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What Is a DNS Resolution Failure (and How to Fix It)

If you see an error like "Server not found," "This site can’t be reached," or "DNS_PROBE_FINISHED_NXDOMAIN," the problem isn't the website itself, but your computer's ability to *find* it. This is a DNS error.

What Is DNS?

Think of the **Domain Name System (DNS)** as the internet's phonebook. You type in a friendly website name (like google.com), and DNS translates that into a computer-friendly IP address. Your browser then connects to that IP address.

A "DNS resolution failure" means your computer asked the phonebook for the IP address, and the phonebook couldn't find a listing for that domain. The site might be "UP" (our tool would say so), but your computer can't find its address.

How to Fix DNS Errors (For Visitors)

1. Clear Your Browser Cache

Your browser might be holding on to an old, bad DNS record. Clearing your cache forces it to look for a fresh one.

2. Flush Your Local DNS Cache

Your operating system also keeps a DNS cache. Flushing it can solve the problem.

  • On Windows: Open Command Prompt and type ipconfig /flushdns and press Enter.
  • On Mac: Open Terminal and type sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder and press Enter.

3. Change Your DNS Resolvers

By default, you use your Internet Service Provider's (ISP) DNS servers. You can switch to free, fast, public DNS servers like Google's (8.8.8.8) or Cloudflare's (1.1.1.1).