The history of QR codes

QR codes were invented in 1994 by a team led by Masahiro Hara at Denso Wave, a Toyota subsidiary, to track car parts faster than barcodes allowed. Denso Wave patented the format and then declined to enforce the patents, which is why the format became universal.

1994: the problem being solved

Toyota's production system needed to track components through assembly. Barcodes held about twenty characters, so a single part often carried several, and each had to be scanned separately in roughly the right orientation. Scanning was the bottleneck.

Masahiro Hara's team at Denso Wave set out to build a code that held far more data and could be read fast from any angle.

The finder pattern insight

The hardest problem was making a code findable in an image full of other things. The team analysed printed materials — labels, forms, packaging — looking for a black-and-white ratio that almost never occurs naturally.

They settled on 1:1:3:1:1, the ratio produced by scanning a line through a square inside a square inside a square. That pattern is what lets a scanner find a QR code in a cluttered photograph, at any rotation, in milliseconds.

The licensing decision

Denso Wave filed patents and then publicly declared it would not exercise them against users of the standardised format. That is the single reason QR codes are everywhere and comparable proprietary 2D codes are not.

"QR Code" remains a registered trademark of Denso Wave. The format is described in ISO/IEC 18004, first published in 2000.

The uneven adoption

Japan, 2002 onward. Sharp shipped phones with built-in QR readers. Within a few years codes were on business cards, train tickets, food packaging and adverts.

The West, 2010–2013. A wave of marketing enthusiasm, then a collapse. The reasons were practical: no native camera support, so users needed a separate app; and codes routinely pointed at desktop websites that were unusable on a phone.

China, 2013 onward. WeChat Pay and Alipay made QR the default payment interface for a billion people, in a market that largely skipped cards.

India, 2016 onward. UPI, built on a QR-friendly deep link, did the same at national scale.

Everywhere, 2017–2018. iOS 11 added QR scanning to the camera app; Android followed. The app-install barrier vanished.

2020. Contactless menus made QR codes visible to Western consumers again — the least technically interesting phase, and the one most people remember.

FAQ

Who invented the QR code?

A team at Denso Wave, a Toyota Group subsidiary, led by Masahiro Hara. The format was released in 1994.

Why was the QR code invented?

To track automotive components through assembly. Barcodes held too little data and had to be scanned in the right orientation, which made scanning the bottleneck.

Are QR codes patented?

Denso Wave holds patents but has declared it will not enforce them against users of the standardised format. Using QR codes is free; the name "QR Code" is a trademark.

Why did QR codes take off in Asia first?

Japanese phones shipped with built-in readers from 2002, a decade before Western phones did. In China and India, QR-based payments arrived before card infrastructure was entrenched.