Data and privacy
Where the numbers you type live, what they are used for, and who can clear them.
What you type is used for this calculation only
Everything runs in the browser on this device. A security policy closes the route for sending data out, so the browser enforces it rather than anyone promising it. Reload or clear, and the numbers are gone.
What search engines can find
The explanations, methods and sources on the tool pages are public and should be findable. Birth dates, measurements, pasted text and computed results never reach a URL, the page body or the sitemap — they never left this device, so there is nothing to index.
Keeping a result takes a deliberate act
A result goes no further than this page unless you press Copy or print from the browser. No shareable link carrying a child’s numbers is ever generated.
Page views are counted, and here is what with
Page views go through Vercel Analytics, which records which URL was opened and when. No cookie is set, no cross-site identity is built, and nothing you typed can reach it — those numbers never left this device. Page views are all that is counted. Claiming “no tracking at all” would be inaccurate, so that claim is not made.
The note box on the app page is the one exception
There are two buttons and a note box on /app. Only when you press one, type something and hit send does that text leave this device: first to this website’s own server, which passes it to Formspree, the form service that stores it. Contact details are optional — leave them blank and nobody knows who wrote it. Measurements typed into the tools never take this route: the browser’s security policy still refuses to let them be sent anywhere.
What the host can see
Computing in the browser does not mean the hosting server has no access logs. The server knows which URL was visited and when — but no number you typed is in that URL.