China Visa Check answers one question for every passport: do you need a visa for mainland China? Pick your passport and the first line tells you, with the date it was checked and links to the official Chinese sources. It covers the 30-day visa-free list and when it ends, 240-hour visa-free transit, Hainan entry and mutual exemptions. Free, in 10 languages, no sign-up. The rules are open data (CC BY 4.0), and there is a free checker you can embed on your own site.