GTIN / UPC / EAN Barcode Validator
DataValidate UPC-A, EAN-8, EAN-13, and GTIN-14 barcode numbers with GS1 checksum verification. Paste any retail barcode number to instantly check it.
Reviewed by the thecalcu.com team ยท Last updated July 30, 2026
What is a GTIN/UPC/EAN?
A GTIN / UPC / EAN Barcode Validator checks whether a retail product barcode number is correctly formed by verifying its built-in check digit. GTIN (Global Trade Item Number) is the umbrella standard GS1 uses for all of these formats, UPC-A (the 12-digit code standard in North America), EAN-8 and EAN-13 (8 and 13-digit codes used internationally), and GTIN-14 (used for shipping cartons and cases). Every one of these formats embeds a check digit calculated from the other digits, which makes it possible to catch a mistyped or corrupted number without needing to look it up anywhere.
This validator detects which format you've entered based on its length, recalculates the expected check digit, and tells you immediately whether the number is valid. It complements the ISBN Validator, since ISBN-13 numbers are themselves EAN-13 barcodes using the same underlying checksum.
Why Use a GTIN / UPC / EAN Barcode Validator?
Barcode numbers get mistyped surprisingly often, when entering them manually into a spreadsheet, a product catalogue, or an inventory system, a single transposed digit produces a number that looks plausible but doesn't correspond to any real product. Catching that error immediately, before it propagates into a database or a print order, saves significant cleanup work later.
This validator catches exactly that kind of error in seconds. An ecommerce seller importing a product feed with hundreds of UPC codes can spot-check suspicious entries instantly, the same way the JSON Validator helps catch structural errors in a data file before it's used downstream.
Who Should Use This Validator?
- Ecommerce sellers and inventory managers verifying UPC or EAN codes before listing products on a marketplace.
- Retail and supply chain professionals checking GTIN-14 codes used on shipping cartons and cases.
- Developers building product catalogue or POS systems who need to validate barcode input before storing it.
- Data entry teams double-checking barcode numbers transcribed from packaging, spreadsheets, or scanned documents.
- Anyone debugging a barcode scanning issue who wants to quickly rule out a malformed number as the cause.
What Insights Does the GTIN / UPC / EAN Barcode Validator Give You?
The validator tells you two distinct things about the number you enter:
- Format detection, based on the digit count, it identifies whether you've entered EAN-8, UPC-A, EAN-13, or GTIN-14.
- Checksum result, confirms whether the embedded check digit matches what the GS1 algorithm expects, and shows the exact expected value if it doesn't.
Importantly, a passing result confirms the number is correctly formed according to the GS1 standard, it does not confirm the number has actually been registered to a real product, since that requires querying GS1's official database directly.
How to use this GTIN/UPC/EAN calculator
- Enter the barcode number in the Barcode Number field, spaces and hyphens are stripped automatically.
- Read the result card to see whether the checksum passed or failed.
- If it failed, check the details breakdown to see the expected check digit versus what you entered.
- Compare the number against the original packaging, label, or source database to find and fix the discrepancy.
- Re-enter the corrected number to confirm it now passes.
Show formula & methodology โShow less โ
Formula & Methodology
All GS1 barcode formats use the same check digit algorithm, regardless of total length: Check Digit = (10 โ (ฮฃ weighted digits mod 10)) mod 10 where each digit (excluding the check digit itself) is weighted 3 if its position counting from the right is odd, and 1 if even. Worked example: for the UPC-A number 036000291452, the payload is 03600029145 and the check digit is 2. - Weighting from the right: 5ร3 + 4ร1 + 1ร3 + 9ร1 + 2ร3 + 0ร1 + 0ร3 + 0ร1 + 6ร3 + 3ร1 + 0ร3 = 58 - Check digit = (10 โ (58 mod 10)) mod 10 = (10 โ 8) mod 10 = 2 โ matches Invalid example: 036000291450 fails, because the expected check digit is 2, not 0.
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