China has three state-owned mobile operators: China Mobile, China Unicom, and China Telecom. All three have launched 5G on a massive scale. China has more 5G base stations than the rest of the world combined. Coverage is exceptional in cities and extends deeply into rural areas.
Beijing, Shanghai, Guangzhou, Shenzhen, Chengdu, Xi'an, and all major cities have strong 5G coverage. 4G LTE extends across virtually all inhabited areas of the country, including rural villages and major highways. The Three Gorges area, the Tibetan Plateau in Lhasa, and the remote western regions of Xinjiang have 4G coverage in main towns, though some high mountain trails in Tibet and remote desert areas have weaker signal.
HelloRoam China eSIM plans connect to China Mobile or China Unicom networks, giving travelers access to China's world-class network infrastructure. However, all data traffic on Chinese networks is subject to Great Firewall filtering. Foreign travelers lose access to Google Maps (use Baidu Maps or Apple Maps which work partially), WhatsApp, Gmail, and most social media. Download offline maps, WeChat (China's primary messaging platform), and any other China-specific apps before you arrive or via a VPN-equipped device before crossing the border. Note that Baidu Maps, WeChat, and local apps all function without restriction on Chinese networks.