How is a GTIN check digit calculated?

Working from the right, multiply digits alternately by 3 and 1, sum the results, then take whatever value brings that sum up to the next multiple of ten. That value is the check digit.

Does the barcode tell me the country of origin?

No. The GS1 prefix identifies the numbering organisation where the brand owner registered. A product with a 50x prefix was registered by a UK company; it may have been made anywhere.

What is the difference between UPC, EAN and GTIN?

GTIN is the umbrella standard. UPC-A is GTIN-12, EAN-13 is GTIN-13. A UPC is simply a GTIN-13 with a leading zero, which is why modern systems store everything padded to 14 digits.

GTIN / UPC Decoder

Validate GTIN and UPC check digits and read the structure of a product code.

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RAW INPUT

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Output appears here as you type — decoded on your device.

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What is the GTIN / UPC Decoder?

A GTIN decoder validates the check digit of a Global Trade Item Number — GTIN-8, GTIN-12 (UPC), GTIN-13 (EAN) or GTIN-14 — and breaks the number into its company prefix, item reference and check digit.

GTIN is the umbrella term for the product numbers printed under retail barcodes. GTIN-13 (EAN-13) is the global standard, GTIN-12 is the 12-digit UPC-A used in North America, GTIN-8 is the compact form for small packaging, and GTIN-14 adds a packaging-level indicator digit for cases and pallets. Shorter forms are zero-padded to 14 digits when stored, so all four are directly comparable.

Every one ends in a check digit computed the same way: multiply digits alternately by 3 and 1 from the right, sum them, and the check digit is whatever brings the total to the next multiple of ten. That single digit catches the overwhelming majority of manual keying errors.

The leading digits are a GS1 company prefix, assigned to the brand owner — which is why the prefix indicates where a company registered, not where a product was manufactured. Reading it as a country of origin is a persistent and incorrect internet claim.

GTIN / UPC Decoder at a glance

Forms: GTIN-8, GTIN-12 (UPC), GTIN-13 (EAN), GTIN-14
Check digit: Alternating ×3/×1 weights, rounded up to a multiple of 10
Prefix: GS1 company prefix — registration, not manufacture
Storage: Zero-padded to 14 digits for comparison

How to use the GTIN / UPC Decoder

1Enter the GTIN, UPC or EAN exactly as printed under the barcode.
2Read the detected form and the component breakdown.
3Confirm the check digit validates before entering the code into a catalogue.

When you would reach for it

Validating product codes during a catalogue or PIM data import.
Computing the correct check digit before generating a barcode.
Diagnosing why a scanner rejects a printed label.

GTIN / UPC Decoder — frequently asked questions

Last reviewed 25 July 2026 · questions or corrections: contact@decoder.tools