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Free. No account needed.GTIN check digit
Calculate or verify a GTIN-8, GTIN-12, GTIN-13 or GTIN-14 check digit.
Result
Enter your values. Your result will appear here.
How it works
- Inspect the example or enter your own input.
- Check the units and operation, then run the tool.
- Review the result, then copy or download it. Keep a copy of your original data.
Example & practical use
Starting example: Digits: 400638133393
Limits and help
Checks arithmetic only; it does not register a barcode or verify product ownership. Runs on your device without uploading input. Maximum 200,000 characters per field; numeric calculations use finite JavaScript numbers unless exact integer/decimal arithmetic is stated.
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Troubleshooting
Try the small example on this page first. If it works, check your input format and size limit. Save any needed input before reloading. You do not need to share a file or password to report an issue.