NetApplications (mobile web usage, 201305, chart 001)

Next to email, a mobile browser is often the most-used app on a smartphone or tablet. Although Safari still rules the iPhone and iPad crowd, there is a bit of internecine warfare within the Android camp. Google’s Chrome is increasingly the default browser on Android mobile devices as usage declines for the stock Android browser.

The gains in May by Chrome against the stock Android mobile browser coincide with Google’s decision last year to replace the stock Android browser with Chrome on all Android devices…

According to the latest data by NetApplications, based on monitoring 40,000 web sites in the United States, Safari had 59.98 percent of the mobile browser market, up slightly from 59.42 percent in April.

The stock Android browser fell two percentage points during the April-May period, an eight-month low point. While the mobile version of Chrome rose less than a single point, May’s 3.22 percent is a huge leap from July 2012, when it registered just 0.34 percent of the market.

What is intriguing is that during the period after which Google began pre-installing Chrome on Android devices, the default Android browser didn’t gain any ground.

NetApplications (mobile web usage, 201305, chart 002)

This shows “Chrome’s share is all coming in new device sales, and not as a result of people switching from one to the other on their own devices,” writes Darrell Etherington at TechCrunch.

If Android lost some ground in the mobile browser race, who benefitted?

No one in particular.

Apple is mostly flat, BlackBerry, Symbian and Java ME “experienced small bumps,” according to Etherington.

Also noted was the stock Android browser usage fell at a time when two Android headliners – Samsung’s Galaxy S4 and the HTC One – premiered.