What Is a .onion Site? A Complete Guide to Onion Addresses
You've seen a web address that ends in .onion instead of .com — a long, unreadable string of letters and numbers that does nothing when you paste it into your browser. Here is what it actually is, why it looks so strange, and why that strangeness is the whole point.
A .onion site is a website that lives inside the Tor network. Where an ordinary website answers to an address like example.com that anyone can reach from any browser, a .onion site answers only to an address ending in .onion — and only from inside Tor. That single difference changes almost everything about how it works, who can see it, and why it exists.
The .onion suffix isn't a normal domain ending like .com or .org. It's what's called a special-use top-level domain: a reserved label that signals "this address is not on the ordinary internet — it's a Tor hidden service." No registrar sells .onion addresses, and no central authority hands them out. As we'll see, a site essentially generates its own.
Why the address looks like random gibberish
This is the question almost everyone asks first. A modern .onion address looks like this:
Because the address is generated from cryptography rather than chosen like a domain name, it can't be a friendly word — it's an unguessable fingerprint. And that has a profound side effect: the address itself proves you're connected to the real site. There's no certificate authority to trust, no DNS to spoof; if you reach that exact 56-character address, you are cryptographically guaranteed to be talking to the site that holds the matching key. Security is baked into the name.
"An .onion address isn't a name pointing at a site. It's the site's identity, wearing the address as proof."
Why it won't open in Chrome or Safari
Paste a .onion address into your normal browser and you'll get an error, because that browser has no idea how to find it. Ordinary browsers look up addresses through the global DNS system — the internet's phone book. .onion addresses simply aren't in that phone book; they only resolve inside Tor, through a completely separate mechanism. So reaching one requires software that speaks Tor's language:
- Tor Browser — the official, free browser for Windows, macOS, Linux and Android, from torproject.org.
- Onion Browser — the Tor Project's recommended app on iPhone and iPad.
There are also websites that offer to open .onion links inside a normal browser by acting as a middleman. Avoid them: they route everything you do through an unknown third party, which throws away the privacy that .onion sites exist to provide. If you're setting up for the first time, our step-by-step guide to accessing .onion sites walks through it safely.
How a .onion site actually works
Without drowning in technical detail, here's the essence of what happens when you visit one. A normal website request travels more or less straight to a server whose location (its IP address) is public. A .onion connection is deliberately different: your traffic is wrapped in layers of encryption and bounced through several volunteer-run relays, and the site's real location stays hidden too. Neither side learns where the other is. The name "onion" comes from exactly this — layers of encryption wrapped one around another, peeled back one relay at a time.
The result is a connection where both the visitor and the website are anonymous — something the ordinary web was never built to do. That's the capability, and everything else about .onion sites follows from it.
So who actually uses .onion sites?
The reputation is lurid; the reality is more ordinary than you'd expect. Because the same anonymity protects anyone who needs it, legitimate .onion sites are everywhere once you look:
- News organisations. The BBC, The New York Times and ProPublica run official .onion mirrors so readers in censored countries can reach their journalism.
- Whistleblowing platforms. Newsrooms worldwide use SecureDrop, a .onion-based system, to receive documents from anonymous sources.
- Privacy services. Proton Mail, DuckDuckGo and the Tor Project itself all operate onion services.
- Ordinary people in places where the open internet is monitored or filtered, using Tor to read, communicate and browse without exposure.
Yes, the anonymity that serves those users also shelters criminal activity — that part of the reputation isn't invented. But "a .onion site" is no more inherently illegal than "a website" is. It's neutral infrastructure. For a curated set of trustworthy ones, see our directory of legitimate .onion sites.
How do you find .onion sites?
Since there's no registrar and no Google for Tor, discovery works differently. You can't stumble onto .onion sites the way you browse the open web — you either already know an address, or you search for one with a tool built for the job. That's what a dark web search engine does: it crawls the Tor network and lets you search the hidden services it finds.
Ready to explore .onion sites for yourself?
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Frequently asked questions
What is a .onion site, in one sentence?
A website hosted inside the Tor network, reachable only through Tor, whose address is generated from its own cryptographic key rather than registered with any domain provider.
Why are .onion addresses 56 random characters?
Because the address is derived from the site's public key, making it both unguessable and self-verifying — reaching the exact address proves you're on the genuine site. The cost is that addresses can't be memorable words, which is why phishing clones are a risk.
Why won't a .onion link open in my normal browser?
.onion addresses aren't in the ordinary DNS system, so Chrome, Safari and Firefox can't find them. Use Tor Browser, or the Onion Browser app on iOS. Avoid "proxy" sites that open them in a normal browser — they see all your traffic.
Are .onion sites illegal?
No. The technology is neutral and widely used by legitimate organisations, from the BBC to Proton Mail. Visiting .onion sites is legal in most countries; only specific illegal activity on a given site would break the law.
Is a .onion site the same as the dark web?
.onion sites are the main part of what people call the dark web — the websites hosted on Tor. The dark web is the collection; a .onion site is an individual address within it.