How Barcode Validation Works
Every EAN and UPC barcode encodes a checksum digit as its last digit. This check digit is computed from the preceding digits using a weighted alternating multiplication (weights 1 and 3) and a modulo-10 sum. When you scan or enter a barcode, the check digit is recalculated from the other digits and compared against the stored value — if they match, the barcode is valid; if not, the barcode is corrupted or mistyped. BarcodeFinder's validator performs this calculation instantly and reports whether your barcode number is valid.
Supported Barcode Formats
- EAN-13: The 13-digit global standard for retail products sold worldwide; includes a GS1 country prefix, manufacturer code, item code, and check digit.
- UPC-A: The 12-digit standard used in North American retail; equivalent to an EAN-13 with a leading zero.
- ISBN-13: The 13-digit International Standard Book Number used to identify books; always starts with 978 or 979.
- EAN-8: A compact 8-digit variant of EAN-13 designed for small product packaging where a full EAN-13 barcode would not fit.