Canadian · Validation
GLN / SSCC / GTIN check digit validator.
Validate the check digit of a GS1 identification key: GTIN-8, GTIN-12, GTIN-13, GTIN-14, a 13-digit GLN (Global Location Number), a 17-digit GSIN or an 18-digit SSCC (shipping container code). Or enter the number without its check digit to have it computed. Everything runs in your browser: nothing you type is transmitted anywhere.
Inputs
Result
Enter a number and press Check.
How the GS1 check digit works
GS1 states that one check digit algorithm is “identical for all fixed length numeric GS1 data structures” that carry a check digit, including GTIN-8, GTIN-12, GTIN-13, GTIN-14, the 13-digit GLN, the 17-digit GSIN and the 18-digit SSCC. Starting with the digit next to the check digit and moving left, multiply the digits alternately by 3 and 1, add the results, and subtract the sum from the nearest equal or higher multiple of ten. That difference is the check digit.
GS1's own worked example uses the 17-digit body 37610425002123456. The weighted sum is 101, the next multiple of ten is 110, so the check digit is 9 and the full 18-digit number is 376104250021234569. Paste it above to see it pass.
What this does and does not tell you
A matching check digit means the number is well-formed and unlikely to contain a single typo or a swapped pair of most adjacent digits. It does not prove the GLN, SSCC or GTIN was ever issued by GS1 or belongs to a real location, pallet or product. For plain 12 and 13-digit product barcodes there is also the EAN-13 / UPC-A validator.
Source: GS1 General Specifications, Release 26.0 (ratified January 2026), section 7.9.1, Tables 7-8 and 7-9, gs1.org.