UPC-A barcode generator
UPC-A is the twelve-digit code on the back of almost everything sold in a North American shop. Eleven digits identify the company and the item; the twelfth is a check digit derived from the other eleven. The field here wants all twelve, and eleven produces no symbol, but the check digit is computed regardless: give it eleven digits and the status line returns the full number with the twelfth in place, ready to paste back in.
Appearance
340 × 244 px in the PNG
Specification
- Character set
- digits
- Length
- exactly 12 characters
- Check digit
- calculated automatically by the encoder
Generate UPC-A barcodes in bulk
Got a whole list of values rather than one? Generate UPC-A barcodes in bulk
Where it is used
- Retail packaging aimed at the United States and Canada, where checkout systems still expect twelve digits rather than thirteen
- Online marketplace listings that refuse to publish a product page until a valid GTIN is supplied
- Reprinting a barcode that has rubbed off an existing pack, where the number itself is known and only the symbol has to be redrawn
- In-store labels built on the restricted number-system digits 2 and 4, which GS1 leaves to the retailer and which mean nothing outside that shop
How it compares
UPC-A and EAN-13 are the same symbol wearing different numbers. Put a zero in front of a UPC-A and you have a valid EAN-13; strip a leading zero from an EAN-13 and you have the UPC-A back. Both are 95 modules of bars plus 18 modules of quiet zone — 113 in total, 37.29 mm at full size — and both use the same mod-10 check digit with alternating weights of 3 and 1. The split is regional, not technical: North American retail settled on twelve digits, the rest of the world on thirteen. Any scanner built for EAN-13 reads UPC-A without being told to; the risk runs the other way, since older equipment built strictly around twelve digits sometimes refuses a thirteen-digit number.
Common mistakes
- Inventing your own number. The generator draws whatever digits you give it, but the right to print a particular number on a product for sale comes from a company prefix licensed from GS1 — a number you made up may already belong to another manufacturer.
- Adding a thirteenth digit as a check digit. In UPC-A the check digit is the twelfth digit; it is part of the number, not something appended to it.
- Shrinking the symbol to fit the space left on the artwork. The standard runs from 80% to 200% magnification: at 100% a module is 0.33 mm and the symbol is 37.29 mm wide, so 80% and a 0.264 mm module is the floor, not a suggestion.
- Printing the bars in red or orange. Laser scanners read with a red beam, and red bars on a white background reflect it almost as well as the paper does, so the symbol reads as a blank label.
Frequently asked questions
- Do I have to buy a prefix before I can use this barcode?
- For anything sold through retail, yes. Bars are only an encoding of a number, and the right to use a specific number comes from a GS1 company prefix that you licence. Nothing is registered for a code that never leaves your own warehouse — and for that kind of internal use Code 128 is usually the better symbology anyway, since it takes letters too.
- What if I only know the first eleven digits?
- Eleven digits draw nothing, and the status line prints the complete twelve with the check digit worked out, ready to paste back. The branch worth knowing is the other one: type all twelve with the last digit wrong and the same line names the digit that belongs there instead. That is the branch you want when you are checking a number read off an imported pack rather than computing a new one.
- What does the first digit mean?
- It is the number system character. General trade items normally begin with 0, 1, 6, 7 or 8, drug products in the United States use 3, and 2 and 4 are reserved for a retailer's own in-store codes — a 2-prefixed code on a pack of cheese is priced by weight inside one chain and means nothing at the shop next door.
- Can I put a UPC-A on a pack that ships worldwide?
- You can, and it will scan, because a UPC-A is simply an EAN-13 whose leading digit is zero. Whether you should depends on the buyer: some trading partners outside North America want the thirteen-digit form printed on the pack even though both encode the same item.
Prefix registration
This generator draws a valid UPC-A symbol, but the image alone does not grant the right to sell a product under it in retail. The prefix is issued by GS1 — register it there before printing this code on packaging.