DNS-over-TLS (DoT) is a security protocol that encrypts Domain Name System (DNS) queries using Transport Layer Security (TLS). By wrapping DNS traffic in a layer of encryption, DoT prevents third parties—like ISPs, attackers, or network snoops—from seeing or tampering with your DNS activity.
🛡️ Why Use DNS-over-TLS?
Traditional DNS queries are sent in plaintext, making it easy for anyone on the network path to observe or modify them. This can lead to:
- Privacy risks (your ISP seeing every site you visit),
- Security risks (attackers spoofing DNS responses),
- Censorship (DNS requests being blocked or redirected).
DoT mitigates these risks by:
- Encrypting the full DNS query and response,
- Authenticating the DNS resolver, ensuring the response hasn’t been tampered with,
- Maintaining compatibility with existing DNS infrastructure (unlike DoH which uses port 443).
🔍 How Does DoT Work?
- A DNS client (your device) establishes a TLS-encrypted TCP connection to a DoT-enabled DNS resolver (typically on port 853).
- All DNS queries and responses are exchanged over this encrypted channel.
- The resolver processes your request and responds securely.
🆚 DNS-over-TLS vs DNS-over-HTTPS
| Feature | DoT | DoH |
|---|---|---|
| Protocol | TLS | HTTPS (TLS over HTTP/2) |
| Default Port | 853 | 443 |
| Visibility to Firewalls | Easier to identify/block | Harder to detect (uses port 443) |
| Use Case | System-level DNS encryption | Application/browser-level DNS encryption |
DoT is often favored by network administrators due to its transparency and easier filtering, while DoH is preferred for bypassing censorship and working in browser apps.
🌐 CleanBrowsing and DoT
CleanBrowsing supports DNS-over-TLS across all its free and paid plans. Each user is assigned unique DoT endpoints that can be used to:
- Secure home networks,
- Lock down school or enterprise environments,
- Ensure kids’ safety with encrypted filtering.
You can find your personalized DoT configuration by logging into your CleanBrowsing dashboard.