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Feature overview
Charles
2026-10-09 10:33Many users only focus on whether their current IP address has changed when checking the network environment, but overlook the DNS query process.
The purpose of DNS Leak Test is to help users check which servers their current DNS queries actually pass through, and whether the region and carrier information of these DNS servers match the current network environment.
Simply put, DNS leak detection does not focus on "whether there is a DNS", but on: who ultimately processes your domain name resolution requests. Today we will teach you how to easily use a DNS leak detection tool.
1. What is a DNS Leak? First Understand the DNS Query Process
The main function of DNS (Domain Name System) is to convert website domain names into IP addresses that devices can recognize. During this process, DNS queries may pass through different types of resolution services:
• Default DNS provided by your ISP
• Public DNS manually configured by the user
• DNS configured by the enterprise or router
• Built-in secure DNS service in the browser
Under normal circumstances, DNS queries should run according to the user's current network configuration.
However, in some cases, even if the user has changed the DNS or enabled an encrypted DNS service, the actual query requests may still pass through the original DNS server.
Therefore, a DNS leak does not necessarily mean that there is a network failure. More accurately, it means that the DNS query path deviates from your settings.
2. Why Do You Need to Check for DNS Leaks?
Although a DNS query itself does not directly display the full content of your access, it may record which domain names you have requested. For example, when you visit a website, the DNS server usually needs to know the corresponding domain name request before returning the resolution result.
In the long run, DNS query records may reflect certain access habits and network behaviors. Parties that may access DNS query information include:
• Your current network ISP
• Public WiFi administrator
• DNS service provider
• Intermediate network nodes
In addition, abnormal DNS behavior may also affect network environment judgment. Therefore, when troubleshooting network issues, DNS usually needs to be checked together with the IP address, WebRTC detection, and browser environment.
3. How to Run a DNS Leak Test? Practical Operation Guide
| Detection Step | Operation Method | Information to Focus On | How to Judge |
|---|---|---|---|
| Open the Detection Tool | Go to the DNS Leak Test page and wait for the page to automatically load the detection results | Current public IP, DNS server list, DNS attribution information | Confirm that the detection page can normally read the current network environment |
| View Public IP | First record the public egress IP address displayed on the page | Country, region, and carrier information of the IP | Use it as a reference for subsequent judgment on whether the DNS location matches |
| Check DNS Servers | View the DNS server addresses in the detection results | DNS service provider, carrier, and location | Focus on confirming whether the DNS comes from the expected resolution service |
| Compare DNS and IP Locations | Compare the DNS attribution region with the location of the public IP | Whether the IP location and DNS node location are consistent | Different regions are not necessarily abnormal. You need to judge based on the DNS service provider situation |
| Check Changes in DNS Sources | Refresh or re-detect multiple times to observe changes in DNS results | Whether DNS from different regions or different carriers appears frequently | If DNS that does not match your settings appears for a long time, further troubleshooting is required |
| Retest After Changing Settings | Adjust the DNS, browser secure DNS, or network configuration and then run the detection again | Differences in DNS results before and after modification | Confirm whether the new DNS configuration has actually taken effect |
4. What to Do After Detecting a DNS Leak?
After finding abnormal DNS results, it is not recommended to immediately assume that the DNS configuration has failed. You can check according to common causes one by one.
First, you can check the system DNS configuration. After modifying the DNS address on some devices, the system cache or network configuration is not updated immediately, causing the detection to still read the old resolution path.
Second, check the secure DNS settings in your browser. Many browsers currently support the independent DNS over HTTPS (DoH) feature. The browser may prefer to use its own DNS settings instead of fully following the system configuration.
For example, if your computer system is set to a certain DNS, but the browser has enabled secure DNS, the actual queries may be processed by the DNS server specified by the browser.
In addition, IPv6 is also an easily overlooked item. In some network environments, IPv4 and IPv6 may use different DNS configurations. If you only modify the IPv4 DNS while IPv6 still uses the default settings, inconsistent detection results may appear.
Finally, you can clear the DNS cache, change the network environment, and re-run the detection. In actual troubleshooting, many DNS abnormalities are not caused by a single reason, but are the combined effect of system, browser, and network configurations.
5. Can DoH and DoT Solve DNS Leaks?
Currently, the common encrypted DNS methods include DoH (DNS over HTTPS) and DoT (DNS over TLS). Their main function is to add encryption protection to the DNS query process, reducing the risk of query content being directly viewed during transmission.
However, please note that encrypted DNS does not mean completely hiding all network information. DoH and DoT mainly protect the DNS query process. They will not change your public IP, nor will they affect other network features such as browser fingerprints and WebRTC information.
Therefore, if you want to perform a complete network environment detection, you usually need to pay attention to:
• IP address information
• DNS resolution status
• WebRTC status
• Browser environment parameters
• Time zone and language settings
DNS is only a small part of the entire network environment.
6. Common Questions About DNS Detection
If the direct connection status shows the ISP's DNS, is it definitely a leak?
No. If you have not modified the DNS settings, using the DNS provided by your ISP is a normal situation. To determine whether there is a leak, you need to combine it with your actual configuration to see if the DNS bypasses your expected settings.
Why do multiple DNS servers appear in the detection results?
This is quite common. Some DNS services use multiple resolution nodes, and the detection tool may display multiple server addresses. You need to make a comprehensive judgment based on the DNS attribution, region, and your network environment.
Why does it still show the original DNS after I modified it?
Common reasons include: the browser's secure DNS is still enabled; the system DNS cache has not been refreshed; IPv6 still uses the default DNS; the router configuration has not been synchronized. You can check them one by one and re-test.
What is the difference between a DNS leak and an IP leak?
The two focus on different information. A DNS leak mainly exposes the domain name query path, that is, "which websites you have queried". An IP leak mainly exposes the current network egress location, that is, "where you are accessing from".
7. What Other Network Information Should You Pay Attention to Besides DNS Detection?
Many people stop after finishing the DNS Leak Test, but judging the actual network environment is not just about DNS. For example:
• IP detection can check your current public IP, region, carrier, ASN, and risk information.
• WebRTC detection can check whether the browser has additional exposed network egresses.
• Browser detection can check whether environment parameters such as time zone, language, and User Agent are consistent.
• Only by combining these information can you more comprehensively judge whether the current network environment meets your expectations.
Especially after changing networks, modifying DNS configurations, switching devices, or adjusting browser settings, re-running a full set of detections makes it easier to find hidden problems.
Conclusion
DNS Leak Test is a simple method to check whether the DNS query path meets your expectations. When detecting, do not only look at a single result. Instead, you should make a comprehensive judgment by combining the source of the DNS server, attribution region, IP location, and current network configuration.
If you find abnormalities, you can troubleshoot them item by item from the system DNS, browser secure DNS, IPv6 configuration, and cache.
A DNS leak is not an unsolvable problem. The key is to find the actual query path through detection first, and then make adjustments according to the cause. For users who frequently change network environments, regularly checking the DNS status can help you detect abnormalities caused by configuration changes in time.
