QR code guides
What to know before you make and print a QR code, with sources and the date we last checked.
- Do QR codes expire? Static vs dynamic codesThe QR image never expires; dynamic codes that route through a provider can stop. How trials switch codes off, how to spot one, and what to do if printed.
- WiFi QR codes: format, special characters and hidden networksA WiFi QR code holds one line like WIFI:T:WPA;S:name;P:pass;; How password symbols are escaped, hidden and open networks, iPhone and Android, and sign tips.
- QR code print size: how big should it be?Close-up QR codes: at least 2 cm (0.8 in) wide, scanning from about 10 times their width. A size table, dense codes, quiet zone and sticker sheets.
- QR code with a logo: error correction, size and contrastA logo works thanks to error correction and uses up part of it. Error correction levels, logo size, and the 2:1 and 4:1 contrast rules of our scan check.
- vCard QR codes: what goes inside and how it savesA vCard QR code stores contact details as text; phones offer to add the contact when scanned. The lines stored, how fields add density, and print tips.
- How to scan a QR code safely: check the link before you open itQR scams send people to fake login or payment pages. Read the real domain before opening a scanned link: where to look and the warning signs.