Programming Tips - Detect unfiltered internet access
Date: 2021oct9
Updated: 2023mar29
Keywords: captive portal
Q. Detect unfiltered internet access
A. There are a few company webpages for exactly this.
1. Windows >= 10 gets
http://www.msftconnecttest.com/connecttest.txt
Should return only "<pre>Microsoft Connect Test</pre>"
Content-Type: text/plain
(But you can use it in your program)
2. Windows < 10 gets
http://www.msftncsi.com/ncsi.txt
Should return only "Microsoft NCSI"
Content-Type: text/plain
NCSI stands for Network Connectivity Status Indicator
(But you can use it in your program)
3. Get http://detectportal.firefox.com
Should return only "success"
Content-Type: application/octet-stream
4. Get http://captive.apple.com
Should return "...<BODY>Success</BODY>..." in some HTML
Content-Type: text/html