The History of 2D Barcodes

The history of 2D barcodes is a story about running out of room. The humble striped barcode was a triumph, but it could only hold a handful of digits. As industries demanded more, engineers asked a bold question: what if a code used both dimensions of the page at once? The answer reshaped how we track almost everything. 🐾

Why did we need 2D barcodes at all?

A traditional one-dimensional barcode, like the UPC on a cereal box, stores information only in the widths of its vertical stripes. That gives it a hard ceiling of roughly a dozen or two characters, usually just a product number that a computer looks up elsewhere. Our piece on 1D vs 2D barcodes lays out the contrast in full.

By the 1980s, that was not enough. Manufacturers wanted to encode entire part descriptions, shipping details or lot numbers directly on tiny components, without relying on a distant database. The only way to pack in more data was to stop wasting the vertical axis and use it too. The 2D barcode was born from that pressure.

How does stacking data into two dimensions work?

There are two broad approaches to two dimensions. Some codes stack multiple rows of a 1D-style barcode on top of one another. Others build a true matrix, a grid of tiny black and white cells read in both directions at once.

Moving from one dimension to two is not a small tweak. It multiplies capacity dramatically, letting a symbol the size of a postage stamp hold hundreds or thousands of characters.

Matrix codes, in particular, could shrink to a few millimetres and still carry meaningful data, which made them ideal for marking small industrial parts. To make them robust, designers leaned heavily on error correction, the mathematics we cover in Reed-Solomon error correction.

What was Data Matrix?

Data Matrix emerged in the late 1980s and early 1990s and remains one of the most widely used 2D codes in industry. It is a compact square (or rectangle) of cells with a distinctive solid "L" shape along two edges, called the finder pattern, that tells a scanner where the code begins and how it is oriented.

Data Matrix excels at marking very small items: electronic components, surgical instruments and aerospace parts often carry one just a few millimetres across. Because it packs a lot of data into a tiny footprint, it is still the go-to code for direct-part marking today. We compare it head to head with QR in QR code vs Data Matrix.

What about Code 49 and PDF417?

Not every 2D code is a neat square. Several important formats took the stacked approach, layering rows of bars.

Code 49

Code 49, developed in the late 1980s, was one of the early stacked symbologies, cramming several rows of barcode-like data into a small label to break past the 1D capacity limit.

PDF417

PDF417 was created by Symbol Technologies in the early 1990s. It stacks many rows of a specialized pattern and can hold a large amount of data, over a thousand characters, in a rectangular block. You have almost certainly used one without knowing: PDF417 appears on the back of many driver's licences, on shipping labels and on boarding passes. Our guide to Aztec codes and PDF417 goes deeper.

How did MaxiCode and Aztec add new ideas?

Two more codes pushed the design further.

Code	Origin	Notable trait
MaxiCode	UPS, early 1990s	Fixed size with a bullseye center for fast sorting
Aztec	1995	Bullseye finder in the middle, no quiet zone needed

MaxiCode was developed by UPS to sort and track parcels at high speed on conveyor belts. Its distinctive central bullseye lets scanners lock onto it quickly even as packages rush by at odd angles.

Aztec, created in 1995, also uses a central bullseye pattern. A clever advantage is that it needs no blank "quiet zone" around it, so it can be printed in tighter spaces. Aztec is common on train and event tickets to this day.

Where does the QR code fit in?

Into this crowded field arrived the QR code in 1994, invented by Masahiro Hara's team at Denso Wave to track automotive parts. It was not the first 2D barcode, but it struck an unusually good balance: high capacity, very fast reading from any angle thanks to its three corner finder patterns, and strong error correction. Read the full story in the invention of the QR code.

Crucially, Denso Wave chose not to enforce its patents against standard-compliant users, so the format was effectively free. Combined with its versatility, that openness helped QR outgrow its industrial roots and become the 2D code the public actually recognizes. It was later enshrined as the open standard ISO/IEC 18004.

Why did QR win the public while others stayed niche?

Data Matrix, PDF417 and Aztec are all excellent, and each still dominates its niche: tiny part marking, official documents, transit tickets. But QR became the household name for a few reasons.

1. It read fast from any orientation, ideal for casual scanning.
2. It was free to use and openly standardized.
3. It scaled from tiny stickers to giant billboards.
4. It arrived just in time for smartphones to make scanning effortless.

The other 2D codes did their jobs quietly and well, while QR stepped into the spotlight. If you would like to make one for yourself, you can create a free QR code in a few clicks, and see how the winner of the 2D race actually behaves.

Frequently asked questions

What is the difference between a 1D and 2D barcode?

A 1D barcode stores data only in the widths of vertical stripes and holds little information. A 2D barcode uses both dimensions, packing far more data into the same space.

What was the first widely used 2D barcode?

Data Matrix and stacked codes like PDF417 arrived in the late 1980s and early 1990s, making them among the earliest 2D symbologies in broad industrial use.

What 2D barcode is on a boarding pass?

Boarding passes typically use PDF417 or Aztec codes rather than QR codes, both of which are well suited to carrying ticket data reliably.

Who invented MaxiCode?

UPS developed MaxiCode in the early 1990s to sort and track packages at high speed, using a distinctive central bullseye pattern.

Why did the QR code become more popular than other 2D codes?

It read quickly from any angle, was free to use and openly standardized, scaled to almost any size, and arrived just as smartphones made scanning effortless.