QR Code Guides
Reference material for how QR codes actually behave. The rule across all of it: any number here was produced by this site's own encoder and read back by a decoder, or it is labelled as arithmetic or as somebody else's published figure.
The Other Guide Sections
Problems with a specific code belong in troubleshooting. Choosing between symbologies or between static and dynamic is comparisons. Anything about size, material or ink is in the printing guides.
Guides worth reading
- ReferenceOffline QR generators by deviceWhat each platform already ships, the measured cost of each payload type, and how to check an offline claim yourself.
- ReferenceGoogle Business QR codesThe free code Google gives you, the six addresses that all point at your business, and the measured cost of encoding the wrong one.
- ReferenceBest offline QR scannersWhen the built-in camera is enough, when an app earns its place, and the measured reason screenshots fail.
- ReferenceDo QR codes expire?Why static codes cannot expire, and what actually stopped working.
- ReferenceWi-Fi QR codes offlineWhat your device already does, with five first-party sources, and the payload decoded back to prove it.