Privacy Policy

Babypercentiles is built so you can use it without handing over anything about your child. We run no accounts, we never ask for an email address, and we set no tracking cookies. Most importantly, the measurements you type into the chart tool are processed entirely on your own device and are never uploaded. This policy describes exactly what happens to data when you use the site, and it describes only things we actually do.

Your child's measurements never leave your browser

This is the core promise of the site and it is literally true in the code. The WHO and CDC parameter tables are downloaded once with the page, and the percentile arithmetic runs inside your browser using those tables. When you press the button to plot a measurement, no request is sent: there is nowhere for one to go, because the calculation has already happened on your device. We never see, store, or transmit an age, a weight, a length, a head circumference, a date of birth, or a resulting percentile.

Nothing is stored between visits

The tool deliberately persists nothing. It does not write your entries to localStorage, to a cookie, or to any other browser storage, so there is no saved copy of a previous session waiting on the next visit. Closing or reloading the tab clears whatever you typed. There is no account to delete, because there is no account and no stored record to delete.

What we do receive: anonymous usage counts

So we can tell whether the tool is being used at all, the site sends a small, anonymous event when a chart is plotted. Because your entries stay on your device, that event is not your data. It carries only:

• Which measurement you were plotting, meaning weight, length or head circumference.
• How many points were plotted, as a count.
• Which unit system was selected, metric or US customary.
• Which reference the chart drew, meaning WHO only, or WHO and CDC.

There is no age, no measurement, no date, and no percentile in it, and no identifier of any kind. Because that event does leave your device, we do not claim that "nothing is uploaded." We claim the specific, true thing: your child's numbers are never uploaded, and what we receive is an anonymous count with nothing in it that could describe a child.

Analytics

We measure aggregate traffic with Umami, a privacy-focused analytics tool we host ourselves at umami-analytics-puce.vercel.app. It is cookieless: it does not set cookies, does not fingerprint you, and does not build a cross-site profile. The anonymous usage event described above is sent through the same tool. No analytics data is sold or handed to an advertising network.

What we do not collect

• No user accounts, logins, or profiles.
• No email sign-up, newsletter, or contact form that stores your address.
• No advertising cookies, tracking pixels, or third-party ad networks.
• No health information, because we never receive any.
• No sale or sharing of personal information, because we hold none.

Third-party hosting

Like any website, our host and content-delivery network process the standard server request data, such as your IP address, needed to deliver the page to you. This is ordinary web infrastructure, is not used by us to profile you, and is not combined with any other data about you.

Links to the WHO and the CDC

Several pages link to who.int and cdc.gov so you can read the source tables and the official guidance directly. When you follow one of those links, that site's own privacy policy applies, and we do not control it. We pass no information to them; we hold none to pass.

Children

Babypercentiles is written for parents and carers, not for children, and we do not knowingly collect information from anyone. Because the site holds no personal data at all, it holds none about children either, which is the point of building it this way.

Changes to this policy

If our data practices change, we will update this page and move the effective date above. We start from collecting no personal data and never receiving your child's measurements, so any change would only ever be described here in the same plain terms.

Contact

For privacy questions or anything else, reach the publisher through the Urban Algorithm contact page. Babypercentiles is a project of Urban Algorithm LLC.