At the end of each month, Adduplex publishes the results of its monthly survey, revealing the latest data about Windows 10 market share. Back in the Windows Phone era, these reports included information about Windows Phone versions, popular smartphones, etc. Nowadays, Adduplex focuses its reports only on Windows 10.
The main highlight of the April 2021 report is the fact that Windows 10 20H2 - the most recent Windows 10 version - has just crossed the 40% market share. Now, this release has almost the same user base as Windows 10 2004.
According to Adduplex, Windows 10 20H2 (also known as October 2020 Update) holds 40.1%. This value went significantly up from the previous month's 29.9%. Windows 10 2004 (May 2020 Update) lost a little of its user base. It has 40.6%, which helps the release keep its title of the most popular Windows 10 version for one more month.
Now unsupported Windows 10 1909 took the biggest hit in April 2021. After Microsoft ceased supporting this version, it lost 7.3 points. Still, quite a big chunk of Windows 10 users keeps using Windows 10, version 1909. According to Adduplex, it has 11.1% of the market. You can expect this value to continue plummeting as Microsoft forces update those hesitating to update their system to Windows 10 20H2.
Older unsupported releases remain relatively unchanged. Windows 10 1903 has 3.3% (down from 4.6%), 1809 has 1%, 1804 has 1.4%, and other versions together accumulate 1.8%. The number of Windows Insiders went up from 0.5% to 0.7%.
To prepare the April 2021 report, Adduplex used data gathered from around 70,000 computers and over 5,000 apps with Adduplex SDK. The 70,000 figure is extremely far from 1+ billion devices running Windows 10, so there is clearly room for mistakes. Still, reports from Adduplex are the only source that sheds some light on Windows 10 market fragmentation. You can learn more about the latest data on Adduplex's official website.