AM A GTIN (Global Trade Item Number) is the number under a product barcode. Google Merchant Center, Amazon and most retailers use it to match your listing to a known product, so a wrong digit can get products disapproved or attached to the wrong catalog page. This tool checks the number, fixes the check digit, converts between formats, checks lists of up to 1,000 codes at once and tries to find the product each number belongs to.
How to use the GTIN lookup
- Type or paste the number. Spaces, dots and dashes are ignored. The check runs as you type.
- The tool detects the format from the length: EAN-8, UPC-A, EAN-13, GTIN-14, ISBN-13 or ISBN-10.
- Read the validation result. If the check digit is wrong, the tool shows the correct one and a button to use the corrected number.
- Copy any of the conversions: UPC-A, EAN-13, GTIN-14 and, for books, ISBN-10 and ISBN-13.
- Press Validate and look up to search public product databases for a title, brand and image.
- Use the Verified by GS1 link to confirm who licensed the number.
To calculate a check digit for a new number, enter it without the last digit: 7 digits for an EAN-8, 11 for a UPC-A, 12 for an EAN-13 or 13 for a GTIN-14.
Checking a whole product list
Switch to the bulk tab and paste one number per line, up to 1,000 lines, straight from a Shopify export or a supplier sheet. You get a table with the format, result, corrected number, GTIN-14 and GS1 prefix for each row, plus counts of valid and invalid numbers, and you can download it all as a CSV. Bulk validation runs in your browser and has no daily limit.
What is a GTIN, and is it the same as a UPC?
GTIN is the umbrella name. UPC-A, EAN-13, EAN-8 and GTIN-14 are all GTINs of different lengths, managed by the standards body GS1. A UPC is the 12-digit form used mainly in the US and Canada, and an EAN is the 13-digit form used in most other countries. Add a leading zero to a UPC-A and you get the same product number as an EAN-13.
| Format | Digits | Where you see it |
|---|---|---|
| UPC-A | 12 | Retail products in the US and Canada |
| UPC-E | 8 (compressed) | Small US packages; expands to a UPC-A |
| EAN-13 | 13 | Retail products in most other countries |
| EAN-8 | 8 | Small packages with little room for a barcode |
| GTIN-14 | 14 | Cases and cartons, not single units |
| ISBN-13 | 13 | Books, starting with 978 or 979 |
A GTIN is not a SKU. Your SKU is an internal code you make up for your own stock. A GTIN is licensed from GS1 and identifies the product for everyone in the supply chain.
How the check digit is calculated
The last digit of every GTIN is a check digit calculated from the others, so a typo is almost always caught. The method is the same for all formats:
- Start from the rightmost digit before the check digit and move left.
- Multiply digits in alternating positions by 3 and 1, starting with 3.
- Add the results.
- The check digit is the number that brings the total up to the next multiple of 10 (0 if it is already one).
Example: for the UPC-A 03600029145_, the weighted total is 58, so the check digit is 2 and the full number is 036000291452. If someone types 036000291453, the tool flags it and shows that the check digit should be 2. A wrong check digit often means a different digit was mistyped, so confirm against the physical barcode before you accept the fix.
Converting between formats
- UPC-A to EAN-13: add a leading zero.
036000291452becomes0036000291452. - UPC-A or EAN-13 to GTIN-14: pad with zeros to 14 digits.
00036000291452. The check digit does not change, because leading zeros add nothing to the total. - ISBN-10 to ISBN-13: add 978 in front and recalculate the check digit.
0306406152becomes9780306406157. The tool does this for you. - Case codes: a GTIN-14 such as
10036000291459has indicator digit 1, which marks a case of the unit product, and a new check digit.
