What Is Private DNS? How Does It Work?

September 11, 2026 By Nancy William No Comments 8 minutes

Some devices come with built-in Private DNS, found within settings. If you’re not sure what that is or what it’s for, this guide is for you. We’ve highlighted explanations on the query “What is Private DNS?” to help you figure out what it is and how to stop your internet provider from seeing every site you visit. 

We’ve covered what it is, how it works, its benefits, risks, and how it relates to VPNs like FastestVPN.

What is Private DNS?

Private DNS is a security feature that encrypts your DNS (Domain Name System) queries. To better understand why this matters, let’s first break down what DNS is.

What is DNS?

DNS can simply be described as the “phonebook” of the internet. For instance, when you type a website name into your browser, like fastestvpn.com, your device needs the corresponding numerical IP address to connect to it.

Upon this, a DNS server then translates that domain name into an IP address, which lets your browser load the site.

However, what is the common problem with DNS requests? Unfortunately, most DNS queries, by default, are sent as unencrypted plaintext. This means your ISP, anyone on the same public Wi-Fi network, or a hacker with the right tools can see what websites you’re visiting.

How Does Private DNS Work?

Private DNS encrypts your DNS queries with secure protocols. Instead of sending requests in plain text, it wraps them in an encrypted tunnel. This makes them unreadable to anyone monitoring your network traffic. 

In layman’s terms, it’s like sealing a postcard in an envelope. The address is still visible, but no one can read the message inside.

Private DNS vs Public DNS

Here are the differences:

Public DNS (Default)

A public DNS is when your queries are sent in plain text. Your ISP or network administrator can see every domain you look up. Even though it’s convenient, it exposes your browsing activities.

Private DNS

It’s is when your queries are encrypted. Your ISP can see that you’re making DNS requests, but cannot read the particular domain names you visit. This significantly improves your online privacy.

Is Private DNS Safe?

Yes, private DNS is generally considered safe, but not entirely. However, even though it’s not the complete privacy solution, it does offer several important security benefits. It’s a specific tool for protecting one part of your internet traffic. Take a look below at a few privacy benefits of Private DNS:

1. Enhanced Online Privacy

By encrypting your DNS queries, private DNS makes it much harder for third parties to see the domains your device is looking up. Regardless of whether you’re worried about being tracked by your ISP, an advertiser, or a malicious actor over public Wi-Fi, private DNS adds an important layer of protection to your online activity.

2. DNS Attack Prevention

Private DNS helps protect against several types of DNS-based cyber threats. These include:

• DNS spoofing – Attackers intercept DNS queries and redirect you to fake websites.
• DNS cache poisoning – Malicious data is inserted into a DNS resolver’s cache. This then leads users to fraudulent sites.
• DNS hijacking – Attackers redirect DNS queries to their own servers.

Encryption prevents attackers from intercepting and altering DNS queries and responses. This reduces your exposure to phishing campaigns and malware.

3. Reduced Third-Party Tracking

Some private DNS providers offer features that block known tracking domains and unwanted ads at the DNS level. This prevents your device from connecting to analytics services and advertisers, adding an extra layer of privacy.

Private DNS Security Risks to Consider

As mentioned, even though private DNS is a powerful tool, it comes with a catch: you’re shifting your trust from your ISP to your chosen DNS provider. Your encrypted queries are still fully visible to the resolver handling them. 

This is considered a huge risk. It’s why it’s important to choose a DNS provider with a strong privacy policy and a no-logs policy. Some providers may log your queries or monetize the data.

Other Limitations

Other than that, here’re a few more limitations:

• Does not hide your IP address – Always be warned that private DNS doesn’t hide your IP. Your ISP still sees the IP addresses of the servers you connect to. For major websites, these IP addresses are often enough to identify the service you’re using.
• SNI exposure – During the initial HTTPS handshake, your device often sends the hostname in plain text through SNI (Server Name Indication). This means even with encrypted DNS, the very next packet your computer sends can contain the domain name in readable form.
• DNS leaks – Some apps use their own hardcoded DNS resolvers and ignore your system settings. So, if you’re using a VPN, a misconfiguration can cause DNS queries to bypass the VPN tunnel. You can always learn to fix DNS leaks.

