What Is a QR Code and How Does It Work?
Understand QR symbols, payloads, error correction and the difference between storing text and linking to a website.
A small symbol with structured data
A QR code is a machine-readable arrangement of dark and light modules. Its payload may be plain text, a website address or an action string that a compatible app recognizes. The symbol does not contain the website itself when it holds a URL: the reader still needs to fetch that destination.
Why the surrounding border matters
The corner finder patterns help a reader orient the symbol. A blank quiet zone helps it locate the boundaries against nearby text and artwork. Cropping off that border or stretching one axis makes the recognition task harder. Preserve both the module grid and the surrounding space in your design.
Error correction has limits
Error correction adds redundancy, allowing some damaged symbols to be read. It is not permission to cover arbitrary parts of a code. A logo can hide important patterns, and a code that works in a pristine preview may fail on a reflective sign.
Try a controlled comparison
Generate a short text code and a URL code. Decode both without opening a link and compare the returned payloads. Then test a longer message to see how density increases. This makes the relationship between data length, symbol density and practical scan size easier to understand.
Try the related tool
Open QR Code Generator and use a harmless example for your first test.