Privacy
This site sets no cookies, loads nothing from another domain, and has no analytics. Opened in a clean browser it makes requests to exactly one host — this one — and writes exactly one thing to your browser’s storage, described below. That is the whole of it, and it is checkable: open the network panel and count.
Behaviour verified · How we check
What stays in your browser
One entry, rulecalc.history.v1, holding the last eight answers this browser worked out so they can be listed at the foot of a calculator. It never leaves the device, is not readable by this site’s server, and does not follow you to another browser. The Forget these control removes it, and so does clearing site data.
What the server keeps
- Web server log
- Every request writes one line: the time, your IP address, the path, the response code, how long it took, and the browser string. It is how we know whether a page is broken or whether a search engine has visited. Rotated and deleted after 30 days.
- Helpful votes
- Answering “Did this answer your question?” stores the page, the answer, and a one-way hash of your IP address combined with a server-side secret. The hash exists to stop one person voting twice; it cannot be turned back into an address, and no raw address is kept.
- Questions the catalogue could not answer
- When the chat has no calculator for a question, the question text is recorded so the missing calculator can be built. No identifier is stored beside it. Questions the catalogue does answer are not recorded at all.
- Saved projects
- Only if you press save. The calculation and its title are stored and given a URL; anyone with that URL can read it. Nothing links it to you.
What leaves this site
One thing does. Asking the chat a question sends that question — and any photo you attach — to OpenRouter, which routes it to a language model. The model chooses which calculator to run and reads back the parameters; it never does the arithmetic, and the number you get is computed here. If you would rather nothing left at all, every calculator on the site works without the chat.
Requests also pass through Cloudflare, which sits in front of the site and sees the same request line the server does.
What this site does not do
- Set cookies. Not one, including for this site’s own use.
- Load anything from another domain — no analytics, no tag manager, no hosted fonts, no embedded video.
- Run an advertising script, or sell or share anything with an advertiser.
- Ask you to create an account, or offer one.
- Ask for consent, because there is nothing here to consent to.
Corrections and questions
This page describes how the software behaves. It is a factual disclosure rather than legal advice, and if it ever disagrees with what the site actually does, the page is the thing that is wrong and worth reporting.
There is no published email address yet. The Did this answer your question? control at the foot of each calculator is the route, and it records which page the report came from.