A captive portal is the sign-in page that appears after you join a managed Wi-Fi network. When it does not open, the device may look connected while websites remain unavailable.
Quick checks
- Turn off mobile data temporarily so the browser must use Wi-Fi.
- Open a plain HTTP address supplied by your college, or ask IT for the official login URL.
- Disable any VPN temporarily and retry.
- Forget the network, reconnect and accept the portal prompt.
- Check that date and time are automatic and correct.
Check private or randomised addresses
If the college registered one MAC address but the device presents another, access may fail. Compare the address shown in the Wi-Fi network details with the one registered in the college portal. Do not turn privacy features off globally; use a network-specific setting only when campus IT requires a stable address.
Private DNS and encrypted DNS
Some portals need to intercept the first unauthenticated request. Custom DNS, Private DNS or a VPN may interfere. Return to the institution-recommended configuration while signing in, then follow its policy for privacy tools after authentication.
What to send campus IT
- Your device type and operating-system version
- The Wi-Fi network name
- The time of the failed attempt
- Your current Wi-Fi MAC address
- A screenshot of the exact error without exposing your password
Avoid risky shortcuts
Do not copy another student’s address, run packet-capture tools on the campus network or create an unauthorised repeater. These actions can violate policy and make diagnosis harder.