🆔Korean RRN Format Validator
Validate the checksum of a 13-digit Korean Resident Registration Number and extract birth date, gender, and foreigner status. All processing stays in-browser for safety. Useful for form validation, auto-fill UI prototyping, and quickly checking your own RRN digits.
How to use
- 1Enter the 13-digit Korean Resident Registration Number.
- 2Checksum validity, birth date, and gender display.
FAQ
Is it safe?+
All processing happens in-browser and never transmits to any server. Verify in the Network tab if you like.
RRN structure?+
YYMMDD-SXXXXXC. First 6 = birth date; first of last 7 (S) = gender/nationality; next 4 = region/serial; last = checksum.
Gender digit (S) meaning?+
1, 3 (male, Korean); 2, 4 (female, Korean); 5, 7 (male, foreigner); 6, 8 (female, foreigner); 9 (male, born 1900s); 0 (female, born 1900s). 9/0 are fading out.
What's a checksum?+
The last digit is computed from the first 12 by a fixed rule. Random 13-digit inputs almost never pass — useful for format validation.
Does it verify actual registration?+
This tool only validates format. Real registration status is only confirmable via Ministry of Interior / Government24 with proper authentication.
Foreigner registration numbers?+
Same 13-digit structure, validated identically. Gender digit uses 5~8.
Is it OK to expose my RRN?+
Absolutely not. This tool is for self-check or development verification only. RRN is the most sensitive personal info — exposure risks identity theft.