GTIN, UPC & EAN Barcode Validator (Check Digit)

Check GTIN, UPC, EAN and ISBN barcode numbers before you upload a product feed to Amazon, Google Merchant Center, Walmart, Shopify or eBay. The GTIN, UPC & EAN Barcode Validator recalculates the GS1 check digit, finds leading zeros lost in spreadsheets, scientific notation like 4.00638E+12, in-store and coupon codes, GS1 demo and unassigned prefixes, placeholder numbers and the same GTIN on different products. It also converts every valid code to GTIN-14, GTIN-13 and UPC-A, expands UPC-E and turns ISBN-10 into ISBN-13. Click Start with the prefilled example to see it work.

This is a structure check: check digit, length and GS1 prefix rules. A valid result does not prove GS1 issued the number or that it belongs to this product or brand; confirm ownership with Verified by GS1 or the brand owner. Every row carries this disclaimer.

What does the GTIN, UPC & EAN Barcode Validator do?

• ✅ Check digit: the GS1 mod-10 check for GTIN-8, UPC-A (GTIN-12), EAN-13 and GTIN-14, and the mod-11 check for ISBN-10. Wrong check digits show the expected digit.
• ✅ Spreadsheet damage: 11-digit UPCs and 12-digit EANs that lost a leading zero, scientific notation (4.00638E+12) that destroyed the last digits, and letters or symbols mixed into the number.
• ✅ Prefix meaning: the GS1 prefix range and country or use (for example 003 UPC-A compatible, 978 books), with flags for in-store/restricted codes (02, 20-29), coupon and receipt ranges, the 952 demo prefix and unassigned prefixes.
• ✅ Placeholder numbers: all-same digits, sequences like 123456789012 and other fill-ins that marketplaces reject.
• ✅ Duplicates across your feed: the same GTIN (after padding to 14 digits) on rows with different IDs or titles, which Amazon and Google treat as an error.
• ✅ Conversions: gtin14, gtin13 and upcA for each valid code, UPC-E expanded to UPC-A, ISBN-10 converted to its 978 ISBN-13.
• ✅ Output per code: status (valid / valid with warnings / invalid), type, checkDigitValid, expectedCheckDigit, prefix, prefixMeaning, issues (code, severity, message, sourceUrl, fixHint), notes, checkedAt and a disclaimer.

Who is it for?

• Marketplace sellers and agencies fixing feed errors before Amazon, Walmart or Google Merchant Center rejects listings.
• Shopify and WooCommerce store owners cleaning barcodes exported to spreadsheets.
• Data and scraping teams validating GTIN fields in scraped product data before matching products across sites.
• Price comparison and catalog sites that join products on GTIN and need clean keys.

How to validate GTIN and UPC codes

1. Click Start with the prefilled example (seven codes with common feed mistakes).
2. Paste your codes into Codes only, or use Products with gtin (or upc, ean, barcode, isbn) plus optional id, title and url to get duplicate checks by product.
3. Or enter a Dataset ID from a Shopify, Amazon, Walmart or other product scraper. Common fields are found automatically; use Field map with dotted paths (for example variants.0.barcode) for nested ones.
4. Turn on Only save rows with findings to skip clean codes; you only pay for saved rows.
5. Export the results as CSV, Excel or JSON, or fetch them through the API.

Input example

This is the prefilled input:

{
  "products": [
    {
      "id": "SKU-1",
      "title": "Example valid UPC-A",
      "gtin": "036000291452"
    },
    {
      "id": "SKU-2",
      "title": "Example wrong check digit",
      "gtin": "036000291453"
    },
    {
      "id": "SKU-3",
      "title": "Example lost leading zero (11 digits)",
      "gtin": "36000291452"
    },
    {
      "id": "SKU-4",
      "title": "Example spreadsheet scientific notation",
      "gtin": "4.00638E+12"
    },
    {
      "id": "SKU-5",
      "title": "Example in-store (restricted) code",
      "gtin": "2012345678903"
    },
    {
      "id": "SKU-6",
      "title": "Example duplicate of SKU-1",
      "gtin": "0036000291452"
    },
    {
      "id": "SKU-7",
      "title": "Example ISBN-10",
      "gtin": "0-306-40615-2"
    }
  ]
}

Dataset mode:

{"datasetId": "YOUR_DATASET_ID", "fieldMap": {"gtin": "variants.0.barcode", "id": "sku", "title": "title"}, "onlyFlagged": true, "maxItems": 10000}

Output example

Real output from a run of the prefilled input on 2026-10-30 (long finding lists are shortened here; the run returns all of them):

