The short version
BMI Compass doesn't collect anything. Here's exactly what that means.
What's stored, and where
BMI Compass saves your data using your browser's built-in localStorage — a small storage area that belongs to your device and browser, not to us. Specifically, it stores:
- Your height and your chosen unit system (metric or imperial)
- Each weight entry you log, along with its date and any short note you add
- Your White/Dark colour theme preference
That's the entire list. None of it is bundled up, summarised, or sent anywhere — it simply sits in your browser the same way a bookmark or a saved form field would.
What we don't do
There is no server behind this app, so there is nothing for it to talk to. Concretely:
- No account or sign-up — there's no identity to create or log into.
- No analytics or tracking scripts that identify you — this copy does keep anonymous, aggregate counts of which features get used (details below), but nothing that identifies you, follows you across visits, or leaves this server.
- No cookies beyond the
localStorageentries described above, which your browser never transmits to us or anyone else. - No selling, sharing, or backing up of your data to any third party, because it never leaves your device in the first place.
The one external request this page makes
The page loads three typefaces (Fraunces, Public Sans, and IBM Plex Mono) from Google Fonts. That's a normal web request to Google's servers to fetch font files — like any site using a web font, your browser's IP address is visible to Google for that request, the same as loading an image from any other website would be. No BMI or weight data is included in that request; it's purely a font file download. If you're using the downloadable package and would rather make zero external requests at all, its fonts/README.md walks through self-hosting the same fonts locally in a couple of minutes.
The one anonymous count this self-hosted copy keeps
This particular copy of BMI Compass — the one running on this domain — also keeps a small, anonymous tally of how often a handful of features get used: for example, how many times the goal-weight form was submitted today, or how many times the print-a-summary button was clicked. Those counts live in a database on this same server and are never shared with anyone else, any company, or any third party. What's recorded is only an event name and a calendar date — never your height, weight, waist measurement, notes, or anything else you've entered, and never anything that could tie a count back to you individually: no IP address, no cookie, no session identifier, nothing that distinguishes one visitor from another. It can answer "how many times did X happen today," and nothing else — there is no way, even in principle, to reconstruct an individual visit from what's stored. This is separate from, and far more limited than, services like Google Analytics.
Your data is yours to control
Because everything lives in your browser, you're already in full control of it:
- Use the Delete all option in the app to clear every entry at once.
- Clearing your browser's site data/cookies for this page removes everything BMI Compass has stored.
- Using a different browser or device starts with a clean slate — data doesn't sync between them, since there's no account or server to sync through.
Changes to this policy
If what this app stores or requests ever changes, this page will be updated to describe it accurately. Since there's no account system, we have no way to notify you directly — check back here if you want to confirm the current behaviour.
Questions
BMI Compass is a small, self-hosted, static tool rather than a company product, so there's no support desk behind it. If you're self-hosting the downloadable package yourself, this policy describes the app's default behaviour as shipped — review the source (it's a single readable HTML file) if you want to verify any of the above for yourself.