It estimates the carbon footprint and water of your AI use in the browser, including services the desktop application cannot tell apart on its own. Free, no account, and nothing sent to any server.
The extension recognises the AI services you use in the browser, for example Gemini, Copilot in Microsoft 365 or Le Chat.
For each one, it records the volume of data exchanged, from what the browser publishes for each request, without reading what the pages or the answers contain.
From that, it derives an estimate of carbon and water, with a range, calculated by the same method as the application.
It calculates the estimate itself and shows it in its panel, for the last twenty-four hours, and on its full page, over seven and thirty days.
It only sees the services open in the browser where it is installed.
It hands its hours over to the application, which adds them to everything it sees on the machine. What the application already counted is not counted twice, and the application's figures prevail.
The panel says so: “Connected to the app”, with the time of the last handover. If the two do not calculate with the same method, it says which one to update.
From your browser's store or, for Safari, from this site. Brave, Arc, Comet, Opera and Vivaldi take the extension from the Chrome Web Store.
Safari only accepts an extension carried by an application. This one, “CarboneWatch for Safari”, is small, signed and notarised by Apple, and does nothing else.
Before Safari 18.4, the extension only appears after ticking “Allow unsigned extensions” in Safari's developer settings.
On those websites, the address of each request and the number of bytes transferred. Of the address, it only keeps the service and the shape of the path, which is used to recognise answers. That per-path detail erases itself after forty-eight hours; the hours, after thirty days.
Nothing, as long as it is on its own: it sends nothing to any server, and its records stay in the browser's local storage. The “Clear” button deletes them at once; uninstalling the extension deletes them too.
Connected to the application, it hands it five numbers per hour and per service, through the local mechanism browsers provide, without the network; those hours then follow the application's sharing settings. It collects no personal data: no account, no advertising, no analytics.
Controller: Clément Tournier, NuCom agency, Annecy. Contact: clement@nucom.fr
The desktop application, for macOS, Windows and Linux, sees the AI services of the whole machine, beyond the browser. Installed together:
