LatLong Converter

GCJ-02 to BD-09 Converter

GCJ-02
BD-09
GCJ-02
BD-09

About GCJ-02 Coordinate System

1Definition

GCJ-02 (Mars Coordinate System) is a geodetic datum used in China for geospatial data. It applies an encrypted offset to WGS84 coordinates to comply with national regulations.

2Development History

Developed by the Chinese National Bureau of Surveying and Mapping, GCJ-02 was introduced to implement the national security policy on geospatial information. Most Chinese map services use this system.

3Applications

GCJ-02 is used by all Chinese government-approved map services including AMap (Gaode), Tencent Maps, and Apple Maps in China. It is required for any mapping application operating within mainland China.

Encrypted Offset

GCJ-02 applies a non-linear offset algorithm to WGS84 coordinates, shifting positions by up to several hundred meters. The exact algorithm is classified by the Chinese government.

China Region Only

The encryption offset only applies within mainland China. Coordinates outside China pass through without modification.

Industry Standard

GCJ-02 is the mandatory coordinate system for all commercial map services operating in China. Converting between WGS84 and GCJ-02 is essential for international data integration.

About BD-09 Coordinate System

1Definition

BD-09 (Baidu Coordinate System) is a geodetic system developed by Baidu, based on GCJ-02 with additional encryption for use in Baidu Maps and related services.

2Development History

Baidu developed BD-09 by applying a secondary encryption layer on top of GCJ-02 to further obfuscate coordinates. It is proprietary to Baidu and used exclusively in their mapping ecosystem.

3Applications

BD-09 is used exclusively in Baidu Maps, Baidu Navigation, and Baidu LBS API. It is the most encrypted coordinate system among Chinese map services.

Double Encryption

BD-09 adds a second encryption layer on top of GCJ-02, making it the most heavily obfuscated coordinate system used in China.

Baidu Ecosystem

Used exclusively within Baidu's mapping platform. If you're developing with Baidu Maps API, all coordinates must be in BD-09 format.

Third-party Conversion

Conversion between BD-09 and other systems relies on reverse-engineered algorithms that provide sub-meter accuracy.

GCJ-02 to BD-09 Conversion Guide

📐 Conversion Formula
// GCJ-02 → BD-09
x = gcjLon
y = gcjLat
z = √(x² + y²) + 0.00002 × sin(y × 3000 × π / 180)
θ = atan2(y, x) + 0.000003 × cos(x × 3000 × π / 180)

bdLat = z × sin(θ) + 0.006
bdLon = z × cos(θ) + 0.0065

GCJ-02 to BD-09 applies Baidu's proprietary secondary encryption. The transformation converts Cartesian coordinates to polar form, applies sinusoidal perturbations to the radius and angle, then converts back to Cartesian with an additive offset of 0.006° in latitude and 0.0065° in longitude.

📋 Operation Steps
  1. Input GCJ-02 coordinates from any Chinese map service (AMap, Tencent Maps, etc.)
  2. The tool applies the BD-09 encryption algorithm
  3. Output is compatible with Baidu Maps API
  4. Use the reverse conversion for integrating Baidu data with other systems
💡 Tips
  • BD-09 has the strongest encryption among Chinese coordinate systems
  • The offset between GCJ-02 and BD-09 is typically 50-100 meters
  • Baidu Maps is the only major service using BD-09

Frequently Asked Questions

The accuracy depends on the specific coordinate systems being converted. For standard geographic transformations between GCJ-02 and BD-09, typical accuracy is within sub-meter range under normal conditions. For systems requiring 7-parameter transformations, accuracy depends heavily on the quality and regional relevance of the parameters used. Always verify results for critical applications.

Yes! Our tool supports batch conversion. Simply enter multiple coordinate pairs, one per line, in the input field on this page. All coordinates will be processed simultaneously, and you can download the results as an XLSX file for further analysis or integration.

Enter coordinates in the format: latitude, longitude (one pair per line). Latitude should be the first value, longitude the second. For example: 23.05105,113.37149. Ensure latitude is between -90 and 90, and longitude is between -180 and 180.

For this conversion, standard parameters may be sufficient for most applications.

Absolutely. All coordinate conversions are performed entirely in your browser using client-side JavaScript. Your data is never sent to any server, ensuring complete privacy and security of your geographic information. This is especially important for sensitive location data.

GCJ-02 gcj-02 (mars coordinate system) is a geodetic datum used in china for geospatial data. it applies an... BD-09 bd-09 (baidu coordinate system) is a geodetic system developed by baidu, based on gcj-02 with additi. The conversion between them accounts for differences in their ellipsoid parameters, datum origins, and any encryption offsets.