How to Validate GTIN, EAN and UPC Barcodes in Bulk

Invalid GTINs cause disapprovals in Google Merchant Center and listing errors on marketplaces. Most invalid numbers are not fake; they are damaged — a digit lost in a copy-paste, a leading zero dropped by a spreadsheet, a UPC padded wrongly. The free SeoSpidie GTIN validator checks a list of barcodes at once and shows which ones fail.

New to barcodes? Read what a GTIN is and how the check digit works first.

Step 1: Export your barcodes as text

Export the GTIN, EAN or barcode column from your shop, ERP or feed. Before you copy it, make sure the spreadsheet column is formatted as text. Number formatting is the single biggest cause of broken barcodes: it removes leading zeros and turns long numbers into values like 8.90123E+12.

Step 2: Paste the list

Paste the numbers into the validator, one per line. It accepts GTIN-8, UPC-A (12 digits), EAN-13 and GTIN-14.

Step 3: Read the results

Each number is marked valid or invalid. Common reasons for failure:

• Wrong check digit — usually a mistyped digit somewhere in the number.
• Wrong length — 11 or 12 digits where 13 were expected, often from a lost leading zero.
• Non-digit characters — spaces, hyphens or letters copied from a label.
• Scientific notation — the spreadsheet stored the number as a rounded value.

Step 4: Fix the failures

1. Re-copy from the source. Take the number from the product packaging, the manufacturer's data or GS1 records, not from an old spreadsheet.
2. Restore leading zeros. A 12-digit UPC can be written as a 13-digit number with a leading zero; both are valid if the digits match.
3. Strip spaces and symbols.
4. If no real GTIN exists, remove the value and set identifier_exists to no in your feed instead of keeping a made-up number.

Step 5: Check for duplicates

While you have the list open, sort it and look for repeated numbers. Two different products with the same GTIN usually means variants were given one barcode, or a number was copied by mistake. Merchant Center and marketplaces treat these as errors or merge the listings.

Step 6: Update and validate the feed

Put the corrected barcodes back in your catalogue, regenerate your feed and run it through the Merchant Center feed validator. If you also add the GTIN to Product structured data on your pages, generate it with the schema generator so page and feed match.

What validation can and cannot prove

A passing check digit proves the number is correctly formed. It does not prove the number is registered to your product or brand. Only use GTINs that come from the manufacturer or from your own GS1 membership.

Related guides

• Pinterest Shopping Catalog Setup Guide for Small Online Stores
• How to Generate a Pinterest Product Feed From Your Website
• Google Merchant Center Product Feed Requirements Explained

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