Barcode Validator & Check Digit Calculator

Calculate check digits, catch format problems and pass a valid value straight to the generator.

Validate

Check a barcode value or build standards-aware GS1 data.

No lookup required

Barcode value Format

For EAN, UPC or GTIN, enter the complete value to verify it or omit the final digit to calculate it. Spaces and hyphens are ignored for those standards.

Your validation result appears here.

Processed locally. Values and check-digit calculations stay in this browser.

Validate barcode structure without a product lookup

Check EAN, UPC and GTIN check digits, plus supported Code 128, Code 39 and ITF rules. Exact expected and received check digits are shown for deterministic corrections.

Check a complete code

Compare a supplied final digit with the locally calculated one.

Calculate a final digit

Enter data digits without the check digit to create a complete value.

Build GS1 data

Use structured fields for supported GS1-128 and GS1 Data Matrix output.

Separate structural checks from real-world identity

Choose a format or use Auto, then enter the source value exactly as supplied.

For EAN, UPC or GTIN, inspect the calculated check digit and any expected-versus-received mismatch.

Apply a Fix only when the intended data digits are known and the final digit is the deterministic error.

Send the reviewed value to the generator, then test the rendered and physical code in its receiving system.

What each validation result establishes
Check	It can establish	It cannot establish
EAN, UPC or GTIN checksum	Correct length, digits and check-digit arithmetic for the selected standard.	Product identity, allocation, ownership or authenticity.
Code 128 or Code 39	Whether the value uses characters accepted by the local encoder.	That a receiving application expects that symbology.
ITF	Numeric content and the required even number of digits.	A retail or logistics meaning not present in the data.
Round-trip decode	That the current digital render decodes to the intended value in the local verifier.	Performance on every printer, material, camera or scanner.

Worked example: review a deterministic correction

Format: EAN-13
Input: 4006381333933
Expected check digit: 1
Corrected value: 4006381333931

Validate reports the check-digit mismatch rather than silently generating a different value. The final digit can be corrected deterministically, but a mistyped data digit cannot be inferred from the checksum. Compare the source record before using Fix, then send the reviewed value to Create. Structural validity does not prove that an identifier is allocated, genuine or associated with the intended product.

Specifications

Retail checks

EAN-13, EAN-8, UPC-A and GTIN-14 check digits.

Other formats

Code 128 printable ASCII, Code 39 characters and ITF numeric/even-length rules.

Boundary

Validation checks structure; it does not confirm product ownership or authenticity.

Barcode Validator & Check Digit Calculator

Validate

Validation result