As Google touted Chrome's fourth launch anniversary on Tuesday, a pair of Web measurement firms continued to argue about whether the browser is still gaining ground or has stalled.
According to California-based Net Applications, Chrome's share of all browsers grew by a quarter of a percentage point to 19.1% in August, returning Chrome to a mark it set in December 2011 but still off its peak of 19.6% in May 2012.
Meanwhile, rival StatCounter pegged Chrome on a downward slope for August, saying the browser lost two-tenths of a point to slip to 33.6%.
What was most striking about the figures was that they were contrary to each firm's longer-running trends.
Net Applications, for example, has tracked declines by Chrome in five of the last eight months after monitoring a nearly-perfect run of increases from the browser's debut in September 2008.
On the other hand, StatCounter, which claimed Chrome dipped last month, has regularly showed gains for Google's app: August was the first time in almost four years that the Irish measurement firm put a negative number in Chrome's change column.
The two analytics companies' dispute over Chrome's rise -- or fall -- is the latest line in a chorus of bickering over which delivers the more accurate usage estimates, an argument that grew heated in June after StatCounter claimed Chrome had slipped past Microsoft's Internet Explorer (IE) to take the poll position in the race for the world's most-used browser.
Even though Chrome's lead over IE was cut by more than half in August compared to the month before, StatCounter said Google still topped Microsoft.
The one thing both Net Applications and StatCounter can agree on is that Chrome steadily gained usage share in its first three years. According to Net Applications, Chrome climbed from just a 1% share after its first month of availability in September 2008 to 3.2% on its 2009 anniversary, to 8.2% in 2010 and to 16.2% in 2011.
StatCounter tracked a similar rise from 1% in 2008 to 3.7% in 2009, then to 11.5% and 23.6% in 2010 and 2011, respectively.
Over the last year, however, things got muddier: StatCounter continued to track a steady rise in Chrome, but Net Applications noted first a softening, then a regular slide in the browser's usage.
By Net Applications' numbers, Chrome remains in third place, behind both IE and Mozilla's Firefox. StatCounter claims Chrome is in the No. 1 spot, with IE and Firefox following.
In browser news outside Chrome, both metrics vendors tracked a quick climb in Safari 6, the OS X browser that runs only on 2011's Lion and this year's Mountain Lion: Safari 6 accounted for 36% of all copies of Apple's desktop browser in August, up dramatically from 6% in July, said Net Applications.
StatCounter also reported an increase in Safari 6, from 2% of all copies of the browser in July, to 16% in August. Apple released Safari 6 on July 25, the same day it launched OS X Mountain Lion.
Neither Net Applications nor StatCounter has begun tracking Internet Explorer 10 (IE10), the browser Microsoft is bundling with Windows 8 and the tablet-targeting Windows RT, and which it's promised to offer to Windows 7 users.
Google celebrated the fourth anniversary of Chrome's 2008 launch -- the browser hit the Web on Sept. 2, 2008, as a beta for Windows only -- with what it called the "Chrome Time Machine," a timeline of the browser's progress.
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.