How WiFi QR Codes Actually Work

The format behind the code

Every WiFi QR code encodes a string in this structure:

T is the encryption type, S is the network name (SSID), P is the password, and H marks whether the network is hidden. When a phone's camera reads this pattern, it recognizes the WIFI: prefix and offers to join the network directly. No app, no typing.

Choosing the right encryption type

The code has to match your router's actual security setting, or the connection attempt fails:

• ▸WPA — covers WPA and WPA2, the standard on almost every router sold since the mid-2010s. This is the correct choice for the vast majority of home and business networks.
• ▸WEP — an older, weaker standard. Only use this if your router's admin page specifically shows WEP as the active security type, which is rare today.
• ▸No password — for open networks with no encryption at all, common in some public or guest networks.

You can find your network's type in your router's admin panel, usually under a "Wireless Security" or "WiFi Settings" section.

What "hidden network" changes

If your network doesn't broadcast its name (SSID), mark the code as hidden. This tells the connecting phone to actively search for a network with that exact name instead of just picking it from a visible list. Without this flag set correctly, a hidden network's QR code may fail to connect even with the right password.

Why it sometimes still doesn't connect

A WiFi QR code can scan correctly and still fail to connect. The usual reasons:

• ▸Enterprise networks requiring a username and certificate (common in offices and universities) aren't supported by the WIFI: format at all. Only personal WPA/WEP networks work.
• ▸A captive portal (the login page some hotel and café WiFi shows in a browser) still requires that extra step after connecting. The QR code only handles the WiFi handshake, not the portal login.
• ▸A typo in the password field when generating the code produces a code that scans fine but connects with the wrong credentials, so double-check the password matches your router exactly, including case.

Creating your WiFi QR code with oh my qr

Select WiFi, enter your network name and password, pick the matching encryption type, and mark the network as hidden only if it actually is. Print the result near your router or at your venue's entrance so guests connect without ever seeing the password in plain text.