Usablenet is leading in Top 100K Sites and Top 1M Sites.
Usablenet has better usage coverage in more websites categories. Including Business & Industry, Shopping, Accommodation & Hotels, Travel and 31 other categories.
Vertster is leading in Computer & Electronics, People & Society, Computer Hardware, Career & Education and 6 other categories.
Usablenet is leading in most countries, including United States, United Kingdom, Italy, Canada and 10 other countries.
Vertster is leading in Australia and Brazil.