Addresses made of keys
.onion was formally reserved in 2015 by RFC 7686 so that it would never be delegated in the public DNS. Instead of a registry, each onion service's address is computed from its public key — which is why addresses look like long random strings. Only the Tor network knows how to route to them.
Many mainstream organizations run onion services so readers can reach them privately, including news outlets and social networks. If you use them, get the address from the organization's official site; look-alike onion addresses are a common phishing trick.
Good for
- Privacy-preserving access to sites through the Tor network
Watch out for
- Look-alike phishing addresses are common — verify an onion address from a trusted source
.onion by the numbers
.onion is a special-use name, not a regular top-level domain. Its purpose: used to access devices over the Tor network.
Used to access devices over the Tor network.
For further information, see The ".onion" Special-Use Domain Name (RFC 7686).
You can't register a name under .onion at any registrar, and it's not meant to resolve on the public internet. That's exactly why it's useful: software and people can rely on it never colliding with a real website.
.onion FAQ
Can I register a .onion domain?
No. A .onion address is derived from a service's cryptographic key by the Tor software. No registry or registrar is involved.
Why can't my browser open .onion links?
Regular DNS never resolves .onion names. You need Tor (for example, Tor Browser) to reach them.
What is .onion used for?
Used to access devices over the Tor network.
Sources
Data from IANA root zone version 2026102000. Last changed October 21, 2026. Spotted something wrong? Tell us.