International · Indonesia
Indonesia NIK checker.
Decode a 16-digit NIK (Nomor Induk Kependudukan, the KTP number): province code, birth date and gender. Browser only; nothing is sent.
How it works: A NIK has 16 digits: 2 for province, 2 for regency or city, 2 for district, 6 for the birth date as DDMMYY (women have 40 added to the day), and 4 serial digits. There is no check digit, so this tool tests structure only.
Inputs
Test values (not real people’s numbers):
Result
Enter a number and press Check.
How the Indonesia NIK check works
A NIK has 16 digits: 2 for province, 2 for regency or city, 2 for district, 6 for the birth date as DDMMYY (women have 40 added to the day), and 4 serial digits. There is no check digit, so this tool tests structure only.
| Digits | Meaning |
|---|---|
| 1-2 | Province code |
| 3-4 | Regency or city code within the province |
| 5-6 | District (kecamatan) code |
| 7-8 | Day of birth; 40 is added for women, so 41 to 71 means a female born on day 1 to 31 |
| 9-10 | Month of birth |
| 11-12 | Last two digits of the birth year |
| 13-16 | Serial number |
Worked example, 3171011708450001: province 31 is DKI Jakarta, regency/city 71 and district 01 are codes within it, 17 / 08 / 45 is 17 August 1945 (2045 would be in the future), and the day 17 is below 40, so the day field reads male. For 3171015708450001 the day is 57, which is 17 + 40, so the same birth date reads female.
What this tool cannot tell you
Only Dukcapil (or an authorised institution with access to its data) can confirm whether a NIK is registered and whom it belongs to. This tool cannot and does not. A passing result means the number is well formed. It does not mean it was issued, is current, or belongs to anyone. Official sources to use instead: Dukcapil, Directorate General of Population and Civil Registration.
Where each rule comes from
Not every issuer publishes its check rules. This table says, for each rule used here, who documents it and how firmly.
| Rule | Source | Status |
|---|---|---|
| 16-digit layout, DDMMYY date with +40 for women | python-stdnum id/nik documentation; Indonesian Wikipedia, Nomor Induk Kependudukan | Documented by third parties, cross-checked |
| Two-digit province codes | Kemendagri region codes as reproduced in python-stdnum id/loc.dat; code 65 (Kalimantan Utara) added from the same national list. Papua-region codes 91 to 96 changed in 2022, so the tool does not name the province for them. | Documented by third parties, cross-checked |
| No check digit | None is described by Dukcapil or by the cross-checked implementations | Documented by third parties, cross-checked |
Frequently asked questions
How do I check a NIK number?
Enter the 16 digits. The tool tests that the province code is known, that the district fields are not 00, and that the embedded birth date is a real date. Passing means plausible structure, not registration.
Why does the day look 40 higher for women?
In the NIK the day of birth has 40 added for women. So 57 means the 17th for a woman, and 17 means the 17th for a man.
Does a NIK have a check digit?
No. Unlike some national IDs there is no check digit, so a mistyped digit that still makes a plausible date will not be caught.
Is it safe to enter a NIK here?
Decoding happens in your browser and nothing is sent, stored or logged. Only enter numbers you are entitled to use, and do not post real NIKs publicly.
Sources
- python-stdnum, stdnum/id/nik.py (retrieved 15 October 2026)
- python-stdnum, stdnum/id/loc.dat (region codes) (retrieved 15 October 2026)
- Wikipedia (Indonesian), Nomor Induk Kependudukan (retrieved 15 October 2026)
- Ministry of Home Affairs (Kemendagri) (retrieved 15 October 2026)
Format check only — not an official verification
This tool checks structure and, where a public algorithm exists, a check digit, entirely in your browser. It does not query any government register, and it cannot confirm that a number was issued or to whom. Nothing you type is transmitted, stored or logged.