Bulk GTIN Checker for UPC, EAN and ISBN Codes

How to use the GTIN checker

This GTIN checker tests every UPC, EAN, ISBN or GTIN-14 in your file against the GS1 check digit rule and the identifier rules in Google Merchant Center's GTIN [gtin] help page. It works with a product feed, a Shopify or WooCommerce export, a supplier price list, or codes pasted from a spreadsheet.

1. Add your codes. Drop in a CSV or Excel file, or paste one code per line. Click Try sample data to see how it works first.
2. Check the column. The tool finds the barcode column on its own (names like gtin, barcode, upc or Variant Barcode). If it guessed wrong, pick the right column from the list. Add the SKU and title columns so you can find each product later.
3. Choose how to read 8-digit codes. An 8-digit number can be an EAN-8 or a short UPC-E. Codes starting with 0 are treated as UPC-E and expanded to the full 12-digit UPC, which is what Google asks for.
4. Read the results. The summary shows valid, invalid and fixed codes. Open each problem to see the rows, what is wrong and how to fix it.
5. Download. Get the full results file, the issue report, or a clean list with only the valid GTINs.

What the checker tests

• Check digit and length — one wrong or swapped digit fails. Spaces and dashes are removed, as Merchant Center ignores them.
• Spreadsheet accidents — lost leading zeros (fixed when the check digit proves it) and scientific notation such as 6.29104E+12.
• Prefixes Google refuses — restricted in-store numbers, coupon ranges and GS1's demo prefix 952.
• Type and duplicates — UPC-A, EAN-13, ISBN-13, EAN-8, UPC-E or GTIN-14, and the same GTIN on two rows.

What to do next in Merchant Center

1. Fix the invalid rows at the source. Correct the barcode in your store (for example the Barcode field of each Shopify variant) or in your supplier sheet, so the next feed update does not bring the error back.
2. Leave unknown GTINs empty. Google says not to guess or make up a GTIN. If a product has no GTIN, send brand and mpn instead. If it has neither (for example a handmade item), set identifier_exists to no.
3. Re-upload or re-fetch your feed. In Merchant Center, open your product data source and fetch it again, or wait for the scheduled fetch.
4. Check the diagnostics. After processing, look at the product issues list. A code can pass this check and still be flagged if it belongs to a different brand.

Common GTIN errors and how to fix them

“Invalid value [gtin]”

Merchant Center shows this when the number is malformed: wrong length, letters, or a wrong check digit. Copy the GTIN again from the barcode label or your supplier. Do not just change the last digit to the one this tool shows — that turns one wrong number into a different wrong number.

“Incorrect GTIN”

This one is different: the number is well formed, but it belongs to another product — often a code that was re-used for a new item or bought from a barcode reseller. A check digit test cannot catch this. Use the manufacturer's GTIN for this exact product (Google's help page for this error).

“Restricted GTIN”

Numbers starting with 02, 04 or 2 (on the 13-digit form) are restricted circulation numbers. Shops print them on things like weighed cheese or in-store labels. They are not real product GTINs. Google's GTIN rules say not to submit them. Use the manufacturer's GTIN, or brand plus MPN.

“Unsupported GTIN” (coupon ranges)

Codes starting with 05, 98 or 99 belong to coupon and refund-receipt ranges, so Merchant Center rejects them as product identifiers.

Two variants with the same GTIN

Each size and color is a different product and needs its own GTIN. If your supplier gave one code for a whole product line, ask for the variant codes.

Your ISBN has 10 digits

Google needs the 13-digit ISBN. You can find it on the book itself. An old 9-digit SBN must also be replaced by the 13-digit ISBN.

Cheap “barcode reseller” numbers

A number bought from a reseller can pass the check digit test and still be registered to another company. Google's unique product identifiers page explains that GTINs must match the brand. If you make your own products, get a GS1 company prefix in your country.