You know a VPN hides your IP and encrypts traffic. But how does it actually work? Here's the technology behind VPNs — explained clearly.

The Core Concept: An Encrypted Tunnel

A VPN creates an encrypted tunnel between your device and a VPN server. All your traffic flows through this tunnel before reaching the internet. From the outside, it looks like traffic originating from the VPN server, not from you.

Step by Step: What Happens When You Connect

  1. Your device authenticates with the VPN server and establishes an encrypted session
  2. Your device receives a new virtual IP address from the VPN
  3. All outgoing traffic is encrypted and sent to the VPN server
  4. The VPN server decrypts it and forwards it to the destination
  5. The response returns to the VPN server, gets encrypted, and is sent back to you

Websites only see the VPN server's IP address — never yours.

Encryption: How Your Traffic Is Protected

Modern VPNs use AES-256 encryption — the same standard used by governments and financial institutions. Brute-forcing it with current hardware would take longer than the age of the universe.

VPNs also use asymmetric key exchange (Diffie-Hellman) to securely establish encryption keys at session start. Even if someone records your encrypted traffic today, they can't decrypt it later.

VPN Protocols

A protocol defines how the tunnel is created and maintained:

  • WireGuard: Modern, fast, minimal codebase (~4,000 lines). Now the default for most major VPN providers.
  • OpenVPN: Battle-tested, open source, highly configurable. Slightly slower than WireGuard.
  • IKEv2/IPSec: Fast reconnection, good for mobile. Built into most operating systems.
  • L2TP/IPSec: Outdated — avoid if possible.

What a VPN Hides (and Doesn't)

A VPN hides:

  • Your real IP address from websites
  • Your browsing activity from your ISP
  • Your traffic content on public Wi-Fi

A VPN doesn't hide:

  • Your activity from the VPN provider itself
  • Your identity if you're logged into accounts
  • Malware already on your device

Kill Switch

If your VPN connection drops, traffic could briefly go through your real IP. A kill switch blocks all traffic if the VPN disconnects — preventing accidental exposure.

DNS Leaks

Even with a VPN active, DNS queries might bypass the VPN tunnel and go to your ISP's DNS server — revealing which sites you visit. A properly configured VPN routes DNS through its own servers. Use our DNS lookup tool to inspect DNS records directly.

Conclusion

A VPN works by creating an encrypted tunnel between you and a server, routing all traffic through it. The core technologies — AES-256, modern protocols like WireGuard, and proper DNS handling — make it a reliable privacy tool. The protocol and logging policy matter as much as the encryption strength.