UPC-A Barcode Generator
UPC-A is the twelve-digit retail barcode of the United States and Canada — the original checkout symbol, in continuous use since 1974. Enter 11 digits and the tool computes the check digit (and tells you); enter all 12 and it verifies yours. The input and check digit are validated by this site's tested logic before rendering, then an independent ZXing decoder confirms the actual SVG bars before the barcode is shown. PNG export is decoded separately before download.
A rendered symbol is not a registered number
Before printing this on anything you plan to sell: UPC numbers are licensed, not generated. Retailers and marketplaces increasingly validate GTINs against theGS1 registry, and a number nobody licensed to you will be rejected — or worse, collide with someone else's product. What this tool legitimately does is render numbers you already have the right to use: GTINs from your GS1 prefix, internal codes for a closed store system, or samples for design mockups.
UPC-A is EAN-13 wearing a shorter coat
The two symbologies share one numbering system (GTIN) and one check-digit algorithm. Worked at build time by this site's engine: data digits 03600029145 require check digit2, giving the complete UPC-A 036000291452 — and its EAN-13 form0036000291452 yields the identical check digit2, because a leading zero adds nothing to the weighted sum. That equivalence is why an EAN-13 generator will accept your UPC with a zero in front, and why scanners report either form interchangeably.
The mod-10 check, from the UPC side
In UPC terms: add the digits in the odd positions (first, third, fifth…), triple that sum, add the digits in the even positions, and the check digit is whatever lifts the total to a multiple of ten. It is the same 3-and-1 weighting as EAN-13, just described from the other end — both are anchored at the rightmost data digit, which always carries weight 3.
Print size and quiet zones
GS1 size guidance calls for light margins of at least 9 module widths on each side of a UPC-A symbol (GS1 size guide). The downloads include those quiet zones. Beyond the margins, the advice is qualitative but firm: print dark bars on a light background, do not scale below the sizes your print process can hold cleanly, and test the result with a real scanner — the supermarket laser is the only judge that counts.
UPC-A FAQ
How many digits do I enter?
Eleven or twelve. With 11 digits the tool computes the 12th (the check digit) and says so; with 12 it verifies your last digit against the first eleven and reports any mismatch instead of silently accepting it.
Is UPC-A different from EAN-13?
A UPC-A number is a 12-digit GTIN. Put a zero in front and you have its 13-digit EAN form — same product, same check digit, and EAN-capable scanners worldwide read both. UPC-A remains the conventional symbol on North American packaging.
Where do real UPC numbers come from?
From GS1. Companies license a GS1 company prefix (in the US, via GS1 US) and allocate product numbers under it. A generator can render any mathematically valid 12 digits, but only licensed numbers identify products in retail systems.
Why does my scanner read out 13 digits for a UPC-A?
Many scanners normalize every retail symbol to GTIN-13 form by prefixing a zero. The barcode is unchanged; the scanner is just reporting the same number in its 13-digit form.
Is anything I type sent anywhere?
No. Validation, check-digit math, and rendering run entirely in your browser; nothing is transmitted or stored.
Verify before production: mathematics checked here, optics checked by your scanner — always test the printed symbol. Everything runs locally in your browser; see themethodology page. Numbering items that never leave your own store? Thein-store barcode guide explains number system 2 and 4 prefixes.