Aztec Code

The Aztec code is built on a square grid with a bullseye pattern at its center for locating the code. The Aztec code contains one or more data layers that store information and check characters. These layers are read in a clockwise direction.

Markers in the corner of the bullseye pattern of an Aztec barcode indicate the direction they should be read. Because these are in the center of the code, this eliminates the need for a quiet zone around the barcode. The Aztec barcode therefore requires less space than some other codes.

The Aztec code has a central square with layers of square pixels of varying sizes. These squares contain encoded data. There are three Aztec code formats: full Aztec code, compact Aztec code, Aztec Rune code.

• Full Aztec code: Has 40 symbol sizes and can encode up to 3067 alphanumeric characters, 3832 numerical characters, and 1914 bytes of data.
• Compact Aztec code: Has four symbol sizes and can encode up to 89 alphanumeric characters,110 numerical characters, and 13 bytes of data.
• Aztec Rune code: The smallest format, which can convey 8 bits of data.

Aztec codes are used widely and appear in many everyday places. For example, your airline boarding pass or rail ticket will likely contain an Aztec code. In fact, IATA BCBP selected the Aztec code as a standard for airline boarding passes. Your Apple wallet also relies on Aztec barcodes to activate mobile payments.

Many industries use Aztec codes to track and manage items including manufacturing, logistics and healthcare. Authorities also use them for tax payments or to validate documents such as car registration documents.

To the untrained eye, QR codes and Aztec codes may seem alike, but their designs and functionality are quite different. QR codes have an easily recognizable square grid of black and white squares, whereas Aztec codes have a unique central bullseye pattern surrounded by concentric squares.

A QR code has a larger data capacity compared to an Aztec code. QR codes can store up to 4296 alphanumeric characters, 7089 numerical characters and 2953 bytes of data. QR codes can also store Kanji characters.

On the other hand, Aztec codes hold up to 3067 alphanumeric characters, 3832 numerical characters, 1914 bytes of data and cannot store Kana or Kanji characters. However, an Aztec code does not require a quiet zone around its edge to ensure reliable scanning (unlike a QR code). It can therefore store more data in a smaller space.

Any smart device with a camera can read the majority of QR codes. However, the more specialist Aztec code will require you to install an app.