Quad9 is a free security solution that uses DNS to protect your system against the most common cyber threats. It improves your system's performance, plus, it preserves and protects your privacy. It's like an immunization for your computer.  Quad9 routes your DNS queries through a secure network of servers around the globe. The system uses threat intelligence from more than a dozen of the industry's leading cyber security companies to give a real-time perspective on what websites are safe and what sites are known to include malware or other threats. If the system detects that the site you want to reach is known to be infected, you'll automatically be blocked from entry - keeping your data and computer safe.