A website may sit on a blank screen for several seconds, then suddenly load at normal speed. Your internet connection looks fine, downloads are fast and videos play without buffering. Still, opening a new website feels slow. That delay often points to a slow DNS lookup.

DNS problems can come from your device, router, browser, VPN, ISP or the website itself. In this blog post, you’ll learn how to confirm a slow DNS lookup, find what is causing it and fix the problem without changing settings you don’t need to touch.

What Does Slow DNS Lookup Mean?

What Does Slow DNS Lookup Mean?

DNS translates a domain name such as example.com into the IP address used by your device. Your computer sends that request to a DNS resolver, which returns the address needed to reach the website.

A slow DNS lookup means this answer takes longer than it should. It mainly delays the start of the connection. If the page starts quickly but images and videos remain slow, the problem is more likely related to bandwidth, Wi-Fi, the website or its content delivery network.

Confirm That DNS Is Actually Slow

Before changing anything, check where the delay happens. DNS may not be the real problem. Weak Wi-Fi, packet loss and an overloaded website can create similar symptoms.

Symptom Likely Problem Area
Long pause before a website begins loading DNS resolution
Page starts quickly but images load slowly Bandwidth, server or CDN
Every app and website feels slow Wi-Fi, router or ISP
Only one domain has a delay That website’s DNS or server
The problem disappears on mobile data Home router, ISP DNS or local network

Ping results alone don’t show DNS lookup speed. Ping can help confirm network latency or packet loss, but you need a DNS query to measure name resolution.

Test DNS on Windows

Open PowerShell and run:

Measure-Command { Resolve-DnsName example.com }

Look at the TotalMilliseconds result. Run it a few times because the first request may be slower than later cached requests.

You can also check which DNS server answers through Command Prompt:

nslookup example.com

The result should show the resolver’s name or address followed by the answer for the domain.

Test DNS on macOS or Linux

Open Terminal and run:

dig example.com

Near the bottom, look for Query time. Repeat the test several times. A later request may be much faster because the resolver has cached the answer.

To test a particular DNS provider, use:

dig @8.8.8.8 example.com

Replace 8.8.8.8 with another resolver address when comparing results. Use the same domain for each test so the comparison stays useful.

Why Does Slow DNS Lookup Happen?

The delay can happen between your device and its DNS resolver. It can also happen when that resolver contacts the authoritative nameservers responsible for a domain.

Common causes include:

  • An overloaded or distant DNS resolver
  • Old or damaged entries in the local DNS cache
  • A router handling DNS forwarding poorly
  • Weak Wi-Fi or packet loss
  • Slow ISP DNS servers or poor routing
  • A VPN or proxy sending queries through a distant location
  • Antivirus, firewall or parental-control filtering
  • Incorrect Secure DNS or DNS over HTTPS settings
  • Broken or incomplete IPv6 connectivity
  • Slow authoritative nameservers for one website
  • DNSSEC or domain delegation problems
  • Malware that changed the device’s DNS settings

The pattern gives you a useful clue. If every device on one Wi-Fi network is affected, check the router or ISP. If only one computer is slow, focus on that device. When only one website has the problem, its DNS or hosting setup may be responsible.

How to Fix Slow DNS Lookup

Start with the basic fixes and test the same domain again. Don’t apply all changes at once. If you change everything together, you won’t know what actually solved the problem.

1. Restart the Browser, Device and Router

Close the browser completely, reopen it and test a few websites. If the delay remains, restart the device. This clears temporary processes and network states that may be slowing requests.

When several devices are affected, restart the router too. Disconnect its power, wait about 30 seconds and reconnect it. Give the router a few minutes to restore the internet connection. This can clear a stuck DNS forwarder or temporary router problem, though it won’t repair a bad DNS provider.

2. Flush the Local DNS Cache

Your operating system saves DNS answers so it doesn’t have to request them repeatedly. That normally makes browsing faster. A stale or damaged cache entry can sometimes cause delays, incorrect answers or repeated failures.

