Technology
How do QR codes work?
A QR code is a square barcode that stores information as a pattern of black and white squares. A camera reads the pattern, and software decodes it into data — usually a web link — letting your phone act on it instantly.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how QR codes works.
Step by step
- 1Data is encoded in a 2D grid of black and white squares.
- 2Three corner squares help the camera orient and align it.
- 3It includes error correction, so it still scans if partly damaged.
- 4Most commonly it stores a URL your phone opens.
Frequently asked questions
- How does a phone read a QR code?
- The camera captures the pattern, and software locates the alignment markers and decodes the squares into data.
- What information can a QR code hold?
- Usually a web link, but also text, contact details, Wi-Fi credentials, or payment info.
- Why do QR codes still work when slightly damaged?
- They include built-in error correction, so part of the code can be missing and still decode.