Map Coordinate Converter
Convert between WGS84, GCJ-02 (Mars coordinates) and BD-09, with the offset distance shown for each.
Raw GPS coordinates. Used by OpenStreetMap, GeoJSON and most non-Chinese services.
The mandated offset system for mainland China. Amap, Tencent and Google China use it.
Baidu’s own layer on top of GCJ-02. Only Baidu maps and APIs use it.
WGS84 → GCJ-02 uses the published encryption formula and matches mainstream implementations exactly; the reverse has no closed form and is solved by iteration to under 1e-9 degrees (about 0.1 mm). Baidu’s formulas carry 0.00002 and 0.000003 correction terms, so BD-09 round trips are off by about 2 cm by construction. No offset is applied outside mainland China.
About Map Coordinate Converter
Convert between WGS84, GCJ-02 (Mars coordinates) and BD-09, with the offset distance shown for each.
The work happens in your browser: what you paste is never sent to a server, and no account is needed.
More in this category
Comments
We only read your public GitHub username and avatar — no email, no write access. Comments are limited to 140 characters, cannot be edited, and can be deleted within 24 hours.
You can delete your own comment within 24 hours. Comments cannot be edited.
No comments yet — be the first.
Loading comments…