What the GS1 prefix tells you
The first digits show which GS1 member organization licensed the number. They do not show where the product was made. A company in China can license codes from GS1 US, and a German brand can manufacture in Vietnam.
| Prefix | Meaning |
|---|---|
| 000 to 019, 060 to 139 | GS1 US |
| 300 to 379 | GS1 France |
| 400 to 440 | GS1 Germany |
| 450 to 459, 490 to 499 | GS1 Japan |
| 500 to 509 | GS1 UK |
| 690 to 699 | GS1 China |
| 890 | GS1 India |
| 978 to 979 | Books (ISBN) |
| 020 to 029, 040 to 049, 200 to 299 | Restricted circulation, for in-store use only |
Numbers in the restricted ranges are for internal use, such as weighed items or store labels, and are not valid on marketplaces. The tool also flags coupon ranges, prefix 952 (reserved for examples) and prefixes GS1 has never assigned. The full list is on gs1.org.
Product lookup and Verified by GS1
The tool searches public product databases, UPCitemdb and Open Food Facts, for a title, brand and image. These databases are built from retailer and user submissions, so many valid numbers return nothing and some return outdated data. For an authoritative answer, use the Verified by GS1 link. It shows the company that licensed the number and, when the brand has submitted it, core product data. Product lookups are limited to 20 a day per visitor. Validation and conversion are unlimited.
How to get a GTIN for your product
If you make or brand your own products, license numbers from GS1 in your country. In the US, GS1 US prices in 2026 are $30 for a single GTIN with no renewal fee, or a company prefix with an initial fee and yearly renewal: $250 plus $50 a year for 10 numbers, $750 plus $150 for 100, and $2,500 plus $500 for 1,000 (source: GS1 US, checked September 2026). A single GTIN suits a seller with one or two products. A prefix is cheaper per number once you have more than about eight products or variants. Once you have numbers, print them with the barcode generator.
GTINs for Google Merchant Center and Amazon
Google Merchant Center asks for the gtin attribute on products that have a manufacturer-assigned GTIN. An invalid check digit, a restricted prefix or a number that belongs to another brand will trigger item issues and can limit how your products show. If you sell handmade or custom goods with no manufacturer GTIN, do not invent one. The guide to missing GTIN errors in Merchant Center covers what to submit instead.
Amazon requires a product ID for most categories and checks GTINs against GS1 data, so numbers bought from resellers that are not licensed to your brand can be rejected. Brands without barcodes can apply for a GTIN exemption in Seller Central.
Who uses this tool
- Shopify and WooCommerce merchants cleaning the barcode field before sending a feed to Google.
- Resellers and dropshippers checking supplier barcodes, which are often missing a check digit or pasted as scientific notation.
- Amazon sellers confirming a number is licensed to the right brand before listing.
- Bookshops converting old ISBN-10 numbers to the ISBN-13 that feeds require.
Common mistakes
- One GTIN for all variants. Each size and color is a different trade item and needs its own GTIN. In Shopify, the barcode field sits on each variant, not on the product.
- Using the supplier's GTIN for a changed product. If you bundle items, change the packaging or sell under your own brand, the manufacturer's number no longer describes what you sell.
- Buying cheap codes. Numbers resold outside GS1 may pass a check digit test, but they are registered to the original licensee, not to you, so marketplaces can reject them.
- Entering the case code for a single unit. A GTIN-14 with an indicator digit other than 0 identifies a carton. Submit the unit GTIN for products sold individually.
- Mixing up ISBN-10 and ISBN-13. Feeds use the 13-digit form starting with 978 or 979.
Warning: Spreadsheets drop leading zeros and turn long numbers into scientific notation. Format GTIN columns as text before you save a product CSV or feed file.
Troubleshooting
- "A 10-digit number is not a GTIN". A 10-digit number is usually an ISBN-10 or a UPC with the leading and check digits cut off. Copy it again from the barcode.
- An 8-digit number reads as both EAN-8 and UPC-E. Check which symbol is printed on the pack. The tool shows the UPC-A that a UPC-E expands to.
- Valid number, no product found. Normal for new, niche and private label products. Use Verified by GS1.
- The lookup found a different product. Public databases contain errors, or the number was reused. Trust GS1 over a database match.
Related tasks
If Merchant Center flags GTIN or brand problems across many products, the AM Jarvis GMC Scanner and Fixer scans a connected store for missing GTINs, missing brands and other product data issues and pushes fixes in batches. See the Google Shopping feed guide for the other attributes that matter.