by the browser usage of visitors to the W3Schools website (data source on Open Economics plus the code to extract original data into this usable form).


Browser Market Share (NB: Firefox was released in Nov 2004 but not listed separately by W3Schools until 2005)

Given the source, and therefore the bias towards more technically savvy users, these figures probably overstate Firefox’s market share somewhat, though the overall trend is probably largely correct. What we see is a steady and continuing increase in Mozilla (Firefox) market share ever since Firefox’s launch in Autumn 2004 and a concomitant decline in market share of IE (the little dip for Firefox at the end appears to be directly attributable to the launch of Google’s chrome). What is particularly interesting is that, at least for W3Schools users, we are almost at the point where there are as many people using Firefox as IE. This is significant for several reasons.

First, because of its level of usage it will no longer be possible for websites to only ‘work in IE’ but instead will always have to work in Firefox as well. This is both good for Firefox and for the standards-compliant browsers more generally (while, of course, Firefox itself is not perfectly standards compliant it has traditionally been much better than IE).

Second, it is an (unusual) example of a case where dominance has not been maintained. Generally a firm with established dominance in a given area is able to maintain – witness the robustness of Microsoft’s established dominance in other areas. By contrast, in this market, as the graph shows, Firefox has almost drawn level with IE and may soon surpass it if the trend of the last few years continues.