QR code guides

Short, plain answers to the questions people ask before and after they print a code.

• Do QR codes expire?A QR code itself never expires. Static codes work forever, but dynamic codes stop when a trial or plan ends. How to check yours, and fix one that stopped.
• How to scan a QR code on iPhone and AndroidScan a QR code with your iPhone or Android camera, no app needed. Plus how to scan a code from a screenshot or photo, and what to do if nothing happens.
• Is it safe to scan a QR code?Scanning a QR code is usually safe; the risk is the link it opens. How to read the preview, spot fake codes and what to do if you scanned a bad one.
• QR code size for printingHow big to print a QR code: at least 2 cm (0.8 in) up close, about a tenth of the scanning distance further away. Charts for cards, flyers, posters and signs.
• Static vs dynamic QR codesStatic QR codes are free and never expire. Dynamic codes let you edit the link and count scans, but depend on a company. An honest guide to choosing.
• Why won't my QR code scan?Why your QR code won't scan: contrast, size, missing white border, logo, glare or a dead link. Quick checks to find the cause, and fixes for printed codes.

Or go straight to the QR code maker.