Free barcode generator for your own products

No, and no free generator can give you a code that you can. Retailers and marketplaces require a GTIN registered to you, which means buying a prefix from GS1. What is here is the range GS1 sets aside for use inside one business - the same thing a supermarket uses on weighed goods - so it is right for your own shelves and wrong for somebody else's.

Any EAN-13 scanner will, including a phone camera. They are ordinary EAN-13 barcodes with a correct check digit; the only thing that makes them "in-store" is which numbers they start with. Print them at actual size - "fit to page" shrinks them, and a barcode printed small does not scan.

The sheet is laid out for Avery L7160, which is 63.5 by 38.1 millimetres, three across and seven down, and is sold in every stationer. Any label sheet with that grid works, whoever made it.

Only to you. They are sequential from a fixed prefix, so two products made a minute apart get adjacent codes and a printed sheet reads in order. There is no information hidden in them and nothing is looked up anywhere: the barcode is a name, and what it means lives in whatever you use to keep your stock.

Every code here starts with 21, one of the in-store prefixes, and the thirteenth digit is a check digit. Take the first twelve digits, add the ones in odd positions, then add three times the ones in even positions. The check digit is whatever brings that total up to the next multiple of ten. A scanner does the same sum as it reads, so a smudged or mistyped code is refused instead of being read as a different product.