QR code

lastmod 2026-03-05created 2021-06-0615 edits

A QR code (Quick Response code) is a computer-generated black-and-white grid pattern code, a matrix-type two-dimensional code that represents information. An earlier two-dimensional code used for a similar purpose is the barcode. As the name suggests, a barcode is simple stick-shaped bars arranged in two dimensions. QR codes are widely used mainly in Korea, Japan, China, the UK, the US, and elsewhere, and the name comes from Denso Wave's registered trademark 'Quick Response'. It is a two-dimensional pattern that overcomes the capacity limit of the widely used barcode and extends its format and content; because it holds information both horizontally and vertically, it can store character data in addition to numbers. It is usually read and used with a digital camera or a dedicated scanner. The National Institute of Korean Language refined the term QR code into 정보무늬 (jeongbo munui, "information pattern").

Categories

• QRCode:Examples:qrscanner - SeAH's POC project for QRCode scanning.

Projects

• Html5-QRCode - A cross platform HTML5 QR code reader
• QRpicture - Make QR codes that look like photos
  • https://www.qrpicture.com/
  • https://github.com/xyzzy/qrpicture
  • https://news.hada.io/topic?id=2680
• zxing - multi-format 1D/2D barcode image processing library implemented in Java
• QR-designer - Open-source QR code designer that lets you add any content to the center area
• python-qrcode - Python QR Code image generator
• libzbar - QR Code scanner engine for QR+Emoji
• zbar-py - zbar package
• pyzbar - Read one-dimensional barcodes and QR codes from Python 2 and 3.
• QReader - Robust and Straight-Forward solution for reading difficult and tricky QR codes within images in Python. Supported by a YOLOv8 QR Segmentation model.
• cv2.QRCodeDetector - Built into OpenCV.
• qrencode (libqrencode)

Encoding without installing anything

Send a request to the web using curl:

# wtfutil QR 서비스 사용 / Use wtfutil QR service
curl "https://wtfutil.com/qr/?url=https://your-url.com"

# 또는 qrcode.show 서비스
curl "https://qrcode.show/https://your-url.com"

See also

• Barcode
• QR Code
• Data Matrix

Favorite site

• Wikipedia (en) QR code
• How to draw a QR code with Qt in native C/C++
• Creating easy-payment QR codes on the client without an internet connection | GeekNews
  • [Original] 🤫It's offline, but it has to be online - locally generated payment tokens

For Library

• libqrencode website
• qtqr: GUI front-end for qrencode made in Python & Qt