Web content filtering based on keyword

[alanl96]

Hi everyone. I want to make an OPN sense router. I would like to know if I can filter content based on keyword. Foster kids can easily bypass my circle device without a VPN and get adult content through Wish and Amazon searches. I want to filter content on all websites. Thanks for your help!

[EdwinKM]

That is difficult. Most website are encrypted (HTTPS). This is invisible to the router. To inspect traffic you need to decrypt it, meaning MitM capturing. This also means that users are getting untrusted ssl warnings and you have to install self singned certificates on all clients (browsers).
I is just not worth is....

Blocking DNS resolving using DNSBL is the most feasible way to try to block stuff. But this works on domain names. Thus you block "Amazon" completely in that instance.

That said. Why try to block if someone is really looking specifically for adult content?

[Danrow]

If you suspect that you have a content filter, you can compare what you expect to see when visiting a web site to what you actually see.