Listing & Store Tools

UPC / EAN / GTIN Validator

Check UPC, EAN and GTIN barcodes for a valid check digit before you upload inventory — or calculate the missing check digit.

lockRuns in your browsercodeEmbed this calculator

Your input

Result

Valid check digits

2 of 3

A valid check digit means the number is well-formed — not that it is registered.

036000291452✓ UPC-A
4006381333931✓ EAN-13
036000291453✗ Check digit should be 2, not 3

Download your results

Branded KleverKlimb report with your inputs and results.

How it works

What it checks

Exactly what this tool does — everything runs in your browser and nothing is uploaded.

01barcode

Modulo-10 check digit

From the right, multiply digits alternately by 3 and 1, add them up, and the check digit is what brings the total to the next multiple of 10.

02rule

Supported formats

EAN-8 (8 digits), UPC-A (12), EAN-13 (13) and GTIN-14 (14). Spaces and dashes are ignored.

03verified

Valid ≠ registered

Marketplaces such as Amazon check GTINs against the GS1 database. Buy codes from GS1 (or your country’s GS1 office) so they are registered to your brand.

FAQ

Questions, answered

Q1Why does my UPC fail the check?
Usually a typo, a missing leading zero, or a spreadsheet that turned the code into a number and dropped zeros. Format barcode columns as text before editing.
Q2Can I use cheap UPCs from resellers?
They may pass this check but fail marketplace verification, because many marketplaces match the code to the brand owner in GS1’s database. Use GS1-issued codes.
Q3Is a 12-digit UPC the same as a 13-digit EAN?
A UPC-A becomes an EAN-13 by adding a leading 0 — the check digit stays the same.
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