How does the check-character validation work?

The 18-digit ID uses the ISO 7064 MOD 11-2 algorithm. The first 17 digits are multiplied by the weights 7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2, summed mod 11, and mapped to a check character (0-9 or X). The card is valid only if that matches the 18th character.

How accurate is the decoding?

The province, date of birth (YYYYMMDD) and gender (17th-digit parity) follow the documented GB 11643 structure and are accurate, and the check character is verified exactly. The tool never confirms the ID belongs to a real, registered person.

Is my ID number sent anywhere?

No. This tool is privacy-first — all processing happens locally in your browser and the number never leaves your device.

China Resident ID Decoder & Validator

China Resident Identity Card decoder

Decode and validate an 18-character Chinese Resident Identity Card number (居民身份证, GB 11643). The tool reads the province from the address code, the embedded date of birth (YYYYMMDD), and the gender (from the 17th digit — odd is male, even is female), and verifies the ISO 7064 MOD 11-2 check character (which may be a digit or X).

It is privacy-first: nothing leaves your browser. The validator checks the number’s internal consistency only and never queries any government database.