As long as the website you're visiting loads as u0022httpsu0022, it should be safe to send your passwords over WiFi in China. If you're still uneasy, you can use a VPN to further secure your connection or you can change your passwords when you return from China (you'll want to use a u003ca rel=u0022noreferrer noopeneru0022 href=u0022https://www.allthingssecured.com/password-checker/u0022 target=u0022_blanku0022u003epassword checkeru003c/au003e to make sure they're strong).