What Are Onion Sites, Or On The Dark Web?
Websites that exist entirely within Tor's own network, reachable only through Tor Browser and a very different kind of address.
An onion site is a website hosted as a Tor hidden service — reachable only through the Tor network via a special .onion address, never through a regular browser or standard internet routing. Both the visitor's connection and the site's actual server location stay anonymized, which is what separates onion sites structurally from anything on the ordinary web, hidden or not.
A regular website has a public IP address somewhere, sitting on a server that anyone's browser can eventually find its way to.
An onion site doesn't work that way at all — it doesn't have a normal public address, and no amount of clever Googling will ever surface one.
TL;DR
Quick answer
An onion site is a website hosted as a Tor hidden service, reachable only through a .onion address and Tor Browser. Unlike a regular hidden page, both the visitor and the site's host remain anonymous to each other by design.
The setup
Not a hidden door on a normal house — a house built without an address at all
The easiest mistake is picturing an onion site as a regular website that's just been made hard to find. It's actually a structurally different kind of website. A normal site publishes its server's IP address so browsers know where to send requests. An onion site never does that — instead, it publishes a long cryptographic address that only makes sense within Tor's own routing system.
When you visit one, your connection and the site's actual server location both get routed through several layers of Tor relays, meeting in the middle without either side ever learning the other's real network location. That mutual anonymity — not just secrecy about a URL — is the actual defining feature.
What makes an onion site different, mechanically
- No public IP address is ever published or discoverable.
- Both visitor and host remain anonymized to each other, not just to outside observers.
- Only Tor-compatible software can resolve or reach a .onion address at all.
Even the site's operator doesn't have to know where their own server physically is
This mutual anonymity is why onion sites are described as 'hidden services' rather than just 'hidden pages' — the hiding applies to both ends of the connection.
Because onion sites are routed through Tor's anonymizing layers on the hosting side too, it's technically possible for an operator to run a site without ever needing to know or reveal the server's actual physical location themselves — a level of anonymity that goes well beyond just hiding a URL.
It explains why onion sites can be so resilient against certain kinds of takedown attempts, even when a URL becomes widely known.
The mechanics of an onion address
What's actually happening when you visit a .onion URL.
The address is generated from a cryptographic key
Modern .onion addresses (v3) are derived from the site's own public key, not chosen or registered like a normal domain name.
The site announces itself within Tor, not the public internet
It publishes its availability to Tor's internal directory system rather than to a domain registrar or public DNS.
Visitor and host connect through a meeting point
Both sides route through Tor relays that meet at a point neither party fully controls, so neither learns the other's real network location.
Why do onion addresses look like random gibberish instead of a normal name?
A regular website gets a readable name like example.com. Why do onion addresses look like a long meaningless string instead?Because the address itself is the security mechanism, not just a label. It's mathematically derived from the site's cryptographic key, which lets Tor verify you've actually reached the real site — rather than an impersonator — without needing any central authority to vouch for it, the way a domain registrar does on the regular web. The unreadability is the trade-off for not needing to trust anyone in the middle.
Major news organizations run their own official onion sites
Outlets including the BBC maintain official .onion versions of their websites, specifically to remain accessible to readers in countries where the regular internet is censored or monitored.
It's a clear counterexample to the assumption that onion sites are inherently illicit — some of the most mainstream, reputable publishers in the world maintain one.
The least discoverable part of the internet is also one of the most permanent-feeling
Regular websites disappear constantly when domain registrations lapse or hosting bills go unpaid. A properly maintained onion address, tied to a cryptographic key rather than a rented domain name, can in principle persist indefinitely without needing to renew anything with a third party at all.
ProPublica's onion site
The investigative journalism outlet ProPublica has maintained an official onion mirror of its site specifically to protect the anonymity of readers researching sensitive topics.
It shows onion sites being used deliberately as a reader-protection tool by a mainstream journalism organization, not just by anonymous operators.
So, what is an onion site, simply?
A website that exists entirely within Tor's network, reachable only through a cryptographically derived address that keeps both visitor and host anonymous to each other.
Not a hidden page on the regular internet — a structurally different kind of website altogether.
Anonymity had to be built into the address itself
Onion sites are a reminder that meaningful privacy sometimes can't be bolted onto an existing system — it has to be designed in from the very first layer, including something as basic as how a website gets its name in the first place.
The short version
- Onion sites exist entirely within Tor's network, with no public IP address.
- Both visitor and host remain anonymous to each other, not just to outside observers.
- .onion addresses are derived from cryptographic keys, not registered like normal domains.
- Legitimate organizations, including major news outlets, maintain official onion sites.
Questions people ask
Where to go next
What are onion sites used for?
The purpose side of this same technology, covered in more depth.
What are dot onion sites, or Tor onion sites?
A closer look at the address format itself.
How to see the dark web
The practical steps for actually reaching a site like this.
What is a bridge relay in Tor?
The related piece of Tor infrastructure that helps some users reach onion sites at all.
Deep web vs dark web: what's the real difference?
The broader context onion sites fit into.
It was never really hiding — it just never had an address to begin with
An onion site isn't a secret page tucked away somewhere. It's a different kind of website, built from the ground up without a public front door.
You now know
- Onion sites exist entirely within Tor's network, with no public IP address.
- Both visitor and host remain anonymous to each other, not just to outside observers.
- Legitimate organizations, including major news outlets, maintain official onion sites.
Safety note
Educational, not operational
This guide is educational. It does not provide instructions for illegal activity, evading law enforcement, buying prohibited goods, or attacking systems. Laws and risks vary by country, so stay within your local rules and avoid interacting with unknown services.
FAQs
Questions people ask
Sources
Further reading
- Tor Project: Onion ServicesTor Project
Glossary
Terms in this guide
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