Scan EAN-13 and validate the check digit

The leading digits form the GS1 prefix assigned to a national GS1 organisation. Then comes the company's item reference, and the final digit is the check digit. It is computed from the first twelve digits with a weighted modulo-10 algorithm; any mismatch means the code was printed or generated incorrectly.

The scanner recomputes the digit itself and flags the result as valid or invalid. It also shows the prefix country and the exact symbology: EAN-13, EAN-8, UPC-A, UPC-E, ITF-14 or ISBN. That is enough to judge whether a label or a shop image is plausible.

EAN-13 and UPC-A are both GTIN formats; EAN-8 is the compact variant for small packaging. ITF-14 carries the GTIN-14 of a carton, and ISBN-13 is formally an EAN-13 with prefix 978 or 979. The scanner detects all of these families and labels them correctly.

We deliberately do not attach a product database: free sources are incomplete and licensing is unclear. Instead you get the reliable facts — number, check digit, prefix country — and decide where to research further.

The decoder is JavaScript running in your browser. Camera frames are drawn into a canvas and read there; uploaded images are read through FileReader. There is no upload endpoint for image data. That is an architectural decision, not a slogan: the application has no route that accepts image content.

To improve the tool we store anonymous counters only — detected format, payload category (Wi-Fi, product code and so on), interface language, and whether decoding succeeded. No decoded content, no filenames, no IP-based profiling. Scan history lives in your browser’s localStorage and is deleted with one click.

For retail and logistics the code has to be printable and compliant. Our label generator produces EAN, UPC, GS1-128, Data Matrix and VDA 4902 labels as PNG or SVG from the same number you just scanned, closing the gap between checking and producing.