What a Wi-Fi QR code contains
A Wi-Fi code is an ordinary QR code whose text starts with WIFI: and carries key-value pairs separated by semicolons: T for the security type, S for the network name, P for the password and H:true for a hidden network. A complete example is WIFI:T:WPA;S:Home Office;P:correct horse battery;; with the double semicolon marking the end.
Phone cameras recognise that prefix and offer to join. Android and iOS both support it, and both can share a saved network as a code from their Wi-Fi settings, which is where many of the codes you will meet come from. Some router labels carry one as well.
Reading the decoded fields
The network name is the SSID exactly as the router broadcasts it, including capital letters and spaces. SSIDs are case-sensitive, so copy it rather than retype it when a device asks for it by hand. The security row shows the T value, normally WPA, which in this format stands for WPA, WPA2 and WPA3 alike, or WEP for very old equipment. A code without a T field is treated as open.
Hidden network: Yes means the router does not broadcast the name. A phone that scans the code handles that, but a device you configure by hand will not list the network. You must choose the option to add a network manually and type the SSID. If the code is not a Wi-Fi code at all, the page says so and shows the raw payload with its type instead.
Connecting a device that cannot scan
The usual reason to decode a Wi-Fi code on a web page is a device with no camera: a laptop, a desktop, a smart TV, a printer, a console or a thermostat. Scan the code with your phone here, copy the password, and paste it into the device's Wi-Fi settings, or read it off the screen if the device has no clipboard.
Passwords copied this way avoid the classic typos between l and 1, O and 0, and a trailing space that nobody notices. If the device still refuses to connect, check that it supports the network's band and security type: an old printer may only speak 2.4 GHz and may not support WPA3 at all.
Why some Wi-Fi codes fail on a phone but decode here
This page shows whatever the code contains, while a phone only joins when the payload is well formed. The common faults are a missing final semicolon, a security type written in a form such as WPA2-PSK that some phones do not recognise, and unescaped special characters in the password. Seeing the raw payload (Copy raw) tells you which of these applies.
If a code you generated elsewhere fails, rebuild it with the QR code generator, which writes the standard form and escapes the five reserved characters. Then scan the new code here and compare the decoded password with the one on your router, character by character, before you print it.
What this page cannot do
A web page cannot join a network for you. Browsers have no access to the operating system's Wi-Fi settings, so the result stops at showing and copying the fields. The last step is always done in the device's own settings. It also cannot tell you whether the password is still current, only what was encoded when the code was made.
Treat the decoded password as you would the printed one. Nothing leaves your browser, but if you scanned someone else's code without permission, you now hold their credentials. If you run the network, prefer a separate guest SSID for printed codes and rotate the password when staff or tenants change, reprinting the code each time.