[
  {
    "itemNo": 1,
    "productId": "SKU-1",
    "title": "Example valid UPC-A",
    "url": null,
    "input": "036000291452",
    "digits": "036000291452",
    "type": "UPC-A (GTIN-12)",
    "checkDigitValid": true,
    "expectedCheckDigit": "2",
    "gtin14": "00036000291452",
    "gtin13": "0036000291452",
    "upcA": "036000291452",
    "prefix": "003",
    "prefixMeaning": "UPC-A compatible - United States",
    "status": "valid with warnings",
    "issues": [
      {
        "code": "duplicate_gtin_in_run",
        "severity": "medium",
        "message": "The same GTIN appears on 3 rows with different IDs or titles (also on: SKU-3, SKU-6).",
        "sourceUrl": "https://sellercentral.amazon.com/help/hub/reference/external/G200317470",
        "fixHint": "Each distinct product (size, color, pack count) needs its own GTIN; variants can't share one."
      }
    ],
    "notes": [],
    "issueCount": 1,
    "checkedAt": "2026-10-30T18:52:05+00:00",
    "disclaimer": "Structure check only: GS1 check digit, length and prefix rules. A valid result does not..."
  },
  {
    "itemNo": 2,
    "productId": "SKU-2",
    "title": "Example wrong check digit",
    "url": null,
    "input": "036000291453",
    "digits": "036000291453",
    "type": "UPC-A (GTIN-12)",
    "checkDigitValid": false,
    "expectedCheckDigit": "2",
    "gtin14": "00036000291453",
    "gtin13": "0036000291453",
    "upcA": "036000291453",
    "prefix": "003",
    "prefixMeaning": "UPC-A compatible - United States",
    "status": "invalid",
    "issues": [
      {
        "code": "bad_check_digit",
        "severity": "high",
        "message": "Check digit is 3, but GS1's formula gives 2.",
        "sourceUrl": "https://www.gs1.org/services/how-calculate-check-digit-manually",
        "fixHint": "Usually a typo or a copied/made-up number. Take the code from the physical barcode or the brand owner."
      }
    ],
    "notes": [],
    "issueCount": 1,
    "checkedAt": "2026-10-30T18:52:05+00:00",
    "disclaimer": "Structure check only: GS1 check digit, length and prefix rules. A valid result does not..."
  },
  {
    "itemNo": 3,
    "productId": "SKU-3",
    "title": "Example lost leading zero (11 digits)",
    "url": null,
    "input": "36000291452",
    "digits": "36000291452",
    "type": "UPC-A (GTIN-12), leading zero missing",
    "checkDigitValid": true,
    "expectedCheckDigit": "2",
    "gtin14": "00036000291452",
    "gtin13": "0036000291452",
    "upcA": "036000291452",
    "prefix": "003",
    "prefixMeaning": "UPC-A compatible - United States",
    "status": "valid with warnings",
    "issues": [
      {
        "code": "leading_zero_lost",
        "severity": "medium",
        "message": "11 digits: this looks like a UPC-A whose leading 0 was dropped (with the 0 restored, the check digit is valid).",
        "sourceUrl": "https://support.google.com/merchants/answer/6324461",
        "fixHint": "Store it as text with the leading zero: 036000291452."
      },
      {
        "code": "duplicate_gtin_in_run",
        "severity": "medium",
        "message": "The same GTIN appears on 3 rows with different IDs or titles (also on: SKU-1, SKU-6).",
        "sourceUrl": "https://sellercentral.amazon.com/help/hub/reference/external/G200317470",
        "fixHint": "Each distinct product (size, color, pack count) needs its own GTIN; variants can't share one."
      }
    ],
    "notes": [],
    "issueCount": 2,
    "checkedAt": "2026-10-30T18:52:05+00:00",
    "disclaimer": "Structure check only: GS1 check digit, length and prefix rules. A valid result does not..."
  },
  {
    "itemNo": 4,
    "productId": "SKU-4",
    "title": "Example spreadsheet scientific notation",
    "url": null,
    "input": "4.00638E+12",
    "digits": null,
    "type": null,
    "checkDigitValid": null,
    "expectedCheckDigit": null,
    "gtin14": null,
    "gtin13": null,
    "upcA": null,
    "prefix": null,
    "prefixMeaning": null,
    "status": "invalid",
    "issues": [
      {
        "code": "spreadsheet_scientific_notation",
        "severity": "high",
        "message": "'4.00638E+12' is in scientific notation, so the spreadsheet has already rounded away the last digits.",
        "sourceUrl": "https://support.google.com/merchants/answer/6324461",
        "fixHint": "Re-export the column formatted as text; the original digits can't be recovered from this value."
      }
    ],
    "notes": [],
    "issueCount": 1,
    "checkedAt": "2026-10-30T18:52:05+00:00",
    "disclaimer": "Structure check only: GS1 check digit, length and prefix rules. A valid result does not..."
  },
  {
    "itemNo": 5,
    "productId": "SKU-5",
    "title": "Example in-store (restricted) code",
    "url": null,
    "input": "2012345678903",
    "digits": "2012345678903",
    "type": "EAN-13 (GTIN-13)",
    "checkDigitValid": true,
    "expectedCheckDigit": "3",
    "gtin14": "02012345678903",
    "gtin13": "2012345678903",
    "upcA": null,
    "prefix": "201",
    "prefixMeaning": "Used to issue GS1 restricted circulation number within a geographic region",
    "status": "valid with warnings",
    "issues": [
      {
        "code": "restricted_circulation",
        "severity": "medium",
        "message": "Prefix 201 is for restricted circulation (in-store or internal numbers), not a global product ID.",
        "sourceUrl": "https://www.gs1.org/standards/id-keys/company-prefix",
        "fixHint": "Marketplaces expect the brand owner's GTIN; store-issued codes are often rejected."
      }
    ],
    "notes": [],
    "issueCount": 1,
    "checkedAt": "2026-10-30T18:52:05+00:00",
    "disclaimer": "Structure check only: GS1 check digit, length and prefix rules. A valid result does not..."
  },
  {
    "itemNo": 6,
    "productId": "SKU-6",
    "title": "Example duplicate of SKU-1",
    "url": null,
    "input": "0036000291452",
    "digits": "0036000291452",
    "type": "EAN-13 (GTIN-13)",
    "checkDigitValid": true,
    "expectedCheckDigit": "2",
    "gtin14": "00036000291452",
    "gtin13": "0036000291452",
    "upcA": "036000291452",
    "prefix": "003",
    "prefixMeaning": "UPC-A compatible - United States",
    "status": "valid with warnings",
    "issues": [
      {
        "code": "duplicate_gtin_in_run",
        "severity": "medium",
        "message": "The same GTIN appears on 3 rows with different IDs or titles (also on: SKU-1, SKU-3).",
        "sourceUrl": "https://sellercentral.amazon.com/help/hub/reference/external/G200317470",
        "fixHint": "Each distinct product (size, color, pack count) needs its own GTIN; variants can't share one."
      }
    ],
    "notes": [],
    "issueCount": 1,
    "checkedAt": "2026-10-30T18:52:05+00:00",
    "disclaimer": "Structure check only: GS1 check digit, length and prefix rules. A valid result does not..."
  },
  {
    "itemNo": 7,
    "productId": "SKU-7",
    "title": "Example ISBN-10",
    "url": null,
    "input": "0-306-40615-2",
    "digits": "0306406152",
    "type": "ISBN-10",
    "checkDigitValid": true,
    "expectedCheckDigit": null,
    "gtin14": "09780306406157",
    "gtin13": "9780306406157",
    "upcA": null,
    "prefix": "978",
    "prefixMeaning": "Book (ISBN converted to ISBN-13 / EAN-13)",
    "status": "valid",
    "issues": [],
    "notes": [
      "Converted ISBN-10 to its 978 ISBN-13, which is the barcode number marketplaces expect."
    ],
    "issueCount": 0,
    "checkedAt": "2026-10-30T18:52:05+00:00",
    "disclaimer": "Structure check only: GS1 check digit, length and prefix rules. A valid result does not..."
  }
]

