DNS

What is DNS?

DNS, or the Domain Name System, is like a phone book for the internet. When you type "google.com" into your browser, your computer doesn't actually know where Google lives. It asks a DNS server to look up the name and return the real address (an IP address like 142.250.80.46) so your computer can connect.

This lookup happens every time you visit a website, load an image from another server, or open an app that connects to the internet. Most of the time it takes just a few milliseconds and you never notice it. But when DNS is slow or broken, every website feels like it takes forever to load, even if your internet connection is fast.

Why it matters

Slow DNS is one of the most common causes of websites feeling sluggish. Because every new connection starts with a DNS lookup, a slow DNS server adds delay to everything you do online. If your DNS server takes 200ms per lookup, that delay stacks on top of the actual time it takes to load each page.

DNS problems can also make sites completely unreachable. If your DNS server goes down or can't find an address, your browser shows an error even though your internet connection is working fine. This is why "have you tried a different DNS server?" is one of the first things tech support suggests.

What you can do

• Switch to a faster DNS provider like Cloudflare (1.1.1.1), Google (8.8.8.8), or Quad9 (9.9.9.9). See our DNS Setup Guide for step-by-step instructions.
• If your DNS suddenly got slow, try restarting your router. Sometimes its internal DNS cache gets stale or overloaded.
• Use Network Weather to compare your current DNS performance against alternatives so you can pick the fastest option for your location.
• If websites fail to load but other internet services work, DNS is likely the culprit. Switching to a public DNS server is a quick fix.
• Consider setting your DNS at the router level so every device in your home benefits, not just one computer.
• Flush your local DNS cache if a specific website isn't loading. On macOS, open Terminal and run: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

What Network Weather shows you

Network Weather measures how long DNS lookups take and compares your DNS server's performance against popular alternatives like Cloudflare and Google.