Real barcodes, with the check digits done right
A barcode is not a picture of stripes — the last digit of a retail code is a checksum the scanner verifies, and a generator that guesses it produces labels that beep error at the till. This tool validates each format properly (powered by the JsBarcode library): enter 12 digits for EAN-13 and the 13th check digit is computed for you; enter all 13 and it is verified. The same care applies to UPC-A and ITF-14, and CODE39 rejects characters it cannot legally encode, with a clear message instead of a silently broken barcode.
How to use it
- Pick the format your scanner, marketplace or warehouse expects.
- Type the value. The hint under the field states exactly what the format accepts, and errors explain themselves.
- Style it: bar width and height, colours, value text on or off.
- Download PNG for documents and labels, or SVG for print and design tools — SVG scales forever without softening.
Which format do I need?
EAN-13 / UPC-A are for retail products and need numbers issued by GS1 if the products will be sold in shops — this tool formats and checks the digits, it cannot issue official numbers. CODE128 is the flexible default for internal labels (assets, SKUs, shelf edges). ITF-14 marks outer cartons. CODE39 is the old, widely-supported warehouse format. MSI survives in library and warehouse niches.