How much does it cost to validate barcodes?

This Actor uses pay-per-event pricing: $0.0005 per code saved plus a $0.00005 start fee per run, plus small platform usage paid by you (a few hundredths of a cent for small runs). That's about $0.50 for 1,000 codes and $5 for 10,000 codes plus usage. With Only save rows with findings on, valid codes aren't saved or charged. You can set a maximum cost per run in the run options.

Use it through the API, integrations or AI agents

• Run it and get results in one call: https://api.apify.com/v2/acts/ultimatemc~gtin-barcode-validator/run-sync-get-dataset-items
• Use it from AI agents through the Apify MCP server: https://mcp.apify.com?tools=ultimatemc/gtin-barcode-validator
• Schedule it after a daily scraper run, send flagged rows to Slack or email with webhooks, or connect it to Make, Zapier, n8n or Google Sheets.
• Chain it after a product scraper by passing the scraper's dataset ID.

How it works

Validation is fully deterministic and runs offline: the GS1 check digit formula, the length rules of the GS1 General Specifications and a built-in GS1 prefix table, checked on 2026-10-30. No barcode database is queried, so it's fast and cheap, but it can't tell you who owns a number. Duplicates are found by padding every valid code to GTIN-14 and comparing rows in the same run.

Sources:

• GS1: How to calculate a check digit manually
• GS1 General Specifications
• GS1 Company Prefix
• Verified by GS1
• Amazon Seller Central: Product UPCs and GTINs
• Google Merchant Center: GTIN
• International ISBN Agency: What is an ISBN?

FAQ

Does "valid" mean the barcode is real and mine?

No. It means the number has the right length, check digit and prefix structure. Marketplaces also check GS1 ownership; use Verified by GS1 to confirm who licensed a number.

Why is my 11-digit UPC flagged?

Spreadsheets often drop the leading zero of a UPC-A. If adding the zero gives a valid check digit, the row is marked leading_zero_lost and the corrected code is shown.

Can it fix scientific notation like 4.00638E+12?

No. That format has already lost the last digits, so the original number can't be recovered. Re-export the column as text.

Does it look up product names?

No. It doesn't call any barcode database, which keeps it fast and costs at $0.0005 per code.

Is it AI?

No. It's a fixed set of GS1 rules, so results are repeatable.

Limitations

• Ownership isn't checked; a correctly formed number can still belong to someone else.
• The GS1 prefix table is built in and reflects GS1 published ranges as of 2026-10-30.
• Duplicates are only detected within one run.
• Codes damaged by scientific notation can't be repaired.

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Found a wrong result? Open an issue on the Issues tab with the code and what you expected, and we'll review the rule.