How does the check-digit validation work?

The Thai National ID uses a mod-11 check digit. The tool multiplies the first 12 digits by weights 13 down to 2, sums them, then computes (11 - (sum mod 11)) mod 10. The card is valid only if that result equals the 13th digit.

How accurate is the validator?

The check-digit test is exact and uses the official algorithm, so it catches typos and many invalid numbers. A number that passes is structurally consistent but the tool never confirms it belongs to a real, registered person.

Is my National ID sent anywhere?

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

Thailand National ID Validator

Thailand National ID validator

Validate a 13-digit Thai National ID (เลขประจำตัวประชาชน). The tool recomputes the official mod-11 check digit — weights 13 down to 2 over the first twelve digits, then (11 - (sum mod 11)) mod 10 — and tells you whether it matches the 13th digit. It also reads the person-type digit, province code and district (amphoe) code.

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