The History of the QR Code: From 1994 to Today

The QR code is a two-dimensional matrix barcode released in 1994 by Denso Wave, then a division of the Japanese car-parts maker Denso. An engineer named Masahiro Hara led its development to replace 1D barcodes in manufacturing. It stayed an industrial tool for years before phone cameras made it a consumer habit.

Who invented the QR code, and why?

Masahiro Hara, an engineer at Denso, led a two-person team. According to Denso Wave's account, manufacturing sites asked in 1992 for faster barcode scanning. Each barcode held about 20 characters, so workers scanned as many as roughly 1,000 a day. The finished code took about a year and a half.

The code needed more data per symbol, fast reading from any angle, and tolerance for factory dirt. QR stands for Quick Response: the goal was a code read much faster than the barcodes then in use, as the Denso Wave history describes. A popular story says Hara drew on the board game Go, but that history does not mention it.

How does a QR code work so quickly?

Three square position detection patterns in the corners let a scanner find the code and its orientation without reading the whole image. To choose the shape, the team surveyed fliers, magazines and boxes for the black-to-white ratio that appeared least in print: 1:1:3:1:1. Denso Wave says the finished code could be read more than 10 times faster than other codes.

Reed-Solomon error correction, a method also used for music CDs, rebuilds missing data. According to Denso Wave there are four levels: L (about 7%), M (15%), Q (25%) and H (30%). That is also why a small logo can sit in the centre of a code; see our QR code with logo guide.

Are QR codes patented?

Denso Wave holds the patents but declared it would not exercise them. Its patent page says everyone can use the QR Code freely when following the JIS or ISO standards. "QR Code" remains a Denso Wave trademark.

The standardization timeline shows the steps: AIM International in October 1997, JIS X 0510 in January 1999 and ISO/IEC 18004 in June 2000.

How did QR codes become mainstream?

Removing the install-an-app step was the change that mattered in the West, and the pandemic made scanning routine. Our QR code statistics page covers adoption since, and QR code vs barcode compares the two formats.

What is the QR code today?

Denso Wave keeps extending the format. Its list of QR Code types includes Micro QR, rMQR (rectangular), SQRC (reading-restricted) and Frame QR. The Japan Patent Office notes QR codes have found uses Denso did not expect. For how the structure works, see what is a QR code, or see plans to make your own dynamic codes.