Don't Let DNS Leaks Slow You Down: 4 Steps to Boost Your Internet Speed

Your internet clearly isn’t disconnected, yet web pages load extremely slowly, videos keep buffering, and even using an IP tool to access overseas websites feels as slow as a turtle? This is very likely related to DNS leaks.

Simply put, DNS acts like the “translator” of the internet, converting domain names into IP addresses. If it gets leaked, your network requests may take a longer route or even be recorded by third parties. This not only affects your privacy, but can also directly cause slow internet speed.

Today, we’ll walk you through DNS leak detection, DNS leak testing methods, and practical solutions to fix slow internet issues—so you can quickly restore a smooth browsing experience.

1. What Exactly Is a DNS Leak?

DNS works like the internet’s “phone book,” translating the website addresses you enter into IP addresses. If a DNS leak occurs, your requests may be “monitored” or even hijacked by third parties (including your ISP).

For example, you may use an IP tool to hide your real IP address. But if a DNS leak happens, the website can still identify your request source through your real DNS path. This is like “taking two routes” at once—naturally resulting in slower speeds.

2. How to Check If You Have a DNS Leak?

1. Online DNS Leak Test Website

There are many free tools available both domestically and internationally. Simply open the webpage to see the results. A typical test will display your DNS server address. If it doesn’t match your IP tool or your manually configured DNS, then a DNS leak has occurred.

2. Command-Line Check

If you’re familiar with CMD or Terminal, you can use the nslookup or dig commands to check where your DNS requests are going. If the displayed DNS server is not what you expect, it indicates a leak.

3. Browser Fingerprint Detection

Sometimes DNS leaks are also linked to browser information. Through browser fingerprint detection, you can see what information websites can collect from you. For example, you can use the ToDetect Fingerprint Checker to examine your browser fingerprint data. If you notice abnormalities, it may indicate a DNS leak or other network configuration exposure.

3. Signs That a DNS Leak Is Slowing Your Internet

•  Web pages load slowly, especially overseas websites

•  High latency and unstable download speeds when using IP tools

•  Some apps show “Connection Timeout” or “Network Error”

•  Frequent redirects to ISP ad pages or hijacked websites

If you’re experiencing these issues, a DNS leak could be the culprit.

4. DNS Leak Detection & Fix (Detailed Guide)

Method 1: Online DNS Leak Test

Open your browser and visit an online DNS testing website, or search for “DNS Leak Test.”

Steps:

•  After entering the site, click Standard Test or Extended Test

•  Wait a few seconds while the site displays your current DNS server

•  If the displayed DNS does not match your IP tool or local custom DNS, then a leak exists

Method 2: Command-Line Check

•  Windows: Open CMD and type nslookup www.google.com

•  macOS/Linux: Open Terminal and type dig www.google.com

Check whether the returned Server matches your expected DNS. If it shows your ISP’s DNS, then a leak is confirmed.

1. Switch to a Secure DNS

If a DNS leak is confirmed, the next step is switching to a secure DNS provider. Common public DNS options:

•  Google DNS: 8.8.8.8 / 8.8.4.4

•  Cloudflare: 1.1.1.1 / 1.0.0.1

•  OpenDNS: 208.67.222.222 / 208.67.220.220

Steps (Windows example):

•  Open Control Panel → Network and Sharing Center → Change adapter settings

•  Right-click your current network → Properties → Double-click Internet Protocol Version 4 (TCP/IPv4)

•  Select Use the following DNS server addresses and enter the DNS above

•  Click OK and restart your browser or network connection

•  Run another DNS leak test to confirm it’s fixed

On macOS or mobile devices, you can similarly change DNS under Network Settings → Advanced → DNS.

2. Check Your IP Tool Settings

Many IP tools do not enforce their own DNS by default. Without proper configuration, leaks can occur easily.

Recommendations:

•  Open your IP tool client settings

•  Find DNS/Network Leak Protection or DNS Leak Protection

•  Enable this feature to ensure all DNS requests go through the IP tool tunnel

•  Run another DNS leak test to confirm the issue is resolved

3. Use Browser Fingerprint Detection as Assistance

Although DNS leaks are mainly a network-layer issue, browser information can also reveal your location and network status.

Steps:

•  Open the ToDetect Fingerprint Checker

•  Click Start Detection → View browser, OS, IP address, and DNS information

•  If the information differs from what you expect, your DNS or browser data may be exposed

You can also enable browser anti-tracking extensions or use private browsing mode to reduce fingerprint tracking risks.

4. Clear DNS Cache and Browser Cache

Even after switching DNS servers, old cached records in your system or browser may still affect speed.

How to do it:

•  Windows: In CMD, enter ipconfig /flushdns

•  macOS: In Terminal, enter sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder

•  Browser: Clear cache, cookies, and DNS cache

After completing these steps, your internet performance should noticeably improve.

5. DNS Leaks Causing Slow Internet – Prevention Tips

•  Use a reliable VPN and enable DNS leak protection

•  Avoid unsecured public Wi-Fi networks

•  Regularly check your DNS and browser fingerprint status

•  Install anti-tracking extensions or use a privacy-focused browser to reduce leak risks

In Conclusion

DNS leaks not only affect privacy but can also make your internet unbearably slow. The good news is that this issue can be fully resolved through proper testing and configuration.

By performing DNS leak detection and DNS leak testing, combined with ToDetect Browser Fingerprint Detection, you can quickly identify problems and restore a normal browsing experience.

The next time you experience slow loading pages or high latency, don’t rush to change your internet provider. Check for DNS leaks first—just a few simple steps could bring your browsing experience back to normal.