The history of the QR code.

In the early 1990s, Japanese car factories were drowning in barcodes. A barcode held only 20 or so characters, so a single box of parts could carry as many as ten of them, each scanned one by one.

In 1992 a two-person team at Denso, led by Masahiro Hara and working in the barcode business that is now Denso Wave, set out to build something better. The idea came over a lunchtime game of Go: black and white stones on a grid could carry far more information than a row of lines.

After a year and a half of work, Denso Wave announced the QR code in 1994. It could hold roughly 7,000 digits and be read more than ten times faster than other codes, from any angle. The name says what it was built for: QR stands for Quick Response.

“Having to read so many barcodes in a day was very inefficient…”

In August 2002, Sharp’s J-SH09 for the carrier J-Phone went on sale: the first mobile phone that could read QR codes. Point the camera at a code and the phone opened a website or saved a coupon.

Japan took to it fast. Through the 2000s codes appeared in magazines, on posters, on product packaging and on tickets, and by the end of the decade they ran across the side of buildings in Tokyo.

Outside Asia, almost nobody noticed. Phones there had no reader built in, and the code stayed a curiosity that travellers photographed in Shibuya.

In September 2017 Apple shipped iOS 11, and the iPhone’s own Camera app began recognising QR codes automatically. No app to find, no app to install: point the camera, tap the banner that drops down.

Android followed. In May 2018 Google announced that Google Lens would be built into the camera app on phones from many makers, and scanning a code became something every new smartphone simply did.

Businesses that now relied on codes wanted more from them. Dynamic codes put a short link inside, so the destination could change after printing and every scan could be counted.

On 13 February 2022, during Super Bowl LVI, Coinbase ran a one-minute ad that was nothing but a colourful QR code bouncing around a black screen, like an old DVD player’s screensaver. Its landing page took more than 20 million hits in one minute, and the company briefly had to throttle traffic.

In June 2023, AI-generated QR codes painted in anime and ink-brush styles went viral on Reddit. They looked like art, but not all of them scanned reliably on every phone.

“historic and unprecedented”