01
How GTIN validation works
The final digit is held aside and the remaining digits receive alternating weights of three and one from the right.
CalculatorsFREE · NO SIGNUP
GTIN Validator
Validate the length and GS1 modulo-10 check digit of a GTIN-8, GTIN-12, GTIN-13, or GTIN-14 without claiming registry ownership.
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01 USE IT NOW02 NO ACCOUNT03 FIELD NOTES BELOW
WORKING INPUTS
Catch a mistyped GTIN before it enters the catalog.
LIVE RESULT
GTIN checksum result
VALID GTIN-13The supplied final digit matches the GS1 modulo-10 check digit. This does not verify registry ownership.FORMATGTIN-13
EXPECTED CHECK DIGIT1
SUPPLIED CHECK DIGIT1
NORMALIZED GTIN4006381333931
12
CHECKSUM IS NOT OWNERSHIP
One digit can catch many transcription errors
The GS1 check digit validates number structure. It cannot prove that the prefix is licensed or that the code belongs to the product in front of you.
WORKING VIEW
VALID GTIN-134006381333931
METHODGS1 modulo-10 check digit
WORKING NOTEExpected and supplied check digit: 1
INPUTS → CLEAR OUTPUT
THE FIELD NOTES
Quick answer above. Better decisions below.
Use the result now, then read the practical notes for assumptions, examples, limitations, and the choices behind it.
4006381333931VALID GTIN-13
Expected and supplied check digit: 1
02
Recognize the four GTIN lengths
GTIN-8, GTIN-12, GTIN-13, and GTIN-14 use the same check-digit method.
03
Use a failed checksum as a data-quality signal
A mismatch usually points to a mistyped, incomplete, or incorrectly constructed number.
04
Verify identity separately
A valid checksum does not query Verified by GS1 and does not verify company ownership.
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How GTIN validation works
The final digit is held aside and the remaining digits receive alternating weights of three and one from the right.
The expected check digit is the amount needed to reach the next multiple of ten.
Recognize the four GTIN lengths
GTIN-8, GTIN-12, GTIN-13, and GTIN-14 use the same check-digit method.
The length describes the number format, not whether the product record is genuine.
Use a failed checksum as a data-quality signal
A mismatch usually points to a mistyped, incomplete, or incorrectly constructed number.
Correct the source record before publishing it to a marketplace catalog.
Verify identity separately
A valid checksum does not query Verified by GS1 and does not verify company ownership.
Use the official registry when identity or licensing matters.
Questions, answered.
What GTIN formats can I validate?
The checker accepts 8-, 12-, 13-, and 14-digit GTINs after optional spaces and hyphens are removed.
Does a valid checksum prove the barcode is registered?
No. It only confirms that the digits satisfy the GS1 modulo-10 rule.
Is a UPC a GTIN?
A 12-digit UPC-A number is commonly represented as GTIN-12 and uses the same GS1 check-digit rule.
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