GTIN Validator

How the GTIN check digit is calculated

Every GTIN ends in a mod-10 check digit that catches every single-digit typo and most transpositions. The validator runs exactly these steps for you — here is the math worked out by hand so you can verify a code anywhere.

1. Take the GTIN without its check digit 0 3 6 0 0 0 2 9 1 4 5
2. Multiply digits alternately by 3 and 1 (from the right) 0×3 3×1 6×3 0×1 0×3 0×1 2×3 9×1 1×3 4×1 5×3
3. Sum the products 0 + 3 + 18 + 0 + 0 + 0 + 6 + 9 + 3 + 4 + 15 = 58
4. Round up to the next multiple of 10 60
5. Subtract the sum — that's the check digit 60 − 58 = 2

The same algorithm applies to GTIN-8, GTIN-12, GTIN-13 and GTIN-14 — only the number of digits changes.

About this GTIN validator

This GTIN validator confirms whether a product identifier is structurally correct using the GS1 mod-10 check digit algorithm. It accepts all four GTIN lengths — GTIN-8, GTIN-12 (UPC-A), GTIN-13 (EAN-13) and GTIN-14 (ITF-14) — so you can paste any retail or logistics code without thinking about the format up front.

The check runs entirely in your browser. There's no upload step, no signup and no paid API behind it.

When to Use It

• Bulk-checking GTINs before sending a product feed to Amazon, eBay or Shopify.
• Catching mistyped digits in a supplier's spreadsheet before importing it.
• Verifying a GTIN-14 carton code matches the inner GTIN-13 item code (after wrapping).
• Confirming a freshly minted GTIN before issuing it to a printer.
• Debugging why a marketplace listing is being suppressed for an invalid identifier.

How It Works

1. Paste the GTIN Type or paste any GTIN-8/12/13/14. Spaces, dashes, underscores and dots are cleaned automatically.
2. Auto-detect the type Length determines whether the code is treated as GTIN-8, GTIN-12, GTIN-13 or GTIN-14.
3. Check the check digit We run the GS1 mod-10 algorithm and compare against the digit you provided.
4. See the result Valid codes show the detected type and cleaned number. Invalid codes show the expected check digit.
5. Copy or fix Copy the cleaned, validated code to the clipboard or apply the suggested fix.

What to Avoid

• Validating GTINs that still have spreadsheet apostrophes or thousand-separators attached.
• Assuming a structurally valid GTIN means the product exists — it only means the number is well-formed.
• Treating GTIN-14 cartons and inner GTIN-13 items as interchangeable in feeds.
• Using internal SKU numbers as GTINs — they almost never validate.
• Trusting any code where someone has 'fixed' the check digit by hand without recomputing it.

Tips & Tricks

• If validation fails with a one-off check digit, you almost certainly have a typo in the body.
• Use the Check Digit Calculator when you have the first 7/11/12/13 digits and need the missing one.
• For bulk lists, paste each GTIN in turn — batch tooling is on the roadmap.
• A GTIN-13 starting with 0 is the same code as a GTIN-12 (UPC-A) — both are valid.
• GTIN-14 'indicator digits' 1–8 mean inner packs/cases; 9 means variable measure.

GTIN Checker: Is This GTIN Valid?

A GTIN is valid when it has 8, 12, 13 or 14 digits and ends in the correct mod-10 check digit.

GS1 GTIN Check vs This Validator

Verified by GS1 shows whether a GTIN is registered to a brand owner. This validator is a GTIN check of the number only, so run it first.

GTIN-13 and GTIN-14 Validation

Both use the same calculation; the validator tells them apart by length. See the GTIN guide for where each is used.

Validating a GTIN-14 Case Code

A GTIN-14 is often an indicator digit, the item GTIN-13 without its check digit, and a new check digit. Example 10614141000415 wraps item 0614141000418.

Frequently Asked Questions