UPC-A Barcode Generator
Generate and validate 12-digit UPC-A retail barcodes.
What is a UPC-A barcode?
UPC-A is the 12-digit barcode used on retail products across North America. It encodes a manufacturer code and product number, with a final check digit that guards against scan errors.
How to create one
Enter 11 digits and we calculate the 12th check digit automatically, or enter a full 12-digit code and we verify it. The tool blocks non-numeric input and shows the check-digit math so you can see exactly how the final number is formed.
How the check digit works
UPC-A uses a modulo-10 checksum: digits in odd positions are weighted by 3 and even positions by 1, the weighted sum is taken, and the check digit is whatever makes the total a multiple of 10. Our results panel shows the entered digits, the calculated check digit and the full number.
Generating vs registering
This tool produces a correct, scannable barcode image. It does not assign or register an official product number. Genuine retail UPCs are issued by GS1; to sell through major retailers you need a number allocated to your company.
Scanning and printing tips
Print UPCs in black on white at their standard size, keep the light margins on each side, and avoid stretching. Test with a real scanner before committing to a print run.
Limitations
A generated image is not a substitute for an official GS1 number. Resizing too small or recoloring can make the barcode unreadable.
Frequently asked questions
Does this register an official UPC?
No. It creates a valid, scannable barcode image. Official retail UPC numbers are issued by GS1 to your company.
What if I only have 11 digits?
Enter 11 digits and the tool calculates and appends the correct 12th check digit for you.
Why was my 12-digit code rejected?
The check digit did not match. The tool shows the correct check digit so you can fix it.
Curious how we build and check these codes? Read our methodology.