What you type never leaves your device. Every one of these tools is compiled to WebAssembly and runs inside this browser tab. There is no server to send anything to, and none of them makes a network request while it works. You can open your browser's network panel and use any of them: nothing goes out.
That matters more here than it looks. The numbers people bring to an investing calculator are a portfolio, a position, a cost basis, a salary being saved out of. None of it is worth uploading, and none of it is uploaded.
Each tool remembers your settings, and remembers your input while it is small enough
to be worth keeping, under about eight kilobytes. It is kept in your browser's own
localStorage, on your machine, and is never transmitted. That is worth
knowing before you paste something you would rather not leave behind — clearing your
browsing data removes it. Your chosen language and theme are stored the same way.
No account, no sign-up, no cookies of our own, no analytics script, no fingerprinting, no error reporting. The pages carry no third-party JavaScript except the advertising described below.
These pages carry advertising, which is what pays for hosting them. An advertising network sets its own cookies and sees your IP address and the page you are on, in the same way it does on any other site. It does not see what you type into a tool: that text is never part of the page's markup and is never sent anywhere. If you would rather it saw nothing at all, an ad blocker breaks none of the tools.
Opening a file reads it into the tab's memory and no further. Saving a result writes it with your browser's own download mechanism. Neither passes through a server.
The same tools are also built as a desktop application. It has no network code at all — not for updates, not for anything — and stores its settings in one small file in your user configuration directory.
If this ever changes, this page changes with it, and the change will be visible in the project's history rather than announced quietly.