A captive portal is a login page in public WLAN networks to restrict Internet access to the approval of certain terms of use. When you see a login page on a public network, your device uses a captive portal check. This allows the device to find out whether you have direct Internet access or not. In Android, for example, your device sends a request to a Google server.
Since mid 2019 I provide a free Captive Portal Check: [https://connectivitycheck.sp-codes.de/generate204](https://connectivitycheck.sp-codes.de/generate204) You are welcome to use it if you like.
## Setup in Android
To change the Captive Portal Check in Android, you need a terminal app or a connection via ADB to a computer.
To use `http` you can run the following commands with the respective method:
```
# settings put global captive_portal_use_https 0
# settings put global captive_portal_http_url "http://connectivitycheck.sp-codes.de/generate204"
```
To use `https` you can use the following two commands:
```
# settings put global captive_portal_use_https 1
# settings put global captive_portal_https_url "https://connectivitycheck.sp-codes.de/generate204"
```
Maybe you have to reboot your phone after updating the settings.
If you are using AFWall+ you need to give access to _[1000] Android-System_ and in some cases _[10040] CaptivePortalLogin_ to make it work.
## Setup in Ubuntu
In Ubuntu, the file `/etc/NetworkManager/NetworkManager.conf` must be changed. Add or change the following lines:
Type [about:config](about:config) in the Firefox address bar and search for `captivedetect.canonicalURL` and `network.connectivity-service`. Set the URL values to `https://connectivitycheck.sp-codes.de/generate204`, the domain values to `connectivitycheck.sp-codes.de`. That's it.
