Data and privacy
Where the numbers you type go
Not a statement of intent. Every kind of data touched here, set out four ways: what it is, what it is for, where it sits, and who can clear it.
- Data
- Age, sex, height, weight, head and arm circumference
- Purpose
- Working out this one reference position
- Where
- The browser on your device. The reference tables download with the page, so the calculation itself never goes online.
- Control
- A Clear button sits under the input card on every calculator; one press removes all of it.
- Data
- The same figures, held between pages
- Purpose
- So you do not retype them on the next page
- Where
- Your browser’s localStorage, under tendcare.child.v1. This device only — not synced, not uploaded.
- Control
- The same Clear button, or clearing site data in your browser.
- Data
- Milestone checkboxes
- Purpose
- Counting what is ticked and which domain the gaps fall in
- Where
- This page view only. A refresh clears them; they are stored nowhere.
- Control
- Nothing to clear — they stop existing when you leave.
- Data
- Page views
- Purpose
- Knowing which pages get read
- Where
- Vercel Analytics. It records which URL was visited, never anything you typed.
- Control
- Browser Do Not Track settings and content blockers both stop it.
What does not happen
- No sign-up, and no accounts
- No uploads — not reports, not photos, not files of any kind
- No dates of birth or measurements in the URL, so a shared link carries none of a child’s data
- Nothing you type is sent to any third party
- No diagnosis, and no instruction to seek care
Third parties in use
- Vercel — hosting and page-view counts
- Nothing else. No advertising scripts, no social widgets, no third-party fonts.