ctrans by chloro

REQUIRES A COMPANION APP

ctrans is the browser half of a two-part tool. You also need to run the ctrans service and a
local language model on the same computer. Setup takes a few minutes and is described at
https://github.com/Chloro989/ctrans — if you are not willing to do that, this extension will
not work for you.

WHAT IT DOES

Translate or summarize a whole page, or just the part you selected, using a language model
running on your own machine. Click the toolbar icon or use the right-click menu. The result
appears in a panel you can move and resize; the page itself is never modified.

Languages: Japanese, English, Simplified Chinese, Traditional Chinese, Korean, Russian,
Spanish.

No cloud service. No account. No API key. No usage limits. It keeps working with the network
unplugged.

WHERE YOUR DATA GOES

To 127.0.0.1 — your own computer — and nowhere else.

The extension holds no permission to reach any other address, and its settings page refuses
any address whose host is not 127.0.0.1. It reads a page only when you invoke it, never in the
background. No analytics, no telemetry, no accounts, and the developer operates no servers and
receives nothing.

BUILT FOR HOSTILE PAGES

A web page can contain text aimed at the language model rather than at you, hidden where you
will never see it: white text on a white background, elements pushed off screen, words split
by invisible characters, instructions smuggled inside Unicode control characters.

ctrans removes what you cannot see before anything is sent, and normalizes what you cannot
read. But filtering is not the defense, because no filter reliably detects an instruction
written in ordinary prose.

The defense is the shape of the request. The translation call is built with no tools, no
function calling, no conversation history, no filesystem access, and no network access beyond
the one local endpoint. A model that does follow an injected instruction has nothing to act
on.

The model's output is treated as untrusted in turn: it is rendered as plain text inside a
closed shadow root, never as HTML.

OPEN SOURCE

MIT licensed. https://github.com/Chloro989/ctrans