Learning Path
Tor Technology Fundamentals
Tor is a piece of technology that most people have heard of and few understand. This path goes one step deeper than the dark web overview: how the network is built, what each part does, how onion routing actually works, and how Tor compares with the other anonymous networks. It is written for readers who want to understand the technology itself — and, just as importantly, what it cannot do.
How this path works. Each lesson below is a short summary written for this path, with a link to the full guide. Work through them in order, mark each one complete when you have read the guide, and test yourself with the quiz at the end. Your progress is stored only in your own browser — no account, nothing sent to us. This path teaches understanding, not credentials: completing it does not give you a certificate and does not qualify you for a job.
What you will learn
This path is for readers who want to understand the technology behind the dark web stories. It assumes you are comfortable with the basics from the dark web path, but it still explains every term when it first appears. It does not teach you how to run a relay or hide your activity — it teaches you how the system works.
- Explain Tor Browser, the Tor network, relays and circuits in plain English.
- Describe onion routing layer by layer, and say what each relay learns.
- Compare Tor with I2P and Hyphanet honestly, including what each one is for.
- Know how to download Tor Browser safely, from the official source only, and verify it.
- Explain the difference between Tor and a VPN, and why using both is not automatically safer.
- State Tor's real limits: exit visibility, speed, site blocking, and correlation attacks.
Your progress
0 of 7 lessons complete.
The lessons
Read each lesson summary, then open the full guide it links to. The summaries are written for this path — they do not repeat the guides, they prepare you for them.
Lesson 1: Tor Browser explained
Tor Browser is a web browser built for privacy, based on Firefox, that routes your connection through the Tor network. This lesson explains what it is and what it is not: it is a browser with privacy settings built in — it blocks trackers, resists fingerprinting, and routes through Tor — but it is not a magic shield. It protects the connection, not the choices you make inside the browser, and understanding that boundary is the lesson's real point.
You will learn how Tor Browser differs from an ordinary browser with a VPN switched on, why it looks the same on every computer (so every user looks alike), and why some sites behave oddly in it — asking for more verification, loading slowly, or refusing to work at all. Those quirks are the price of the design: making every user look identical is itself a defence, and the lesson explains why it matters.
Read the full guide: Tor Browser explained
Lesson 2: How Tor works
This lesson is the core of the path: the Tor network, step by step. Your connection passes through three volunteer-run relays — guard, middle and exit — chosen by your Tor software. Each relay knows only the step before and after it, so no single relay knows both who you are and where you are going. That separation of knowledge is what the whole network is built around.
You will learn the role of each relay in detail: the guard sees your address but not your destination, and stays the same for weeks so that changing guards cannot be used to track you; the middle relay sees neither end; the exit relay sees the destination and the traffic it carries, which is why encryption matters so much at the exit. The lesson uses the interactive circuit visualizer from our tools so you can click through a circuit and see each relay's view for yourself.
Read the full guide: How does Tor work?
Lesson 3: How onion routing works
Onion routing is the technique underneath Tor, and this lesson is its deep dive. Before your message leaves your computer, it is wrapped in three layers of encryption — one for each relay. The guard relay removes the outermost layer and learns only where to send the message next. The middle relay removes the next layer. The exit relay removes the final layer and delivers the message to the destination.
You will learn why the route is chosen by your software before the message is sent, rather than by the relays as it travels; why each relay only holds a key for its own layer; and how onion services — the .onion sites — use the same idea in reverse, meeting your connection inside the network so neither side learns the other's address. The technique is conceptually simple, which is part of its strength: there are fewer moving parts to go wrong than people expect.
Read the full guide: How onion routing works
Lesson 4: Can you be tracked on Tor?
Tor makes tracking much harder, and this lesson explains the honest boundary between harder and impossible. Your internet provider can see that you are using Tor but not what you are doing. The website you visit sees the exit relay, not your address. But the exit relay can see unencrypted traffic, and an observer who can watch both ends of a connection can try to match them by timing — a correlation attack that has been documented since 2005.
The lesson walks through the realistic ways people are identified on Tor, and they are almost all about behaviour rather than broken cryptography: logging into a personal account, downloading a file that connects outside Tor, or using the same distinctive writing style and details that identify them elsewhere. The takeaway is a balanced one — Tor is a serious privacy tool used by journalists, researchers and ordinary people, and it is most effective when you understand what it does and does not hide.
Read the full guide: Can you be tracked on Tor?
