Aztec Code Generator
The code on a train ticket or a mobile boarding pass. Aztec needs no quiet zone around it, so it fits into layouts where other 2D codes will not.
The finder is a bullseye at the center rather than squares at the corners, which is what removes the margin requirement and lets the code sit flush against the edge of a ticket. Read off a phone, the variable that decides whether it scans is usually screen brightness rather than size.
- Rail and transit tickets
- Airline boarding passes
- Mobile ticketing
- Tightly-set label layouts
Preview
Enter content to generate Aztec
About Aztec
High-density 2D code that needs no quiet zone, so it fits where other codes will not. Common on transport tickets and boarding passes.
Any text
What is Aztec Code?
Aztec Code is a 2D symbol built outwards from a bullseye finder pattern at its center. Because that finder is in the middle rather than at the corners, the scanner locates the symbol without needing blank space around it. Aztec requires no quiet zone at all. That is the reason it dominates ticketing: a code can be set flush against the edge of a rail ticket or a phone screen and still read.
Technical characteristics
- Symbol
- 15×15 to 151×151 modules, built around a central bullseye
- Capacity
- Up to about 3,000 alphanumeric or 3,832 numeric characters
- Error correction
- Reed–Solomon, selectable from 5% to 95% of symbol capacity
- Quiet zone
- None required
- Orientation
- Read at any angle
The bullseye, and why it needs no margin
Every other two-dimensional code finds itself from its edges. A QR decoder hunts for three corner squares; a Data Matrix decoder looks for a solid L. Both need clear space outside the symbol, because the pattern they are matching is a run of dark and light that a neighboring object would corrupt.
Aztec puts its finder in the middle: concentric square rings at the center of the symbol, with the data built outward around them. Nothing at the boundary is load bearing, so nothing outside it can interfere, and the code needs no quiet zone at all. That single property is why it ended up on tickets, where a code sits flush against a perforation or the edge of a screen.
Reading off a phone at a barrier
A gate scanner sees a code held at an angle, on a screen of unknown brightness, by somebody already walking. Aztec suits that better than most: it is compact for the data it holds, so the modules stay large, and it reads at any rotation.
- Screen brightness matters more than anything you control. A dimmed screen loses contrast before it loses sharpness, which is why ticket apps ask to turn it up.
- Keep the ticket artwork behind the code plain. Aztec tolerates a busy border, but not a pattern showing through the symbol itself.
- Test on a phone with automatic brightness switched on, in a dim room. That is the real condition, and it is not the one a design review happens in.
Choosing how much error correction
Where a QR code offers four fixed levels, Aztec lets you ask for a percentage across a wide range, and the usual default sits around a quarter of the symbol. More correction means a larger symbol for the same content, in the same trade every format makes.
For a ticket printed on thermal stock and shoved in a pocket, spending some of that range is worthwhile. For one displayed on a screen and never touched, the default is generous already.
Aztec Code FAQs
Why do train tickets use Aztec?
Two reasons: it needs no quiet zone, so it fits a cramped ticket layout, and it reads reliably off a phone screen at an angle, which is most of what a barrier scanner sees.
Aztec or QR?
Aztec is more compact for the same data and needs no surrounding blank space. QR is far more widely recognized by consumer software. Transport ticketing tends to Aztec; anything a member of the public scans themselves tends to QR.
What format does the download come in?
Aztec codes download as PNG, rendered at a whole number of pixels per module so the symbol stays sharp at the size you chose.
Why does it not need a quiet zone?
Because it finds itself from the middle rather than the edges: the bullseye at the centre is the finder pattern, so a scanner locates the symbol without needing clear margin around it. That is the property that gets it onto crowded tickets and phone screens, where a QR code would need empty space it does not have.