Understand
An extension for Chrome, Edge, Firefox and the browsers built on them. It sees what the application cannot — Gemini, Meta AI, Copilot in Microsoft 365 — and hands the result over to it. Free, no account, and nothing leaves the machine.
From your browser's store. Brave, Arc, Comet, Opera and Vivaldi take the extension from the Chrome Web Store.
Safari is not supported yet: it only accepts an extension wrapped in a dedicated application, which remains to be built.
The CarboneWatch application, installed alongside, does the rest on its own: at start-up, it allows the extension to hand over its measurements, in every browser present on the machine. Its settings say which ones.
CarboneWatch recognises AI services by their network address, never by host name: that is what lets it decrypt nothing and read no content. The price of that choice is that a service served from someone else's addresses escapes it.
Gemini is served from Drive and Gmail's addresses. Meta AI from Facebook's. Copilot from Office's. Counting them by address would mean billing a photo backup as inference, so the application alone does not count them. The extension can tell them apart.
On its own, the extension shows the volume exchanged per service in its panel, and keeps it for forty-eight hours. It computes neither electricity nor carbon: that is the application's job.
With the application, these measurements enter your estimate, alongside everything the application sees by itself. The extension's panel, in French for now, confirms it: "Remis à l'application", with the time of the last handover. Only closed hours are handed over: the first appears once the current hour has ended.
| Browser | Where to install it |
|---|---|
| Chrome, Brave, Arc, Comet, Opera, Vivaldi | Chrome Web Store |
| Microsoft Edge | Microsoft Edge Add-ons |
| Firefox (version 140 or later) | Firefox Add-ons |
| Safari | Not yet |
For each request to an AI service on its list, the address called and the number of bytes transferred. Not the content of answers, not the text of pages, not keystrokes: none of it is available to it, and none would leave if it were.
An hour on an AI service transfers the interface, its telemetry and its error reports; the answer itself is often only a fraction of that. Where the service allows the requests carrying the answer to be recognised, that fraction is what the extension puts forward.
Five numbers per hour and per service: the hour, the service, the bytes, the request count, and those whose size the browser did not publish. Nothing else. The precise addresses of the pages visited stay in the browser — they help the extension recognise answers, and they do not cross the bridge.
The handover uses the mechanism browsers provide for it: nothing listens on the machine, nothing goes over the network, and only the CarboneWatch extension is allowed to use it.
The extension collects no personal data. For each request to an AI service on its list, it reads the address called and the number of bytes transferred — nothing else. It has no access to page content, to model answers, or to what you type, and it only runs on the addresses on that list.
What it measures stays on your machine, in the browser's local storage, and erases itself after forty-eight hours. The panel's "Clear" button deletes it at once; uninstalling the extension deletes it too.
It sends it to no server. If the CarboneWatch application is installed, the extension hands it five numbers per hour and per service, through the local mechanism browsers provide — without going over the network. No third parties, no advertising, no analytics, no sale: there is nothing to sell.
Controller: Clément Tournier, NuCom agency, Annecy. For any question: clement@nucom.fr.
