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.
It matters less here than for some of this workspace's applications and more than you might think. An expression is rarely secret; a matrix of measurements from an experiment, a list of identifiers being compared as two sets, or a table of readings being interpolated between often is, and none of it goes anywhere.
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 a staff list on a shared computer — clearing your browsing
data removes it, and a private window keeps nothing at all. 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.
Shoe, clothing, ring and bra sizes are conventions rather than measurements. Every maker adjusts them, and the same nominal size differs by a whole step between two shops on the same street. What these tools convert is a number; the thing that decides whether something fits is the measurement it was derived from, which is why every one of them gives that too and tells you to check it against the maker's own chart.
A cup is four different volumes, a tablespoon three, a gallon two, a pint two and a gigabyte two. The system is yours to choose rather than ours to guess, and every answer says which one it used — because a recipe almost never does, and the difference between a US and an imperial pint ruins a batter.
Flour scooped from the bag is a fifth heavier than flour spooned and levelled, and no converter can know which you did. The tools that turn a volume into a weight give the spread as well as the middle, because that spread is the reason serious baking books ask for grams.
Some of these refuse rather than answering, and that is deliberate. The wire gauge tool gives no current rating: what a conductor may safely carry depends on its insulation, how it is installed, whether it is bundled, the ambient temperature and the wiring regulations where you are, and a figure from a web page would be read as permission. The screw tool shows no fine pitch where the standard lists none, rather than inventing a thread nobody sells a tap for.
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.