QR code vs Aztec code

Aztec codes place their finder bullseye in the centre and need no quiet zone, which suits cramped tickets - airline boarding passes under the IATA BCBP standard and many rail tickets use Aztec. QR codes need a four-module margin but hold more data and are read natively by every phone camera.

The comparison

	QR code	Aztec code
Standard	ISO/IEC 18004	ISO/IEC 24778
Origin	Denso, Japan, 1994	Welch Allyn, USA, 1995
Finder	Three corner squares	Single bullseye, dead centre
Quiet zone	4 modules every side	None required
Sizes	21 × 21 to 177 × 177	15 × 15 to 151 × 151
Max capacity	7,089 numeric / 2,953 bytes	3,832 numeric / 1,914 bytes
Error correction	Four levels: 7 / 15 / 25 / 30%	Tunable, roughly 5–95%
Orientation	Any angle	Any angle
Phone camera support	Universal, native	Inconsistent on stock cameras

Aztec's party trick: no quiet zone

A QR code demands a blank margin of at least four modules on every side: miss it and detection fails, a failure common enough to have its own troubleshooting page. Aztec needs none, because its bullseye finder sits in the middle of the symbol and the decoder reads outward from it, never touching the edges.

On a boarding pass or thermal-printed rail ticket (narrow paper, dense text, every millimetre contested) that margin is real estate. It is a large part of why the transport industry adopted Aztec: the IATA Bar-Coded Boarding Pass (BCBP) standard specifies Aztec, QR and Data Matrix for mobile passes, and Aztec became the common choice for airline apps. Many European rail operators, Deutsche Bahn among them, print Aztec on tickets for the same reason.

Aztec's error correction is also unusually flexible: rather than QR's four fixed levels, the generator chooses almost any redundancy percentage, letting ticket systems tune robustness precisely.

Where QR wins

Readers. The infrastructure scanning boarding passes (airport gates, train conductors' devices) is purpose-built and reads Aztec happily. Stock phone cameras are another matter: QR is the only 2D symbology you can rely on a random consumer's camera app to recognise. Publish an Aztec code on a poster and most of your audience will point, wait, and give up.

Capacity and ecosystem. QR holds substantially more data at the top end, supports structured append and kanji mode, and carries the world's payment, WiFi and contact-card conventions. Every generator, including UseQR's, and every decode pipeline is built around it.

Which to use

You operate both ends (issue tickets and control the scanners) → Aztec is a fine, compact choice, and the aviation and rail standards may require it.
The public scans with their own phones → QR code, always.
Space is tight but readers are yours → Aztec's zero quiet zone or Data Matrix's one-module margin both beat QR's four, the quiet zone requirements page has the geometry.

FAQ

What is the difference between an Aztec code and a QR code?

An Aztec code has a single bullseye finder at its centre and requires no quiet zone, while a QR code has three corner finder squares and needs a four-module blank margin. They are separate ISO standards with incompatible decoders.

Why do boarding passes use Aztec codes?

The IATA BCBP standard permits Aztec, QR and Data Matrix, and Aztec's lack of a quiet zone plus centre-out decoding suits small screens and cramped thermal prints. Airport scanners are built to read all the permitted formats.

Can a phone scan an Aztec code?

Dedicated apps and Google Lens generally can, but stock camera apps are inconsistent about Aztec. For anything the general public scans with their own phone, a QR code is the reliable choice.

Does an Aztec code hold more than a QR code?

No. Aztec tops out around 3,832 digits or 1,914 bytes, against QR's 7,089 digits or 2,953 bytes. Aztec's advantage is compactness in constrained print, not capacity.