What Is a VPN?
Understand how VPNs work, the encryption and tunneling protocols they use, common use cases, and their limitations.
How a VPN Works
A VPN (Virtual Private Network) creates an encrypted tunnel between your device and a remote server operated by the VPN provider. All your internet traffic is routed through this tunnel, which hides your real IP address and encrypts your data in transit.
Here is the process step by step:
- You connect to a VPN server (e.g., in another country).
- Your device and the VPN server perform a handshake and establish an encrypted tunnel.
- All your internet traffic is encrypted and sent through this tunnel to the VPN server.
- The VPN server decrypts your traffic and forwards it to the destination (e.g., a website).
- The website sees the VPN server's IP address, not yours.
- Responses travel back through the tunnel to your device.
What a VPN Hides: Your real IP address, your physical location (as inferred from IP), your browsing activity from your ISP, and unencrypted data from network eavesdroppers. It does not make you anonymous - the VPN provider can see your traffic.
VPN Protocols
VPN protocols determine how the encrypted tunnel is created and maintained. Each has different trade-offs in speed, security, and compatibility:
| Protocol | Speed | Security | Notes |
|---|---|---|---|
| WireGuard | Excellent | Strong | Modern, lightweight (~4,000 lines of code), fastest option. Becoming the new standard. |
| OpenVPN | Good | Very strong | Open-source, battle-tested, runs on TCP or UDP. Most widely supported. |
| IKEv2/IPSec | Very good | Strong | Excellent for mobile - reconnects quickly when switching networks. |
| L2TP/IPSec | Moderate | Moderate | Older protocol, double encapsulation adds overhead. Largely superseded. |
| PPTP | Fast | Weak | Obsolete - known vulnerabilities. Should not be used for security. |
Common VPN Use Cases
People use VPNs for a variety of reasons:
- Privacy from ISPs: Prevents your ISP from monitoring and logging your browsing activity.
- Public Wi-Fi security: Encrypts your connection on untrusted networks (coffee shops, airports, hotels) to prevent eavesdropping.
- Accessing geo-restricted content: Connect to a server in another country to access region-locked streaming services or websites.
- Bypassing censorship: In countries with internet restrictions, VPNs can provide access to blocked websites and services.
- Remote work: Businesses use VPNs to allow employees to securely access internal resources from outside the office.
- Avoiding IP-based tracking: Changing your visible IP makes it harder for advertisers to track you across websites.
VPN Limitations
VPNs are powerful tools, but they are not a silver bullet for online privacy:
- Not true anonymity: Your VPN provider can see your traffic. If they keep logs, that data could be subpoenaed or breached.
- DNS leaks: If configured improperly, your DNS queries may bypass the VPN tunnel, revealing the websites you visit. Use our IP Leak Test to check.
- WebRTC leaks: Browsers can reveal your real IP through WebRTC even while connected to a VPN.
- Speed reduction: Encryption and routing through a remote server adds latency and reduces throughput, typically by 10–30%.
- VPN blocking: Some services (streaming platforms, banks) actively detect and block VPN IP addresses.
- Doesn't protect against malware: A VPN encrypts your connection but does not scan for viruses or block phishing sites (unless the provider offers additional features).
Choosing a VPN
When selecting a VPN service, consider these factors:
- No-logs policy: Choose a provider that has been independently audited and does not store activity logs.
- Jurisdiction: The VPN provider's legal jurisdiction affects what data they may be compelled to hand over.
- Protocol support: Look for WireGuard or OpenVPN support for the best balance of speed and security.
- Kill switch: A kill switch blocks all internet traffic if the VPN connection drops, preventing accidental IP exposure.
- Server locations: More server locations give you more options for geo-unblocking and better performance.
Pro Tip: After connecting to a VPN, always verify that it is working correctly by running an IP leak test. Check that your IP, DNS, and WebRTC are all showing the VPN server's information, not your real details.
IP Leak Test
Use our free online tool - no signup required