QR code glossary · Formats and payloads
WiFi QR code
Also called: Wi-Fi QR code, WIFI: URI
Definition
A WiFi QR code is a QR code that contains a network’s name, password and security type in the WIFI: text format, such as WIFI:T:WPA;S:Cafe Guest;P:espresso-2026;;, so a phone that scans it can offer to join the network without typing the password.
How it works
The code holds one line of text made of fields, each ending with a semicolon, with one more semicolon at the end:
| Field | Meaning | Values |
|---|---|---|
T | Security type | WPA, WEP or nopass for an open network |
S | Network name (SSID) | Exactly as broadcast; capitals and spaces count |
P | Password | Left out for an open network |
H | Hidden network | Optional; true if the name is not broadcast |
A backslash, semicolon, comma, colon or double quote inside the name or password is escaped with a backslash, so the password pa;ss is written pa\;ss. Password-protected WPA2 and WPA3 networks normally use T:WPA; Android can also write T:SAE for WPA3-only networks.
The format began in the open-source ZXing barcode project, modeled on MECARD. It has since been registered with IANA as the provisional wifi URI scheme, which points to section 7 of the Wi-Fi Alliance’s WPA3 specification for its definition. Current iPhone and Android camera apps recognize it.
Why it matters
A WiFi code is always static: the phone needs the credentials themselves, not a link, so it cannot be tracked or edited, and changing the password means printing a new code. Anyone who can photograph the code has the password, so put guests on a separate guest network rather than the one your payment terminal and office computers use.
Escaping is where codes most often go wrong, because generators and phones do not all handle special characters the same way. If the name or password contains any of the reserved characters, test the printed code on an iPhone and an Android phone. Printing the network name and password as text beside the code helps people whose phones will not join automatically.
Example
WIFI:T:WPA;S:Cafe Guest;P:espresso-2026;; is 41 characters and fits a version 3 code (29 × 29 modules) at error correction level M.
In CirculateQR
The free WiFi generator builds the code in your browser, so the password is not sent to a server, and escapes all five reserved characters. WiFi codes are always static, free and never expire.
Related terms
- Static QR codeA static QR code is a QR code whose content, such as a web address, WiFi login or contact card, is encoded directly in the printed pattern, so it works without any service in between but cannot be edited or tracked after it is generated.
- Encoding modesEncoding modes are the ways a QR code packs characters into bits: numeric mode for digits, alphanumeric mode for a 45-character set of capital letters, digits and a few symbols, byte mode for any data such as UTF-8 text, and kanji mode for Japanese Shift JIS characters.
- Data capacityData capacity is the most content a QR code can hold, which depends on its version, error correction level and encoding mode; the largest code, version 40 at level L, holds 7,089 numeric digits, 4,296 alphanumeric characters, 2,953 bytes or 1,817 kanji characters.
- vCard QR codeA vCard QR code is a QR code that contains contact details in vCard format, the standard text format for electronic business cards, so that scanning it makes a phone offer to save the name, phone number, email and other fields as a new contact.
- QuishingQuishing (QR code phishing) is a phishing attack that uses a QR code to send people to a malicious website, typically a fake login or payment page, often by sticking a fraudulent code over a genuine one or by putting a code in an email where link filters cannot inspect it.
Learn more
- Free WiFi QR code generator: Made in your browser; no sign-up.
- How to make a WiFi QR code: Security types, escaping and printing tips.
- Guest WiFi QR codes: Codes for cafés, hotels and rentals.
Sources
Last updated . Written by the CirculateQR team; technical facts follow the sources listed above. Example codes and sizes are computed with the open-source qrcode encoder that CirculateQR uses. Spotted something wrong? Email support@circulateqr.com. QR Code is a registered trademark of DENSO WAVE INCORPORATED.
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