What is an EAN-13?

The barcode on nearly every product sold outside North America. Thirteen digits, the first two or three of which say which country's numbering authority issued the rest. Its clever part is invisible: there is only room for twelve digits in the symbol, so the thirteenth is carried by varying the encoding of the left-hand six - the pattern itself is the extra digit.

What it holds

Twelve digits, or thirteen if the check digit is already on the end. The check digit is arithmetic, not a choice: give us twelve and we work out the thirteenth; give us thirteen that do not add up and we say so rather than printing a barcode that scans as the wrong product.

Making a lot of them

Drop a .txt or .csv on this page and every line becomes its own EAN-13, all of them zipped together. A CSV is read from its first column. Nothing is uploaded - the codes are drawn in this page, on your machine - so a list of five thousand costs nothing and takes as long as your laptop takes.