You may have encountered a square barcode affixed to a graffiti-covered light pole or printed on the reverse side of a business card.

This pixelated square is known as a QR code. QR codes facilitate tasks such as downloading applications, providing contactless access to restaurant menus, and enhancing marketing campaigns through billboards, websites, and social media channels, promoting products and special offers.

Although developed in the mid-1990s, QR codes truly gained traction with the rise of smartphones. These mobile devices enabled a broader and more versatile use of QR codes, creating a convenient, contactless method for accessing and sharing information—particularly valuable during the pandemic.

Here’s an overview of QR codes.

What is a QR code?

The QR code was created in 1994 by Masahiro Hara, who served as the chief engineer at Denso Wave, a subsidiary of Toyota based in Japan. Its initial application focused on tracking vehicles and components as they progressed through manufacturing stages.

QR stands for Quick Response, and these codes are a type of barcode that can be easily scanned by digital devices, such as smartphones. Unlike traditional barcodes, which can only be read in a single direction (top to bottom), QR codes contain information encoded in a matrix of pixels arranged in a square grid, allowing for multi-directional reading—both vertically and horizontally.

These codes are capable of storing approximately 7,000 numeric characters or around 4,000 alphanumeric characters, including symbols and punctuation. They can encode various types of information, such as phone numbers and URLs. The configuration of a QR code adjusts based on the specific data it holds, resulting in a unique arrangement of its black modules.