6 out of 10 to 11 million websites that is. The Netcraft survey has a different sample, where w3tech test the 10 million largest websites of Alexa and Tranco

6 out of 10 to 11 million websites that is. The Netcraft survey has a different sample, where w3tech test the 10 million largest websites of Alexa and Tranco top 1 millions websites, it seems like Netcraft samples every host they know of to get sites and in 2013 it was about 630 million sites tested and then either look at php file extension or response header. Thus you are comparing apples to oranges. Both can still be true.