Aztec code vs QR code

How to tell them apart

Look for the finder pattern, the shape a scanner looks for first:

• Aztec code: one square bullseye in the middle, made of nested rings. The ISO abstract for the Aztec standard describes symbols that are "nominally square, made up of square modules on a square grid, with a square bullseye pattern at their centre".
• QR code: three large squares in the top-left, top-right and bottom-left corners. Denso Wave, which invented the QR code, designed these markers so a reader can find the code and its angle from any direction.

If you see three corner squares, it's a QR code. If you see one target in the middle, it's almost certainly Aztec.

The standards behind each

Both are published international standards, so any manufacturer can build readers and printers for them.

• Aztec Code is defined by ISO/IEC 24778. The current edition is the second, published in April 2024; it replaced the 2008 edition. ISO says it covers how characters are encoded, error correction, the symbol's structure, sizes and print quality, and a reference decoding method.
• QR Code is defined by ISO/IEC 18004, approved in June 2000 according to Denso Wave. Denso Wave holds a patent on the QR code but says it has waived its rights for standardised QR codes, which is a big part of why the format spread.

How much they hold and how they cope with damage

QR codes come in 40 versions, from 21 × 21 to 177 × 177 modules. Denso Wave's specification summary gives a maximum of 7,089 digits or 4,296 alphanumeric characters, with four error correction levels that can restore roughly 7%, 15%, 25% or 30% of the data.

The ISO abstract for Aztec Code says its symbols "can encode from small to large amounts of data with user-selected percentages of error correction". So instead of four fixed levels, the system that makes the code picks how much of it goes to error correction. The full capacity tables are in the paid ISO document, so we don't repeat figures here we couldn't check.

There's also a difference in spacing. Denso Wave says a standard QR code needs a clear margin, called the quiet zone, of at least four modules round it. Keep that border clear when you place a QR code next to text or artwork.

Where you'll see each one

Aztec codes show up mostly where tickets are scanned at gates:

• Wallet passes. Apple's pass format lists Aztec, QR, PDF417 and Code 128 among the barcode formats a pass can use. Google Wallet's API also lists Aztec and QR as barcode types, though only QR and PDF417 can be used for its rotating barcodes.
• Travel and event tickets. A ticket issuer picks the format that its gate scanners read. If your boarding pass or rail ticket shows a bullseye code, that was the issuer's choice, not yours.

QR codes are the default for almost everything a member of the public scans: menus, posters, payments, Wi-Fi, business cards and product packaging. Apple's iPhone guide, for example, says the Camera app reads QR codes on its own, which is why they're the safer choice for anything you print for customers.

Which one should you use?

• Printing something for the public to scan with a phone: a QR code. People know what it is and camera apps open it straight away.
• Building a ticket or pass system: use whatever your scanners, wallet provider or industry rules expect. Apple's and Google's wallet formats accept both, and the issuing software makes the code for you.
• Tight spaces or unusual shapes: look at QR variants too. Denso Wave also publishes Micro QR (at most 17 × 17 modules) and rMQR, a rectangular code for narrow spaces.

Make a QR code

The generator below makes standard QR codes, not Aztec codes. Type a link or text, check it scans with your phone, and download it as PNG or SVG. It runs in your browser and doesn't need an account.

Related guides

• QR code vs barcode
• How do QR codes work?
• How to scan a QR code