Technology
How does a QR code work?
A QR code works by storing data as a grid of black and white squares that a camera reads as binary 1s and 0s. Special corner patterns let the scanner find and orient the code, then decode the pattern into text, a link, or other information.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how a QR code works.
Step by step
- 1Each black or white module represents a bit, so the grid encodes binary data.
- 2Three large corner squares let a scanner locate and align the code at any angle.
- 3Built-in error correction lets it still scan even if part is dirty or damaged.
- 4Software decodes the pattern into a URL, text, payment info, or Wi-Fi details.
- 5It holds far more than a 1D barcode because it stores information in two dimensions.
Frequently asked questions
- Can a QR code still scan if it's partly damaged?
- Often yes. QR codes include error correction that can rebuild up to about 30% of missing data, depending on the level used.
- Why do QR codes have three big squares?
- Those 'finder patterns' let the scanner instantly detect the code's position and orientation, so it reads correctly from any angle.
- Are QR codes safe to scan?
- The code itself is just data, but it can hide a malicious link — check the URL before opening, just as you would any link.