Flush the Local DNS Cache

On Windows, open Command Prompt as administrator and run:

ipconfig /flushdns

You should see a message confirming that the DNS Resolver Cache was cleared.

On macOS, open Terminal and run:

sudo dscacheutil -flushcache
sudo killall -HUP mDNSResponder

Enter your Mac password when requested. Terminal may not display a success message.

Many Linux systems using systemd-resolved support:

sudo resolvectl flush-caches

Linux DNS handling differs between distributions. If that command isn’t available, check which resolver service your system uses before trying another command.

The first lookup after flushing may be slower because the answer is no longer cached. Test the same domain more than once before judging the result.

3. Compare Your Current DNS Resolver With Another One

Changing DNS without testing can replace one slow provider with another. First, compare your current resolver against a trusted public resolver.

On Windows, find the current server with:

nslookup example.com

Then test Google Public DNS:

nslookup example.com 8.8.8.8

Test Cloudflare in the same way:

nslookup example.com 1.1.1.1

For clearer timing on macOS or Linux, run:

dig example.com
dig @8.8.8.8 example.com
dig @1.1.1.1 example.com

Run every test several times. DNS caching can make the second or third query much faster. Network distance also matters, so the fastest resolver for another person may not be the fastest one for you.

4. Change to a Faster Trusted DNS Server

If your current resolver is consistently slow or often times out, replace it with a tested alternative. Save the existing DNS addresses first so you can restore them later.

Common public DNS options include:

Provider Primary IPv4 Secondary IPv4
Google Public DNS 8.8.8.8 8.8.4.4
Cloudflare DNS 1.1.1.1 1.0.0.1

On Windows 11:

  1. Open Settings.
  2. Select Network & internet.
  3. Open Wi-Fi or Ethernet, depending on your connection.
  4. Find DNS server assignment and select Edit.
  5. Change the setting from Automatic to Manual.
  6. Turn on IPv4 and enter the preferred and alternate addresses.
  7. Save the change, reconnect and test again.

Windows menus can differ slightly between versions. On Windows 10, DNS settings may be found through the adapter properties in Control Panel.

A public DNS service may improve resolution, but it isn’t guaranteed. Your ISP resolver could be faster in your location. Test real results instead of selecting a provider only because it is popular.

5. Check Your VPN, Proxy and Security Software

VPNs often send DNS requests through the VPN provider to prevent DNS leaks. If the chosen VPN server is far away or overloaded, every lookup can take longer. A proxy may create a similar delay.

Temporarily disconnect the VPN or proxy and test again. Also check antivirus web protection, parental controls, ad blockers and security filters that inspect DNS traffic. If the delay disappears, update the affected software or change its DNS and server settings.

Turn security tools back on after the test. Don’t leave your firewall or antivirus disabled as a permanent solution. On a work or school device, ask the network administrator before changing managed settings.

6. Review Secure DNS or DNS Over HTTPS

Review Secure DNS or DNS Over HTTPS

Modern browsers can use DNS over HTTPS, often called Secure DNS. It encrypts DNS requests between the browser and the resolver. This may improve privacy and sometimes performance, but poor routing or a blocked provider can make it slower.

In Chrome:

  1. Open Settings.
  2. Select Privacy and security.
  3. Open Security.
  4. Find Use secure DNS.
  5. Check the selected provider or switch to the current service provider for testing.

In Firefox:

  1. Open Settings.
  2. Select Privacy & Security.
  3. Scroll to DNS over HTTPS.
  4. Review the current protection level and provider.
  5. Try another trusted provider or temporarily use the system resolver for comparison.

If changing this setting fixes the delay, the original encrypted DNS route may have been slow or blocked. You don’t have to leave Secure DNS disabled. Try another provider first, since turning it off also changes the privacy of your DNS traffic.

7. Check the Router’s DNS and Firmware Settings

When every phone and computer on the same network has slow lookups, the router deserves attention. Some routers receive DNS addresses from the ISP and forward all device queries through their own internal service. Older firmware or a busy router can slow that process.

