Explore how .onion domains differ from normal web addresses, why they exist, and discover other addressing systems used in alternative anonymity networks such as I2P, Freenet, and ZeroNet.
What Is an `.onion` Address?
An .onion address is a special domain suffix used exclusively on the Tor network.
You cannot access it using normal browsers or DNS lookups — it works only through the Tor Browser or other Tor-connected software.
Example
http://facebookcorewwwi.onion/
http://protonirockerxow.onion/ http://duckduckgogg42xjoc72x3sjasowoarfbgcmvfimaftt6twagswzczad.onion/Each .onion address corresponds to a hidden service (now called an “Onion Service”).
Unlike standard websites where the domain name is registered via a centralized authority (ICANN), .onion addresses are self-generated cryptographically from a public key.
That means the long, random-looking string in the address actually encodes part of the site’s cryptographic identity — it’s self-authenticating, which makes phishing harder and anonymity stronger.
How `.onion` Works
When you visit an .onion site through Tor:
- Your Tor Browser connects through multiple relays (nodes) — at least three — forming a private encrypted route.
- The
.onionsite itself is also hidden behind the Tor network — its server IP address is never exposed.
- Both sides meet inside Tor, keeping both the user and the server anonymous.
This system provides end-to-end encryption and location anonymity, making it useful for:
- Journalists protecting sources.
- Whistleblowers sharing sensitive documents.
- Users in censored regions accessing blocked content.
- Organizations hosting privacy-preserving portals.
Examples of Legitimate `.onion` Websites
| Service | Purpose | Onion Address |
|---|---|---|
| Private social networking access in censored countries | facebookcorewwwi.onion | |
| ProtonMail | Anonymous encrypted email | protonirockerxow.onion |
| The New York Times | Secure whistleblower portal | nytimes3xbfgragh.onion |
| DuckDuckGo | Private search engine | duckduckgogg42xjoc72x3sjasowoarfbgcmvfimaftt6twagswzczad.onion |
These examples are **official** and maintained by the organizations themselves for privacy and anti-censorship purposes.
Other Dark Web Extensions and Networks
While .onion belongs to Tor, other anonymity networks use their own internal addressing systems — each with its own design goals and structure.
| Network | Example Address | Extension/Format | Description |
|---|---|---|---|
| Tor | abc123xyz.onion | .onion | Most popular network for anonymous browsing and hosting. |
| I2P (Invisible Internet Project) | example.i2p | .i2p | Uses "eepsites" for internal anonymous services and messaging. |
| Freenet | freenet://USK@... | none (key-based) | Fully decentralized content store with data persistence. |
| ZeroNet | 1HeLLo4uzjaLetFx6NH3PMwFP3qbRbTf3D | Bitcoin-style address | Combines BitTorrent & Bitcoin crypto for distributed sites. |
| Lokinet | http://example.loki/ | .loki | Based on the Oxen blockchain, focuses on secure routing and messaging. |
| GNUnet | (no TLD, peer IDs only) | — | Academic network for decentralized, censorship-resistant communication. |
Each of these operates outside the regular DNS system and requires its own client or browser configuration to access.
Why So Many?
Each network reflects a different philosophy of privacy:
- Tor emphasizes global anonymity and simple access.
- I2P focuses on internal services and peer-to-peer connections.
- Freenet aims for censorship resistance through distributed storage.
- ZeroNet experiments with blockchain-style identities.
- Lokinet explores mix networks over blockchain infrastructure.
Together, they form an ecosystem of technologies all designed to reduce reliance on centralized control and preserve privacy — though not all are equally secure, active, or widely used.
Risks and Ethical Considerations
While these technologies have legitimate uses, not all content or activity within them is lawful.
Illegal marketplaces, data leaks, and scams often exist alongside privacy tools and research forums.
Use anonymity networks responsibly:
- Do not download or interact with illegal content.
- Keep systems isolated and patched.
- Verify sources before trusting links or data.
- Always prioritize legality, ethics, and safety.
Answer the questions
What network uses `.onion` addresses?
Answer: Tor
What is the equivalent extension used by I2P?
Answer: .i2p
Which network uses Bitcoin-style addresses instead of domains?
Answer: ZeroNet
Closing Thoughts
.onion and other dark web extensions are gateways to privacy-preserving technologies, not inherently criminal tools.
They empower journalists, activists, researchers, and everyday users seeking security and freedom from surveillance — but must always be used responsibly and legally.
Understanding how these extensions work helps demystify the dark web, turning fear into knowledge and encouraging ethical exploration of internet privacy technologies.