How Private DNS Benefits You (Different Use Cases)

Here’s how:

On Mobile Devices

Mobile users benefit significantly from private DNS. Whether you’re on cellular data or connecting to different public Wi-Fi networks, it ensures your DNS queries remain encrypted. This is especially important on unsecured networks like coffee shops, airports, and hotels.

Smart Home Devices

Most IoT devices rely on DNS to communicate with their servers. Private DNS helps shield your cameras, speakers, and thermostats from DNS-based attacks and tracking.

For Reducing Ads and Tracking

Companies often use DNS requests to build profiles based on your browsing behavior. Private DNS encryption prevents data collectors from accessing sensitive data. This, in turn, results in fewer targeted ads and less data profiling.

To Bypass Censorship

In some countries, governments block specific websites by interfering with DNS queries. This is where an international private DNS resolver comes in handy. It helps bypass these simple but effective censorship blocks. However, if you really want to remain private while bypassing censorship, you need a VPN.

How Does Private DNS Help VPNs?

As mentioned, Private DNS and VPNs are different technologies, but they do complement each other. Here’s how: 

The VPN Advantage

A VPN is far more comprehensive and advanced compared to private DNS. It helps encrypt all of your internet traffic, not just DNS queries, and routes it through a secure tunnel to a VPN server. 

This masks your IP address, hides visited website IPs, and protects all your data from network trackers.

VPNs with Built-in Private DNS

Some VPNs, like FastestVPN, manage DNS internally. This means they handle DNS queries within the encrypted VPN tunnel, preventing third parties from seeing them. It’s often the preferred approach for maximum privacy.

Private DNS Can Interfere with VPNs

On some devices, setting a separate private DNS resolver can override the VPN’s own DNS settings. This messes with how your internet works. Depending on the platform, the DNS queries may leave the VPN tunnel. For the best results, it’s usually preferable to let the VPN manage DNS unless you have a specific reason to configure it manually.

Private DNS Protocols – DoT vs DoH

Private DNS uses specific encryption protocols. The two most common are DNS over TLS (DoT) and DNS over HTTPS (DoH). Even though both encrypt DNS queries, they work differently. Here’s how: 

DNS over TLS (DoT)

• Port – Uses a dedicated port, 853.
• Operation – Adds TLS encryption on top of the UDP used for DNS queries. It creates an encrypted, persistent channel.
• Coverage – It is system-wide. Once configured, it encrypts DNS for any application on the operating system.
• Packet size – It’s lighter than DoH because it operates at a lower level.
• Network visibility – Since it uses a dedicated port, network administrators can easily see and potentially block DoT traffic.

DNS over HTTPS (DoH)

• Port – Uses port 443, the same as standard HTTPS web traffic.
• Operation – Encrypts DNS queries inside regular HTTPS traffic. Since it looks like normal web traffic, it is harder to distinguish from other HTTPS connections.
• Coverage – Often configured on a per-application basis, for instance, in browsers like Firefox.
• Packet size – Larger than DoT because it operates at the Application Layer.
• Privacy – Provides more privacy because DNS queries are hidden within the larger flow of HTTPS traffic.

To Conclude

As we wrap up this guide on “what is Private DNS,” we can round off by stating that it’s a valuable tool for improving your online privacy. 

It encrypts your DNS queries, making it harder for your ISP, hackers on public Wi-Fi, and advertisers to see the websites you visit.

However, don’t think of it as 100% safe, as it’s not the best or most complete privacy solution. It does not hide your IP address, and you need to choose your DNS provider carefully.

Even though it adds a layer of protection, it’s not as good as a VPN. FastestVPN offers a more comprehensive solution by encrypting all of your internet traffic while masking your IP.