Google's Android operating system ran on 19.6 percent of the 55.7 million smartphones through August, putting the platform's market share within 5 percentage points of rival Apple iOS, comScore said.
No. 2 smartphone provider Apple also gained for the month, inching up to 24.2 percent in August from 23.8 percent in July. Android and iOS' smartphone share gains appear to be coming at the expense of Research in Motion and Microsoft.
RIM led the U.S. smartphone OS market with 37.6 percent of handsets, down 2.3 percent from its July count of 39.3 percent. Microsoft's share was 10.8 percent, down one full percentage point from July when it held 11.8 percent.
RIM and Microsoft have been slipping for some time thanks to iOS since 2007 and Android in 2010, according to most analysts.
Susquehanna Research analyst Jeffrey Fidacaro said in an Oct. 7 note: "The three-month average mobile data usage for August from comScore continues to highlight increased web browsing and application downloads as the fastest growing trends, with text messaging and accessing social media/blogs gaining..."
"We believe these usage trend benefits Apple and Android-based products at the expense of RIM and Microsoft, which is reflected in RIM's 4 percentage point U.S. subscriber share loss from May to August.:
What stands out from the data is the way Android has tempered iOS's meteoric rise. IOS commanded 25 percent of the market in April, which means the Android army of some 60-plus devices launched all over the worlds has blighted the iPhone a bit.
Indeed, thanks to devices such as Sprint's HTC Evo 4G (spring) and Verizon Wireless' popular Droid lineup, including the HTC Droid Incredible (spring), Motorola Droid X and Droid 2 (summer), Android has grown market share from 12 percent in April to nearly 20 percent.
That puts it within 5 percent of iPhone, certainly within striking distance of the popular device.
The iPhone line was got a boost in late June with the launch of iPhone 4, which sold at least a few million. However, it's launch may have been tempered by the April launch of Apple's iPad.
Analysts believe Apple sold between 8 million and 10 million of the popular tablet computers, giving it a tremendous headstart on the market.