Privacy notice

Last updated: 30 September 2026

ChatTorrent keeps as little about you as it can: no accounts, no cookies, no analytics, and your chats are saved only in your own browser. The one thing to know: the AI model runs in other people's browsers, so they can see what you send it. Don't send anything private.

Who runs ChatTorrent

ChatTorrent is a personal, non-commercial project run by lwn, who is the "controller" of the little personal data it handles. For anything on this page, contact [email protected].

Your data can be handled by two quite different groups, and this notice keeps them apart:

• ChatTorrent: lwn, and the three things lwn runs:
  • the website, which delivers the page to your browser;
  • the connection server, which introduces browser tabs to each other so they can link up;
  • the relay server, which passes the encrypted traffic between tabs on, so they don't learn each other's IP addresses.
  Whenever this notice says what ChatTorrent does or doesn't store, it means these, and only these.
• The mesh: every browser tab open on ChatTorrent, yours included. The AI runs here, on visitors' own graphics cards, not on any server. The other tabs belong to other people, and ChatTorrent doesn't control them. The mesh does see and hold what you send while it works on it (see What other people in the mesh can see).

Outside companies supply the infrastructure; see Who else receives data.

What ChatTorrent collects

The only personal data ChatTorrent itself handles is your IP address.

When you open ChatTorrent, the connection server sees your IP address. It uses it for one thing: limiting how many connections a single address can open at once, so nobody can flood the service. It's held in memory only while you're connected, and it isn't written to any log. The site is reached through Cloudflare, which also sees your IP address as part of delivering it (see "Who else receives data" below). The legal basis is a legitimate interest in keeping the service running and protecting it from abuse.

Connections between tabs go through the relay server, so other people's tabs don't see your IP address. The relay does: it records the address, time and a random ID for each connection, to spot and block misuse, and deletes these records after 7 days. The one exception is if you open the site with ?direct=1 at the end of the address, a developer option that connects tabs directly and so shows your address to the tabs you connect to.

What other people in the mesh can see

There's no central server running the AI. Your message and the reply are processed by the browsers of other people connected to the same mesh, on their graphics cards, and they can in principle see or record what passes through them.

• In the global mesh, those people are strangers.
• In a private mesh, they're only people who have that mesh's invite link.

Some tabs receive your words directly. Other tabs receive information derived from your words, which isn't your text word for word but can be turned back into it. Every tab that helps run your chat keeps some of this in memory between messages (see The KV cache below), so treat all of it as though it were your chats.

Between tabs, your messages travel encrypted through the relay server, which passes them on but can't read them. So lwn and ChatTorrent's servers never see, store or have access to your messages: only the mesh does.

Please don't send anything sensitive or personal, especially in the global mesh.

The KV cache

An AI model rereads the whole conversation every time it writes the next word. So that it doesn't start from scratch each time, every tab that runs part of the model keeps notes on the conversation so far in its graphics card's memory. These notes are called the KV cache.

• What's in it: not your words as written, but numbers calculated from them. With the right tools, those numbers can be turned back into the text, so treat the KV cache as a copy of your conversation.
• Who holds it: every tab that helped run your chat holds the notes for its own part of the model. If you contribute your GPU, your tab holds them for the chats it helps run. The page never shows them to you.
• How long it's kept: in memory only, never saved to disk. It's cleared when the chat is deleted, when the tab needs the space for another chat after this one has gone quiet, or when the tab is closed or reloaded. Until one of those happens, it stays. ChatTorrent has no control over this.
• What ChatTorrent can't promise: someone running a modified version of the page could save it.

What you store

In your browser

Your browser keeps these, and never sends them anywhere:

• Your saved chats, so you can come back to them. Delete them with "Forget this mesh's chats" in the chat list, or by clearing this site's data in your browser.
• Whether the chat list is shown or hidden.

They're only there because you asked for what they do, so no consent banner is needed. ChatTorrent uses no cookies, analytics, advertising or tracking of any kind.

If you contribute your GPU

Your browser only uses your graphics card if you choose to in the welcome popup, and only up to the amount you pick. It then downloads part of the AI model from weights.chattorrent.net (hosted on Cloudflare, which sees your IP address when you download). Other tabs in the mesh learn a random ID for your tab and which part of the model it holds, nothing more. If someone turns on the optional profiling tool in Settings, the name of your graphics card (e.g. "NVIDIA GeForce GTX 1070 Ti") is shown to them for the requests your tab helped run.

While your tab helps run other people's chats, it holds their KV cache in your graphics card's memory, as described in The KV cache. It's never saved to disk, and closing the tab clears it.

Who else receives data

• Cloudflare delivers the website and hosts the AI model's files. It sees IP addresses as part of this. Cloudflare's privacy policy.
• Hetzner hosts ChatTorrent's relay server, in the EU. It provides the machine only and doesn't use the data for anything else. Hetzner's privacy policy.
• Other people in your mesh run the model, as described above.

No data is sold or shared with anyone else.

Transfers outside the UK

ChatTorrent's relay server is in the EU, which UK law recognises as protecting personal data adequately. Cloudflare operates worldwide, so your IP address may be processed outside the UK. Cloudflare protects such transfers with the safeguards UK law requires; its privacy policy has the details. Other people in the mesh can be anywhere in the world, and your messages reach whichever of them are running the model at the time.

How long data is kept

• Your IP address: on the connection server, only while you're connected; in the relay server's records, 7 days.
• Your messages: never stored by ChatTorrent. The mesh holds them while it works on them, and the people in it could keep what passes through their tabs, which ChatTorrent can't control.
• The KV cache other tabs hold for your chat: in their memory only, never on disk. See The KV cache for when it's cleared.
• Saved chats and settings: in your browser, until you delete them.
• Cloudflare keeps its own records according to its privacy policy.

Your rights

Under UK data protection law you have the right to ask what personal data is held about you, to have it corrected or deleted, and to object to how it's used. In practice, the only thing ChatTorrent holds about you after you disconnect is the relay server's record of your IP address, for 7 days. Your chats are in your own browser, where you can delete them yourself. Other tabs in the mesh may still hold your chat's KV cache for a while; ChatTorrent can't reach it, and it's cleared as described in The KV cache. If you have a question or a request, email [email protected].

You can also complain to the Information Commissioner's Office: ico.org.uk/make-a-complaint.

Children

ChatTorrent is for adults only. You must be 18 or over to use it.

Changes to this notice

If this notice changes, the date at the top will change too. If ChatTorrent ever starts collecting anything new, this page will say so before it does.