The history of QR codes

The QR code was designed to be read fast by a factory scanner, not to be pointed at with a phone. Everything that happened afterwards, from Japanese train adverts to pandemic menus, was a use its inventors did not plan. This is the story in order, with a source for every date.

A problem on the production line

In the early 1990s Denso, a Toyota-group parts maker, was labelling boxes of components with ordinary barcodes. One barcode holds about 20 characters, so a single box might carry ten of them and a worker scanned each in turn. Masahiro Hara, an engineer in Denso’s development team, was asked for something better.

Hara’s team was two people. Their target, according to Denso Wave’s own account, was a code that could hold around 7,000 digits, encode kanji as well as numbers, and be read more than ten times faster than the codes of the day. Other companies were also designing two-dimensional codes, but Hara noticed they were all “obsessed with packing as much information as possible” and paid little attention to reading speed.

The speed problem was solved by the three big squares. If the code carried a fixed mark that told the scanner “a code starts here”, the scanner would not have to search the whole image. The team went through printed material of every kind looking for the ratio of dark to light that appeared least often in ordinary print. The answer was 1:1:3:1:1, and that ratio is still what your phone hunts for today. The anatomy article shows where it sits.

The grid of black and white squares itself is often said to come from the board game Go. Hara has told the story himself: he played Go at lunchtime, and the black and white stones on a grid suggested how data could be laid out. IEEE Spectrum has his account.

After about a year and a half of work, Denso announced the QR code in 1994.

Giving it away

A code that only one company could use would never have spread. Denso took two steps that mattered more than any technical feature.

First it put the format into public standards. AIM International published it as ITS 97-001 in October 1997, Japan adopted it as JIS X 0510 in January 1999, and ISO/IEC 18004 followed in June 2000, all recorded on Denso Wave’s standards page.

Second, it promised not to sue. Denso Wave “has waived the rights to a patent in its possession (Patent No. 2938338) for standardized QR Codes only”, in the words of the same page. Anyone could make or read a standard code without paying. The trademark and patents article explains what that means for a business today.

Phones arrive

The QR code left the factory when cameras arrived on phones. The Sharp J-SH09, sold by J-Phone in Japan from August 2002, was the first handset with a built-in QR reader, according to Eurotechnology Japan. Within a few years Japanese magazines, posters and train adverts carried codes as a matter of course.

Denso kept extending the family. Micro QR, a smaller format with a single finder pattern, became a JIS standard in November 2004 (Denso Wave). ISO folded it into the second edition of ISO/IEC 18004 in September 2006. iQR followed in 2008 and Frame QR in 2014. The variants article covers each one.

The slump

Outside Japan the story stalled. Western phones needed a separate app to scan, the apps were poor, and marketers printed codes that led to pages not built for phones. By late 2012 the trade press was writing obituaries; a Forbes piece from December 2012 carried the headline “QR codes are dead”. The myths article looks at how that claim aged.

Asia went the other way. Alipay began QR payments in 2011 and WeChat Pay followed, and within a few years the two apps handled most mobile payments in China (CGAP). India launched Bharat QR in 2017 (Mintoak). The payment QR codes article explains how those systems work.

In June 2014 the European Patent Office gave Hara’s team the Popular Prize at the European Inventor Award, a public vote (Denso Wave).

The turn

Two things changed the Western picture. In June 2017 Apple announced that the iOS 11 camera app would read QR codes with no extra app (TechCrunch). Android makers did the same. The friction that killed the 2012 campaigns was gone.

Then in 2020 the pandemic made touch-free interaction urgent. Menus, venue check-ins, test results and health passes all moved to QR codes within months (International Banker). The habit stuck.

Still moving

The standard is still being worked on. Rectangular Micro QR (rMQR), a wide, thin format for edges of labels, became ISO/IEC 23941 in 2022 (ISO). The fourth edition of ISO/IEC 18004 was published in August 2024 (ISO), and on 25 February 2026 ISO marked that edition “to be revised”, with a working draft, ISO/IEC WD 18004, already registered (ISO). The ISO 18004 article explains what each edition changed.

Full timeline