Last month, it looked like Firefox's relinquishing of the second place browser spot was inevitable. In May, Mozilla's browser market share had dropped below 20 percent. It was just 0.14 points ahead of Google's Chrome.
But Firefox has somehow fought back. Chrome's share is down, Firefox's is up, and there's almost a point separating the two.
Internet Explorer dropped slightly while remaining dominantly in first, down 0.05 points to 54.00 percent. Firefox gained 0.35 points to 20.06 percent while Chrome fell 0.50 points to 19.08 percent. Safari and Opera both made small gains, of 0.11 and 0.03 points, giving them shares of 4.73 and 1.60 percent respectively.
The last couple of months have seen only slight declines for Internet Explorer. Microsoft's browser is still losing share, but at a much slower rate than we saw a year ago. This suggests the steady half a point per month erosion of its share may be at an end.
Firefox's gains and Chrome's losses are both a little surprising. Chrome suffered setbacks earlier in the year after Google penalized itself for improper advertising and promotion, but it looked like the company had resumed its trend of steady gains.
Counting browser market share remains difficult. The information source we use, Net Marketshare, strives to assess the proportion of Web users using each browser. To do this, it uses demographic data from the CIA World Factbook to provide national weightings that it applies to the raw counts it collects. Other sources, such as the widely quoted StatCounter, only denote the relative number of webpages viewed in each browser. That site explicitly eschews such weighting techniques. The main result of this is that Net Marketshare places greater importance on Internet Explorer-dominated markets such as China while StatCounter, in contrast, places much more weight on North American usage patterns. Accordingly, that metric gives Chrome a slight edge over Internet Explorer, at 32.76 percent to 32.31 percent.
Further confounding matters, Google announced at its I/O conference last week that it had 310 million Chrome users, and that there were 2.3 billion Internet users in total. Assuming that most of these Internet users use the Web at least occasionally, this gives Chrome a share of just 13.4 percent of the Internet-using public.