Sign in to the router’s admin page and check the following:

  • Find the internet, WAN, LAN or DHCP section.
  • Note which DNS servers the router currently provides.
  • Check for an available firmware update.
  • Compare automatic ISP DNS with a trusted public resolver.
  • Save the original values before making changes.

Router menus vary a lot. Don’t change unfamiliar WAN, VLAN or authentication settings. One wrong value can disconnect the entire network.

If devices become faster when DNS is set directly on them, but remain slow through the router, its DNS forwarding may be the issue. Updating the firmware or setting trusted DNS addresses through DHCP may help.

8. Test IPv6 and IPv4 Separately

A partially working IPv6 connection can create an odd delay. The device may try IPv6 first, wait for it to fail and then fall back to IPv4. DNS itself might be working, yet the complete connection still feels like a slow lookup.

Temporarily compare the connection with IPv6 disabled on one test device. If performance immediately improves, don’t assume that IPv6 should remain disabled forever. The real issue may be the router, ISP route or IPv6 DNS configuration.

Check whether the router has valid IPv6 internet access and whether it provides reachable IPv6 DNS servers. Your ISP may need to correct the connection if IPv6 is advertised but doesn’t work properly.

9. Reset Network Settings as a Later Step

Reset Network Settings as a Later Step

A network reset can repair damaged adapter or TCP/IP settings, but it changes more than a DNS flush. Use it after the easier fixes fail.

On Windows 11:

  1. Open Settings.
  2. Select Network & internet.
  3. Open Advanced network settings.
  4. Select Network reset.
  5. Review the warning and choose Reset now.

The computer will remove and reinstall its network adapters. You may need to enter Wi-Fi passwords again or restore VPN and custom DNS settings. Save anything important before continuing.

Windows 10 normally places Network reset under Settings > Network & Internet > Status.

10. Check the Website’s Authoritative DNS or Contact the ISP

If every domain is slow on one network, but the same device works normally on mobile data, contact the ISP. Share your DNS test results, the resolver addresses used and examples of timeouts. That gives support something useful to investigate.

When only one website is slow, the problem may belong to that domain. Changing your local resolver might help with a poor cached route, but it can’t repair broken authoritative nameservers.

Website owners should check:

  • Whether every authoritative nameserver responds
  • Whether DNS answers are consistent across nameservers
  • Domain delegation at the registrar
  • DNSSEC validation
  • Slow or unreachable nameservers
  • Unnecessarily low TTL values
  • Recent DNS or nameserver changes

If one authoritative server is failing, visitors may experience random delays depending on which server the resolver contacts.

How to Prevent Slow DNS Lookups

Once DNS is working properly, avoid changing providers every few days. A stable resolver that performs well from your location is better than constantly chasing small benchmark differences.

A few habits can prevent the problem from returning:

  • Keep the router firmware updated.
  • Use reliable primary and secondary DNS servers.
  • Remove old VPN, proxy and DNS-filtering software you no longer use.
  • Check browser Secure DNS after major browser updates.
  • Test a resolver several times before switching to it.
  • Restart the router when DNS forwarding becomes unstable.
  • Scan the device if DNS settings change without permission.
  • Keep network and VPN drivers updated.
  • Monitor authoritative DNS if you manage a website.
  • Avoid very low DNS TTL values unless they serve a real purpose.

If you run a business network, track DNS response time and failed queries. Repeated timeouts are much easier to solve when you know when they started and which resolver was involved.

Final Thoughts

To fix a slow DNS lookup, first make sure DNS is actually causing the delay. Start by restarting the device and router, then flush the cache and compare the current resolver with another trusted option. Move on to VPN, Secure DNS, router and IPv6 checks only if the basic fixes don’t help. If every domain is slow on one network, involve the ISP. When only one website is affected, its authoritative DNS may need attention. Is your DNS slow on every website, one website or only one device?