If you've ever looked at China in satellite view, you've probably noticed the roads and labels don't line up with the photos. They're shifted by about 300–700 m depending on where you are.
This isn't a Google bug. Chinese law requires maps of mainland China to use GCJ-02, a deliberately scrambled coordinate system. Google's road and place data for China is in GCJ-02, but its satellite imagery is at true GPS (WGS-84) positions, so the two never match.
I made a Chrome extension, China Satellite Align, that moves Google Maps' roads, labels, and places back to their true positions, so everything lines up:
- Roads and labels sit on the satellite photos (map, satellite, terrain and globe view) - Your location, searched places and routes are where they really are
- Coordinates Google shows (right-click, address bar) are real GPS coordinates, and you can search with GPS coordinates directly
- Optional: Street View coverage can move with the map or stay put (uploads in China are placed inconsistently)
- A small GPS ↔ GCJ-02 coordinate converter in the popup
It's free and open, collects no data, and only runs on Google Maps pages. Hong Kong, Macau and Taiwan aren't affected, since Google doesn't shift them. Near a few borders (Shenzhen–Hong Kong, Dandong) some roads and rivers can still be slightly off.
Chrome Web Store link.
Happy to answer questions!