Privacy
Last updated: September 2026
CALCULA is built to collect as little as possible. Here is what actually happens when you use the site.
Your calculations stay on your device
Every calculation (algebra, geometry, physics, statistics, orbital mechanics…) runs directly in your browser, through a scientific engine (Pyodide/SymPy) executing locally. No expression, equation or result you type is sent to a server.
History
Your calculation history is kept only in your browser's local storage, on your own device. It is never sent anywhere, and it disappears if you clear this site's data in your browser or use the history's “clear” button.
No third-party resource is loaded automatically
The page loads nothing from another site. The scientific engine (Pyodide and its Python libraries), the typefaces and every display library are served by calcula.ch itself. No content delivery network, no font provider, no analytics: opening the page tells nobody about your visit but the site's own hosting.
There is one exception, and you trigger it yourself: if you ask for an optional Python package to be installed (say pandas or astropy, from the closed list the application offers), that package's name goes to the Pyodide package repository, which returns the archive. Nothing from your document goes with it, and the download is then cached by the site.
The files you import
“Import data” reads your file (CSV, TSV, spreadsheet, pasted table) in the browser. It is not uploaded: its contents become variables of your document, and stay where your documents are — on your device.
The share link
“Copy a share link” puts the entire notebook in the address itself, compressed. No server stores it, and that is also what to know before publishing such a link: whoever gets it gets the document. A link stays valid indefinitely, since it depends on nobody.
Hosting logs
Like any website, the host (Infomaniak — see the legal notice) may keep standard technical connection logs (IP address, date and time, pages visited) for security and for the proper running of the service.
No account
The site asks for no account and no sign-up in order to be used.
No advertising, no cookies
The site shows no advertising and sets no cookie — not for advertising, not for analytics, not even a technical one. There is therefore no consent banner to display: there is nothing to consent to.
What the site keeps of you fits in your browser's local storage (your documents, your language, your calculation history), on your device, and nowhere else.
Your questions
For any question about the privacy of your data, see the Contact page.
This page describes how the site actually works today, as honestly as possible; it is not legal advice. It will be revised if the site changes.