BD09 to GCJ02

Convert BD09 coordinate system (Baidu Coordinate System) to GCJ02 coordinate system

Reverse Conversion

Convert Baidu coordinates back to Mars coordinates

Good Compatibility

Better suited for Amap and other common map services after conversion

Standard Algorithm

Use stable reverse conversion formula

Coordinate Conversion

Convert coordinates from BD09 system to GCJ02 system

Longitude

Latitude

About

BD09 to GCJ02 converts Baidu Map coordinates back to the common domestic coordinate system.
Suitable for transferring Baidu Map data to other domestic map services.
Commonly used for data alignment across multiple map platforms.
The conversion logic balances precision and batch processing performance.

How to Use

1
Paste BD09 coordinates exported from Baidu Maps or the Baidu Maps API — one point per line, in latitude, longitude order.
2
Click Convert and the BD09 offset is analytically reversed, restoring the underlying GCJ02 (Mars) coordinates without iteration.
3
Copy the results for Amap, Tencent Maps, and other domestic platforms, or download the batch as a file. Free, no registration, fully local processing.

FAQ

QWhich direction does this conversion cover?

AIt moves data out of the Baidu ecosystem into the common domestic standard. Choose it when POIs, tracks, or geocoding results from Baidu need to appear correctly on Amap, Tencent Maps, or any GCJ02-based service.

QWhy convert to GCJ02 instead of straight to WGS84?

AIf your target is another Chinese map service, GCJ02 is its native system and this reversal is mathematically exact. Chaining on a further GCJ02-to-WGS84 step adds a small iterative error, so only do that when you actually need GPS-standard coordinates.

QHow precise is the BD09 to GCJ02 result?

AThe reversal formula is exact in the mathematical sense — precision loss beyond floating-point rounding comes only from rounding in your source data. Coordinates given to six decimal places are conserved to well under a centimeter.