How WiFi QR codes handle special characters, hex SSIDs, and error correction

WiFi QR codes follow an informal convention originated by ZXing, not an official standard, which means edge cases can cause silent failures across different devices. Passwords containing characters like semicolons or colons must be escaped with a backslash, or naive string parsers will misread the credentials. SSIDs made entirely of hexadecimal characters — such as '5060' or 'deadbeef' — must be wrapped in double quotes to prevent readers from interpreting them as raw hex bytes. Error correction level H, while offering greater damage tolerance, significantly increases QR code density and can make printed codes harder to scan from a distance. For most wall-mounted network signs, lower error correction levels are sufficient, and password length only meaningfully increases code size beyond roughly 12 characters.