DNS (Domain Name System)

What It Means

The Domain Name System (DNS) is the internet's address book: it translates human-readable domain names (like google.com or netflix.com) into the IP addresses that routers and servers actually use (like 142.250.80.46). Every web page load, API call, email delivery, and app connection begins with one or more DNS lookups. By default, your device uses your ISP's DNS resolver (set automatically via DHCP), which is typically adequate but often slower than commercial alternatives and may log your browsing activity. Alternative DNS providers and their typical response times: Cloudflare (1.1.1.1, 10 to 15 ms average), Google Public DNS (8.8.8.8, 15 to 25 ms average), Quad9 (9.9.9.9, 15 to 30 ms average with built-in phishing and malware blocking), OpenDNS (208.67.222.222, 20 to 40 ms average with family-friendly filtering), and NextDNS (customizable filtering, 15 to 30 ms average). Switching from a slow ISP DNS to a fast third-party DNS can reduce initial page load times by 20 to 100 ms per site, noticeable on image-heavy pages that issue dozens of DNS lookups. DNS does not affect bulk download speed or speed test results, the initial DNS lookup happens once and subsequent traffic is pure IP-level transfer. Modern browsers support DNS over HTTPS (DoH) and DNS over TLS (DoT), which encrypt DNS queries so neither the ISP nor on-path observers can see what sites you look up. Chrome, Firefox, and Safari all enable DoH by default when the configured resolver supports it.

Frequently Asked Questions