How to use it
- Choose the barcode type.
- Enter your number or text; the check digit is added or verified.
- Adjust height, bar width and whether to show the number.
- Download PNG or SVG (for print).
Barcode types
| Type | Data | Typical use |
|---|---|---|
| UPC-A | 11 digits + check digit | Retail products in the US and Canada |
| EAN-13 | 12 digits + check digit | Retail products worldwide |
| EAN-8 | 7 digits + check digit | Small packages |
| ISBN | 13-digit ISBN (978 or 979) | Books, drawn as an EAN-13 symbol |
| Code 128 | Any ASCII text | Shipping labels, inventory, asset tags |
| Code 39 | A–Z, 0–9, space and - . $ / + % | Industrial and government labels, badges |
For your own inventory, shelf labels or asset tags, Code 128 is usually the best choice: it is compact and encodes letters, digits and symbols. For products sold in stores, you need UPC-A or EAN-13 with a registered number.
Check digits explained
UPC, EAN and ISBN barcodes end with a check digit that lets scanners catch misreads. The generator calculates it when you enter one digit less than the full length (11 for UPC-A, 12 for EAN-13, 7 for EAN-8), or verifies it when you enter the full number.
How the GS1 check digit works, for UPC-A 03600029145:
- Starting from the right, multiply the digits alternately by 3 and 1.
- Add the results: here the sum is 58.
- The check digit is what you add to reach the next multiple of 10: 60 − 58 = 2.
So the full UPC is 036000291452. If you type the full number with a wrong last digit, the tool tells you which digit would be correct.
ISBN barcodes for books
Books carry an EAN-13 barcode built from the 13-digit ISBN, starting with 978 or 979 (the "Bookland" prefix). Hyphens are fine when you enter it: 978-0-… works.
If you only have an older 10-digit ISBN, convert it first: put 978 in front of the first nine digits and calculate a new check digit, because the ISBN-10 check digit uses a different method. The tool will remind you if you enter a 10-digit ISBN.
Many US publishers also print a 5-digit price add-on next to the ISBN barcode for retail. That add-on is not generated here.
Getting a real product barcode
This generator draws a barcode from a number you already have. It does not issue numbers. To sell products through retailers and marketplaces, each item needs a GTIN (the number behind UPC and EAN barcodes) from a company prefix licensed by GS1 US (or the GS1 organization in your country). Retailers check that the number belongs to your company.
For internal uses, such as stock rooms, libraries, events and asset tracking, you can use any numbering you like, ideally with Code 128.
Printing tips
- Download SVG for professional printing and labels; it stays crisp at any size. The PNG is rendered at 4× resolution, which is enough for normal office printing.
- Print black bars on a white background. Colored or low-contrast barcodes often fail to scan.
- Keep the quiet zone, the blank margin on both sides, free of text and graphics.
- Do not squeeze the barcode horizontally; reduce the bar width instead.
- Test the printed label with a scanner app or our barcode scanner before printing a large batch.
Frequently asked questions
How do I make a UPC barcode?
Choose UPC-A and enter the 11-digit number; the check digit is added. Download PNG or SVG.
Is the barcode free to use?
Yes. The image is yours to use. For retail sales, though, the number itself must come from GS1.
Can I use letters in a barcode?
Yes, with Code 128 (any ASCII text) or Code 39 (uppercase letters, digits and a few symbols). UPC and EAN are digits only.
Why does it say my check digit is wrong?
The last digit does not match the GS1 calculation. Check the number, or enter it without the last digit to have it calculated.
Which format is best for printing?
SVG, because it is vector-based and stays sharp at any size.
Last updated: November 12, 2026