Lesson 5: Tor vs I2P vs Freenet
Tor is not the only anonymous network, and this lesson compares it with the other two that matter: I2P, built for hidden services and peer-to-peer traffic, and Hyphanet — the network formerly called Freenet, renamed in 2023, which many older guides still call by its old name. Each was designed for a different purpose, and comparing them by a single score misses the point.
You will learn the design differences in plain terms: Tor is best for browsing the ordinary web anonymously, I2P is built around services that live inside the network, and Hyphanet is built around censorship-resistant publishing and file sharing — three different designs for three different jobs, not three versions of the same thing. The lesson is dated and corrected — the Freenet rename is noted explicitly — and it ends with the honest summary: there is no single best anonymous network, only the one that fits what you are trying to do, and none of them guarantees anonymity.
Read the full guide: Tor vs I2P vs Freenet
Lesson 6: How to download Tor Browser safely
If you ever download Tor Browser, there is exactly one safe source: the Tor Project's own website, torproject.org. This lesson explains the whole safe path — go to the official site, download only from there, and verify the download's signature file before you install it. Signature verification sounds technical, but the lesson walks through it in plain steps: it proves the file you downloaded is the file the Tor Project published, and not a modified copy from a mirror or a search result.
The lesson also explains what not to do: never download Tor Browser from a mirror, a third-party download site, or a link in a message or a video. Those are the routes by which modified, malicious copies circulate, and they are a real attack route — not a hypothetical one. And it sets expectations honestly: Tor Browser is slower than an ordinary browser, some sites will challenge you more often, and none of that means something is wrong.
Read the full guide: How to download Tor Browser safely
Lesson 7: Tor vs VPN: what each hides
Tor and a VPN both hide things, but they hide different things from different people, and this lesson lays the difference out plainly. A VPN hides your browsing from your local network and your provider, but the VPN provider itself can see it — you have moved your trust from one party to another. Tor spreads the trust across three relays, so no single party sees the whole picture — but it is slower, and the exit relay can see unencrypted traffic.
The lesson tackles the most common misunderstanding head-on: using Tor and a VPN together is not automatically safer. Each combination changes who can see what, and in some arrangements it makes you stand out more, not less. The lesson uses the who-sees-what tool to show the four situations side by side — direct connection, VPN, Tor, and both — so you can judge for yourself instead of taking anyone's word for it, including ours.
Read the full guide: Tor vs VPN
Try the tools
These free tools let you practise what the lessons describe — everything runs in your browser, and nothing you type is sent anywhere.
- Tor Circuit Visualizer — click each relay to learn what the guard, middle and exit relay can and cannot see
- Who Sees What? Packet Journey — follow one web request and see what each party can see, with HTTPS, VPN and Tor toggles
Check what you learned
Four questions, all based on fictional scenarios. Answer them all, then check your score — each answer explains itself, so a wrong answer teaches as much as a right one.
Answer all four questions, then check your score.
Download your notes
Download a plain-text summary of this path: the lesson list, which lessons you marked complete, and your quiz score. The file is generated on your device — nothing is uploaded.
Key terms in this path
The glossary defines every term this path uses: Tor, onion routing, VPN, encryption. If a lesson uses a word you do not know, look it up there — each term page also explains the idea with an example.
Frequently asked questions
Do I need to use Tor Browser to learn Tor?
No. This path teaches how Tor works — you can follow the whole path and use the circuit visualizer without ever installing anything. If you do want to download Tor Browser later, the download lesson explains the official-source-only path and signature verification.
Is Tor only used by criminals?
No. Tor is used by journalists, researchers, human-rights workers, and ordinary people who want privacy — as well as by criminals, like every widely used technology. This path treats Tor as a technology to understand, and is explicit that criminal use of it is still criminal.
Why is Tor slower than normal browsing?
Because your traffic passes through three volunteer-run relays around the world instead of going directly, and each relay adds delay. The volunteer network also has limited capacity. Slowness is the normal price of the design, not a fault.
What is the difference between Tor Browser and the Tor network?
The Tor network is the volunteer-run relay system that routes traffic. Tor Browser is a web browser that uses that network, with privacy settings built in. Other programs can use the network too, but the browser is the way most people meet it — and this path covers both.
Why do some sites block Tor or ask for extra checks?
Because exit relays are shared by many users, sites see a lot of traffic from a small number of addresses, and some of it is abusive. Sites respond with extra verification or blocks. It is a known trade-off of the design, and the path explains it rather than pretending it does not happen.