GS1 barcode check digit calculator

Client

GS1 barcode check digit calculator for label designers and catalog managers who need the computed check digit without Excel macros. Paste partial or full strings—see expected digit on mod-10 failure.

Using the calculator

Paste GTIN digits. On pass, rightmost digit matches mod-10. On fail, tool shows digit that would validate—confirm against GS1 assignment workflow before changing databases.

Privacy: every comparison runs locally in your tab. Toolcore performs no GS1 registry lookup, product database match, or price scan—checksum math only.
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GTIN‑8, UPC‑A (GTIN‑12), EAN‑13, and logistic GTIN‑14 all end with the same ISO/IEC GS1 modulus‑10 weight‑3 algorithm used by the barcode generator when it pads shortened bodies with a check digit. Alternate lengths map to retailer packaging standards (coupon GTIN‑12, carton GTIN‑14, compact GTIN‑8).

Result

Passes modulus‑10 GS1 rule for GTIN-13 (13 digits).

Common use cases

  • Compute check digit when assigning new item references under your prefix.
  • Verify label vendor proofs before production run.
  • Document GS1 mod-10 for internal wiki with working link.

Common mistakes to avoid

  • Calculating check digit without full intended length

    Run mod-10 on the complete GTIN string for target symbology length.

FAQ

GS1 mod-10 vs Luhn?

GS1 uses alternating 3/1 weights on retail GTINs—different from Luhn on IMEI and cards.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • gtin checksum verifier online
  • ean 13 check digit validate browser
  • upc-a modulus 10 checker locally
  • gtin 14 logistic barcode checksum
  • gs1 digit string validator no lookup

More tools

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