Web content filtering is included in leading next generation firewalls, but is also available as standalone hardware or software solutions.
Generally, web content filtering works by identifying keywords and phrases, objects in images, and other strings of data consistent with undesirable content. The filter blocks access when this content is identified.
The best solutions also use DNS filtering, which is a method of filtering based on a website’s IP address. Every website has a unique IP address. The filter knows the IP addresses of risky and inappropriate websites, so it’s able to block those websites from being accessed on your network. This method also allows administrators to create a custom blocklist of websites that cannot be accessed, or whitelist websites that are mistakenly blocked.