[Online Tool] What Information Is Hidden in a Chinese ID Number? Enter One to Find Out

Have you ever looked closely at your own ID number?

Those 18 digits look random, but every segment carries meaning: the first 6 identify your household registration district, the next 8 encode your date of birth, the 17th digit's odd/even value determines gender, and the final digit is a checksum.

Toolshu's Chinese ID Number Parser takes an ID number and automatically extracts the issuing region, date of birth, and gender — and verifies whether the number is structurally valid.

🔗 Tool URL: https://toolshu.com/en/idcard

How Is an 18-Digit ID Number Structured?

Under the national standard GB11643-1999, the 18-digit Resident Identity Number is organized as follows:

Digits 1–6: Address code. Represents the administrative district code of the holder's registered household location, down to the county, city district, or township level. These six digits map to a specific province, city, and district.

Digits 7–14: Date of birth. Format is YYYYMMDD — the birth year, month, and day read directly from the number with no separators.

Digits 15–17: Sequence code. A sequential number assigned to people born on the same date within the same address code area. The 17th digit indicates gender: odd = male, even = female.

Digit 18: Check digit. Calculated from the preceding 17 digits using the ISO 7064 standard, used to verify that the entire number is valid. The check digit may be 0–9, or the letter X (representing the value 10).

What About the Old 15-Digit ID?

China's first-generation ID cards, introduced in 1984, used a 15-digit format — no check digit, and birth year was only two digits (e.g., 84 for 1984). The second-generation 18-digit ID card rollout began in 2004, and 15-digit cards were fully retired on January 1, 2013.

This tool supports automatic recognition of 15-digit ID numbers and can convert them to the corresponding 18-digit format.

Common Use Cases

Validate a number's legitimacy: When you receive an ID number on a contract or registration form, paste it in to verify the checksum — quickly catches any transcription errors.

Decode the issuing region: When you only have the number and not the physical card, the first six digits can be used to identify the registered province, city, and district.

Development and testing: When building systems that need ID number format validation logic, use this tool to quickly check whether your test data is structurally valid.

A Note on Privacy

This tool performs format parsing and checksum validation only. It does not make any network requests, does not upload your input to any server, and does not log anything. All computation runs locally in your browser.

That said: an ID number is sensitive personal information. Exercise appropriate caution whenever you use or transmit it in any context.

👉 Parse your ID number now: https://toolshu.com/en/idcard

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