Mozilla's Firefox browser has lost more than 11% of its user share in the last two months, giving Google's Chrome another shot at replacing it as the world's No. 2 browser, according to new data.
Statistics from Web measurement company Net Applications illustrated a rapid decline in Firefox and a corresponding upswing in Chrome during June and July.
At the end of July, Firefox owned a 18.3% share of all desktop browsers, down 2.3 percentage points in just two months, a decline of about 11%. Meanwhile, Chrome's user share stood at 17.8%, up 2 points since May and its highest mark since October 2012.
The half-a-percentage point gap between Firefox and Chrome was the smallest since May 2012, when it appeared certain that the latter would overtake Firefox to become the No. 2 browser behind Microsoft's Internet Explorer.
In fact, Net Applications for a few hours in early June 2012 reported Chrome ahead of Firefox, but retracted the claim after revised numbers showed Chrome trailed Firefox by just one-tenth of a percentage point.
That was Chrome's moment in the spotlight: Starting in June 2012, Google's browser began shedding share, falling to a low of 15.7% in May 2013. Firefox fared slightly better, but has also lost share in the last 12 months.
Most of the losses posted by Firefox and Chrome have gone to a resurgent Internet Explorer (IE). In the past year, IE has climbed 2.7 points to a 56.6% share, an impressive 4.7 points above it's all-time low in December 2011.
Analysts have credited IE's comeback to IE9 and IE10, the popular 2011 and 2012 editions, and the widespread adoption of Windows 7, which can run both those browsers.
If Firefox and Chrome continue the trends they've set in the last 90 days, Chrome will bypass Firefox this month; the longer-range 12-month trend would delay that until April 2014.
When mobile browsers are combined with those on the desktop, Google has already stolen second place from Mozilla.
According to Net Applications, about 12.4% of all users reached the Internet in July from a mobile browser, the highest percentage since February. Google's browsers -- Chrome on desktops and mobile devices, and the stock Android browser on smartphones -- accounted for a combined share of 18.7%. Mozilla, which has no measurable share on mobile -- though it offers Firefox on Android -- owned 16.1% of the overall browser market.
Another Web measurement firm, Ireland's StatCounter, long ago called Chrome the winner over not only Firefox, but also IE. For July, StatCounter pegged Chrome with a 43.1% share, with IE and Firefox far behind at 24.5% and 20.1%, respectively.
Unlike Net Applications, which calculates browser user share by tracking unique visitors, StatCounter measures page views. The two methodologies have generated increasingly-divergent figures for IE and Chrome. StatCounter's data, however, may indicate that Chrome users browse the Web more often or for longer periods than those who rely on IE or Firefox.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is email@example.com.