Barcode Lookup & Validators
Validate UPC, EAN, ISBN and GTIN check digits, calculate the correct check digit from a partial value, and detect the likely format of an unknown barcode — all client-side.
UPC Lookup
Validate any UPC-A barcode, check the trailing check digit, and surface the country / company prefix. Use this for the 12-digit barcodes on US and Canadian retail packaging.
EAN Lookup
Validate EAN-13 (13 digits) and EAN-8 (8 digits) — the global retail standard outside North America. Confirms the check digit and the GS1 country / publisher prefix.
ISBN Barcode Reader
Validate an ISBN-10 or ISBN-13 from a barcode value or book-cover scan. Confirms the check digit, normalises to ISBN-13 and identifies the publisher language prefix.
GTIN Validator
Validate GTIN-8, GTIN-12 (UPC-A), GTIN-13 (EAN-13) and GTIN-14 (ITF-14) in one place. Computes and verifies the GS1 mod-10 check digit and normalises to GTIN-14.
Check Digit Calculator
Paste a UPC, EAN or GTIN body (without the last digit) and get the correct GS1 check digit. Handy when building barcodes from a partial sequence or fixing a typo.
Barcode Type Detector
Paste an unknown barcode value and the detector tells you the most likely symbology (UPC-A, EAN-13, GTIN-14, ISBN, GS1 Digital Link, GS1-128 …) plus what to do next.
About the lookup & validator tools
These tools cover the boring-but-essential second half of a barcode workflow: confirming that the value you scanned, OCR'd or were sent is a real, well-formed identifier — and finishing the value when it's incomplete. Every tool runs in your browser. There is no third-party product database call: we validate the structure (length, character set, country prefix, mod-10 check digit) that the value itself encodes.
Need to look up actual product data behind a verified GTIN? Pair the validator with the wholesaler / retailer feed you're already licensed for. Need to read a barcode first, or generate a new one from a verified value? The reader and generator hubs have you covered.
When to use it
- Confirming a 12- or 13-digit barcode from a supplier feed before sending it to print.
- Validating an ISBN supplied by an author or distributor against the GS1 mod-10 / mod-11 spec.
- Computing the final check digit for a partial GTIN body you pulled out of a planning spreadsheet.
- Triaging an unknown barcode value pulled from a CSV export and figuring out which symbology to expect.
- Cross-checking a UPC-A on a US retail item against the same product's EAN-13 export listing.
- Round-trip-verifying a barcode you just generated — read it back and validate the value with the matching tool.
How it works
- 1Step 1Paste a value
Each tool accepts the raw digits from a scan, a screenshot OCR, a supplier feed or a label-artwork file.
- 2Step 2Pick the right tool
Use the detector if you don't know the format; a format-specific lookup (UPC / EAN / ISBN) when you do; the GTIN validator for cross-format.
- 3Step 3Read the verdict
Tools return validity (pass / fail), the canonical normalised form, the GS1 prefix where it applies, and a one-click copy of the corrected value.
- 4Step 4Fix or finish
If the check digit is wrong, the Check Digit Calculator gives you the right one. If the format is wrong, the detector tells you what it actually looks like.
- 5Step 5Hand off
Take the validated value into a generator, a retailer feed or your inventory system. The tools never store the values you paste.
What to avoid
- Don't treat a valid check digit as proof that a product exists — these tools verify structure, not ownership or retail registration.
- Don't strip leading zeros from a UPC-A before validating — the leading zero is significant for GS1 mod-10.
- Don't pass a GS1 Digital Link URL into the UPC / EAN lookups — use the GS1 Digital Link Decoder instead; the raw URL won't validate as a 12- or 13-digit barcode.
- Don't enter ISBN-10 values into the EAN lookup; ISBN-13 (978 / 979 prefix) is the EAN-13 form — ISBN-10 needs the ISBN reader's mod-11 check.
- Don't assume the Type Detector is authoritative for short numeric values — a 12-digit string could be UPC-A, GTIN-12 or coincidence; verify with the matching validator.
Tips & tricks
- When triaging a batch of unknown barcodes, run them through the Type Detector first, then route to the matching validator — much faster than guessing per value.
- If the GTIN Validator flags a check-digit mismatch, the Check Digit Calculator will show you what the correct final digit should be, often surfacing a single transposed digit upstream.
- ISBN-13 always starts with 978 or 979 — if you see a 13-digit barcode without that prefix, it's an EAN-13 for a non-book product, not an ISBN.
- GTIN-14 with a leading 0 is just a GTIN-13 (EAN-13) right-padded; the validator normalises it so you don't have to.
- Always pair a generator with the matching validator in your QA — generate a code, read it back, validate the value, then sign off the artwork.
Frequently asked questions
- What's the difference between a UPC and an EAN?
- UPC-A is 12 digits and dominant in the US and Canada. EAN-13 is 13 digits and is the worldwide standard everywhere else — including the UK and EU. The two are interchangeable in modern scanners; UPC-A is effectively an EAN-13 with a leading zero. See the UPC vs EAN guide for a deeper comparison.
- Do these lookups go to an external product database?
- No. Every tool runs in your browser. The lookups validate structure (length, prefix, check digit) and surface GS1 metadata that the value itself encodes; we do not call any third-party product database. If you need product names, pair the validated GTIN with the retailer / wholesaler database you're licensed for.
- Is the check digit the same algorithm for UPC, EAN, ISBN-13 and GTIN-14?
- UPC, EAN-13 and GTIN-8/12/13/14 all use the same GS1 mod-10 algorithm — that's why the GTIN Validator handles them in one tool. ISBN-13 is also GS1 mod-10 (it's literally an EAN-13 with the 978/979 prefix). ISBN-10 uses a different mod-11 algorithm with X as a possible check character; the ISBN reader handles both.
- What is the Check Digit Calculator for if the validators already compute it?
- Use the validator when you have a complete barcode and want to confirm it's correct. Use the calculator when you have the first N digits (a partial body, often from a planning spreadsheet or label artwork) and need the final digit to make a real, scannable code.
- Why would I use the Barcode Type Detector?
- You scanned, OCR'd or were sent a raw value but don't know which symbology it came from. The detector heuristically classifies the string (length, character set, GS1 markers, ISBN prefix) so you can route it to the right validator or lookup without guessing.
- Are my entered barcodes logged or sent anywhere?
- No. There is no server-side storage and no analytics on the values you paste — the tools are pure browser code. See the Privacy page for details.
Related tools and guides
Scan a barcode from camera or image and feed the result into a validator on this page.
Generate UPC, EAN, QR, Data Matrix and GS1 Digital Link from a validated value.
Decode GS1 Digital Link URLs and manage barcode inventory lists with CSV export.
Plain-English guide to GTIN-8/12/13/14 and the GS1 mod-10 check digit.
When you'll see each format, and how to convert between them.
Quick-reference table of common 1D and 2D symbologies and their valid value patterns.