What is Tor?
The Onion Router—a free network that routes your traffic through multiple layers of encrypted relays. No single relay knows both your identity and your destination. Tor enables anonymous browsing, access to .onion sites, and censorship circumvention.
Also known as: Tor Network, Tor Browser, The Onion Router
Tor is the gold standard for anonymous internet access. Used by journalists, activists, whistleblowers, and ordinary people who value privacy.
How Tor Works
- Tor Browser (or Tor client) connects to the Tor network
- Your traffic is encrypted and sent through three relays (guard, middle, exit)
- Each relay only knows the previous and next hop—never the full path
- Exit relay sends your traffic to the destination (sees your destination, not your identity)
- Guard relay sees your IP, but not where you're going (only knows you're using Tor)
No single relay has both your identity and your destination. That's the "onion" — layers of encryption, each peeled by one relay.
Tor vs. VPN
- VPN: One hop. VPN provider sees everything—your IP, your destination, your traffic (if unencrypted). Trust required.
- Tor: Three hops. No single party has full picture. Trust distributed across relay operators.
- Tor over VPN: VPN sees you're using Tor. Adds one layer of separation from your ISP.
- VPN over Tor: Complex. Generally not recommended for most users.
What Tor Protects
- Your identity from the destination (you appear as exit relay's IP)
- Your destination from your ISP (they see Tor traffic, not where you're going)
- Your traffic from observers (encrypted until exit relay)
What Tor Doesn't Protect
- Exit relay sees your traffic to non-HTTPS sites (can modify, log)
- Timing and volume analysis can sometimes correlate traffic
- Behavioral leaks—logging in, cookies, identifying yourself
- Tor Browser fingerprint—still unique enough to track across sessions
Use Cases
- Censorship circumvention: Access blocked sites
- Anonymous browsing: Research, activism, privacy
- .onion services: Hidden services that don't need to reveal their location
- Whistleblowing: SecureDrop and similar use Tor
Related Terms
Anonymity
The state of being unidentifiable or untraceable. In privacy contexts, anonymity means your actions cannot be linked back to your real identity—no one can connect your online activity to who you are.
Onion Routing
A technique for anonymous communication over a computer network where messages are encapsulated in layers of encryption, analogous to layers of an onion. Each relay decrypts one layer to reveal the next destination, but no single relay knows both the origin and final destination.
Virtual Private Network
A technology that creates a secure, encrypted connection over a less secure network, such as the public internet. VPNs mask your IP address, encrypt your internet traffic, and can make it appear as though you're browsing from a different location.