QR Code

A QR code (for Quick Response Code) is a kind of two-dimensional barcode that can store various types of information, including text, URL links, etc. A QR-code is made up of black and white squares arranged in a square pattern.

To create a QR-code, use the dCode form at the top of this page.

As a developper, to code a QR-code program, a QR code uses the ISO norm 18004:2015 (QRCode).

To read QR-Code, a quick and free solution is a mobile phone. Many smartphones automatically detect QR codes and offer a link to open. Else use Google Lens here (which is integrated into the Google search bar)

Without smartphone, on Internet:

dCode recommends QRazyBox here to read, analyze and edit QR codes

A QR Code is distinguished by its pattern of 3 black squares in its corners of a larger square. It is often surrounded by a white margin. It can also contain identifying elements, such as a company logo, but the basic pattern of black and white dots (or 2 distinct colors) remains unchanged.

The two letters QR in QR Code stands for Quick Response.

A QR code has no time limit (no lifespan), nor a maximum number of uses. However, if the data contained in the QR code has a lifetime (like an address of a web page) then the QR code will still exist even if the web page no longer exists.

The center of the QR-Code is sometimes non-coding and therefore used to incorporate a logo. Otherwise, there are many other 2D barcodes like DataMatrix (FlashCode), Aztec, PDF 417, etc.

The storage capacity of a QR Code depends on its version and the level of error correction, but it can store up to a few thousand characters.

It is not possible to exceed this maximum limit, on dCode or elsewhere.

A barcode is linear, meaning it consists of parallel bars next to each other. The data is encoded according to the width of the black and white bars and quite limited in terms of storage capacity.

A QR Code is two-dimensional, meaning it is made up of black and white squares arranged in a square pattern. This provides greater storage capacity.

QR codes incorporate error-correcting data, allowing them to be read even if they are damaged or partially obscured.

QR Codes can be created in color, but QR Code scanners are designed to read black and white codes. Colors are often used for aesthetic or branding reasons, but it is important to maintain adequate contrast for reliable reading.

QR codes themselves are safe and pose no risk. However, a QR code containing a link can take the user to a malicious website.

The QR Code was invented in 1994 by a Japanese company called Denso Wave.