What is a scan code?
A scan code is any printed pattern a camera or scanner can read and turn back into data. There are two broad kinds. One-dimensional barcodes, like the EAN and UPC codes on retail products, store a short number in a row of black bars of different widths. Two-dimensional codes, like QR codes, store much more in a grid of squares that reads in two directions. This generator makes both, so you can create a QR code for a link or a barcode for a product, label, or ticket, all from one place.
The scan codes you can make
Each type suits a different job. Use the table to match a code to what you need, then pick it in the generator above.
| Type | Kind | Holds | Common use |
|---|---|---|---|
| QR Code | 2D | Text, URLs, Wi-Fi, contacts | Links, posters, menus, payments |
| Code 128 | 1D | Full ASCII, letters and numbers | Shipping, logistics, labels |
| EAN-13 | 1D | 13 digits | Retail products worldwide |
| UPC-A | 1D | 12 digits | Retail products in North America |
| EAN-8 | 1D | 8 digits | Small retail packaging |
| Code 39 | 1D | Digits, A to Z, a few symbols | Industry, ID badges, inventory |
| ITF-14 | 1D | 14 digits | Cartons and shipping cases |
1D barcodes versus 2D codes
The big difference is direction. A 1D barcode is read across a single line, so it holds a small amount of data. A 2D code is read across a grid, so it holds far more in the same space.
| Feature | 1D barcode | 2D code |
|---|---|---|
| Reads in | One direction | Two directions |
| Data amount | Small | Large |
| Holds letters | Some types | Yes |
| Error recovery | Limited | Built in |
| Phone camera reads it | Sometimes | Easily |
QR code data capacity
A QR code holds far more than a 1D barcode. These are the maximums for the largest QR code at the lowest error correction, from the QR Code standard (ISO/IEC 18004). Barcodes hold only a short value, which is why they suit product numbers rather than text.
| Type | Characters |
|---|---|
| EAN-13 | 13 digits |
| UPC-A | 12 digits |
| EAN-8 | 8 digits |
| ITF-14 | 14 digits |
| Code 39 | Variable |
| Code 128 | Variable, full ASCII |
Parts of a barcode
A barcode is more than its bars. The quiet zones and start and stop patterns tell a scanner where the code begins and ends, and a check digit guards against misreads.
How a check digit works
Retail barcodes like EAN-13 end in a check digit, a single number calculated from the others. A scanner recomputes it and rejects the read if it does not match, which catches most mistakes. Here is the calculation for EAN-13.
Why it matters
The check digit is what lets a scanner beep with confidence. A smudge or a misaligned scan that changes one bar usually breaks the check, so the scanner asks for another pass instead of recording the wrong number.
You do not calculate it
This generator adds the check digit for you. For EAN-13 you can enter 12 digits and the 13th is filled in. For UPC-A, enter 11 and the 12th is added.
Real product numbers
To sell a product in shops, the number itself must be issued by GS1, the body that manages retail barcodes. This tool draws the code, but it cannot assign you an official product number.
How to make a scan code
Choose a code type
Pick a QR code or a barcode such as Code 128 or EAN-13 from the menu in the generator.
Enter your content
Type a link or text for a QR code, or the value for a barcode. The helper note shows what each type expects.
Customise it
Set the colours, and for QR codes the error correction and style. Keep strong contrast so it scans.
Test the scan
Point your phone camera at the preview to confirm it reads what you expect.
Download
Save an SVG for print or a high-resolution PNG for screens, then place it where people can scan it.
Best practices for codes that scan
Keep the quiet zone
Leave clear space around a code. Barcodes and QR codes both need an empty margin to read reliably.
Use strong contrast
Dark bars on a light background scan best. Avoid pale colours or reversing the two.
Do not shrink too far
Tiny codes fail. Print at a size the scanner and your audience's distance can handle.
Test before you print
Scan with more than one phone or scanner, and proof a printed sample at final size.
Use SVG for print
Vector files stay sharp at any size, so use SVG for packaging, labels, and posters.
Match code to job
Use a QR code for links and rich data, and a 1D barcode for short product or tracking numbers.
Scan code terms, defined
- Barcode
- A 1D scan code that stores a value in the widths of parallel bars and spaces.
- QR code
- A 2D scan code that stores data in a grid of squares and reads in two directions.
- Symbology
- The standard a barcode follows, such as Code 128 or EAN-13, which sets how data is encoded.
- Quiet zone
- The clear margin around a code that lets a scanner tell where it starts and ends.
- Check digit
- An extra digit calculated from the others that helps a scanner catch misreads.
- GS1
- The organisation that issues the official product numbers used in EAN and UPC retail barcodes.