Effective from 15th July 2024, the National Immigration Adminisitration of the People's Republic of China has decided to futher expand the implementation of the 144-hour visa-free transit policy, see https://en.nia.gov.cn/n147413/c162409/content.html for details.
Please note:
If the validity of your passport or your travel document is less than 3 months,
if you've ever been stamped for a visa rejection on your passport,
if you've illeagally crossed the border of China, illeagally stayed your visa or permit, or illeagally worked in China, etc.
China Immigration Inspection will not approve your entry permit.
Links:
144-hour Visa-Free Transit in Beijing
https://english.beijing.gov.cn/travellinginbeijing/144hourvisafreetransit/index.html
144-hour Visa-Free Transit in Shanghai
https://gaj.sh.gov.cn/crj/ka144/default.jsp
144-hour Visa-Free Transit in Guangzhou
https://gz.gov.cn/guangzhouinternational/home/bulletin/content/post_9254377.html