What is inside a Wi-Fi QR code
A Wi-Fi QR code is an ordinary QR code whose text follows a de facto format popularized by the ZXing barcode library and supported by iOS and Android cameras. It is a single line of semicolon-separated fields:
WIFI:T:WPA;S:MyNetwork;P:secret123;;| Field | Meaning |
|---|---|
T | Security type: WPA, WEP or nopass |
S | SSID, the network name |
P | Password (omitted for open networks) |
H | true if the network is hidden (omitted otherwise) |
The string always ends with a double semicolon. The dropdown's "WPA / WPA2 / WPA3" option writes T:WPA, "WEP" writes T:WEP and "None (open)" writes T:nopass and drops the password field.
Escaping special characters
Because ; and : separate fields, they must be escaped inside the SSID and password with a backslash. This tool escapes the backslash itself and also ;, ,, : and the double quote. Take a network called Joe's Cafe; Guest with the password a:b,c\d. The payload becomes:
WIFI:T:WPA;S:Joe's Cafe\; Guest;P:a\:b\,c\\d;;That 45-character payload is encoded at error-correction level M, which fits a version 4 code (33 × 33 modules). The tool fixes the level at M and renders a 256 px PNG or a scalable SVG.
Common mistakes
- Wrong capitalization or spaces. SSIDs and passwords are case sensitive, and a trailing space is part of the name. Copy them exactly from your router page.
- Forgetting the hidden flag. If your router does not broadcast its name and the box is unticked, phones will not find it. Tick "Hidden network" to add
H:true. - Choosing the wrong security type. An open-network code (
nopass) will not supply a password, and a WEP code will fail against a WPA2 router. Check the router's security setting. - Leaving the code in public view. The password is readable by anyone who scans it. For visitors, put the code on a guest network that is isolated from your main devices.
- Not regenerating after a password change. The printed code holds the old password, so it stops working the moment you change it.
Need a stronger router password first? Make one with the password generator. To encode a URL or text instead, use the general QR code generator, which also offers error-correction and size choices.