Privacy
Your data stays with you.
Last updated .
Height Lens is built so that you don’t have to trust us with anything. There are no accounts, and the comparison tool runs entirely in your browser. This policy says exactly what that means, including the parts that are not perfectly private.
The short version
- No account, no sign-up, no email required to use anything on the site.
- No analytics, no cookies, no advertising and no third-party tracking scripts.
- Your photos never leave your device. They are resized and drawn in your browser.
- Your chart is saved on your device, not on a server, and you can delete it at any time.
- We hold no personal data about you unless you choose to email us.
What is stored on your device
The tool keeps a little state in your browser’s local storage so the site is still useful when you come back. It is stored on your computer or phone, it is readable only by this site, and it is never transmitted to us.
- Your current chart — the names, heights, units, colours and order of everyone on it, plus the country you chose for percentiles.
- Your theme preference (light or dark).
- Images you have added, resized in the browser first. If they are too large for the storage quota, the chart is saved without them rather than failing.
To delete all of it: use Clear All in the tool, or clear this site’s data in your browser settings. There is nothing on our side to request deletion of, because there is nothing on our side.
One related detail: the tool guesses a default country for percentiles from your browser’s language setting. That check happens in your browser and the result goes nowhere.
What we do not do
There is no Google Analytics or equivalent, no advertising or affiliate network, no social media pixels, no session recording, no fingerprinting, and no cookies — we set none at all, which is why you have never seen a cookie banner here. Web fonts are served from this domain rather than fetched from a third party, so loading a page does not announce your visit to anyone else. The only third-party content on the site is links you choose to click.
What reaches our host
The site is static files served by Cloudflare Pages. Like any web server, it records standard request information — your IP address, the page requested, a timestamp, your browser’s user-agent string and referring page — which is used to deliver the site and to protect it from abuse. We do not combine those logs into profiles, do not sell or share them, and do not use them to identify you. Cloudflare processes this as our hosting provider under its own privacy terms.
Share links
When you share a comparison, the names and heights on the chart are encoded into the link itself rather than saved to a database. Two things follow from that. Anyone who has the link can see those names and heights, and because they live in the URL they also appear in the host’s request logs and in the browser history of whoever opens it. So avoid putting anything private in a name you intend to share. Images are never included in a link — a recipient sees a plain block in place of your photo.
If you email us
Emailing [email protected] means we have your address and whatever you wrote, held in our mailbox so we can reply and keep track of corrections. We don’t add you to a mailing list — there isn’t one — and we don’t pass your message to anyone else. Ask us to delete a thread and we will.
Children
Height Lens is for a general audience and collects nothing from anyone, children included. You can put a child’s height on a chart, and like every other entry it stays in your browser. We knowingly collect no personal information from children because we collect none from anybody. Percentiles are deliberately not shown for children: growth is assessed against age-specific charts, which is a different calculation — see the methodology.
Your rights
Privacy law — the GDPR, the UK GDPR, the CCPA and India’s DPDP Act among others — gives you rights to access, correct, delete and port your personal data, and to object to its processing. We have designed the site so that those rights have almost nothing to attach to: there is no account, no profile, no tracking identifier and no server-side copy of your charts. Your local data you can delete yourself in one click. If you have emailed us and want that correspondence corrected or erased, ask and it will be. We never sell personal information, and there is nothing here to opt out of.
Links to other sites
We link out to the studies, record books and publications behind our figures. Once you follow a link you are on someone else’s site, under their privacy policy, not this one.
Changes to this policy
If what we store ever changes, this page changes with it and the date at the top moves. Since there is no mailing list to notify, that date is the record of when a change took effect. Material changes to how the tool handles your data will be described here plainly rather than buried in a redefinition.
Contact
Questions about privacy, or something here that is not clear? Contact us or email [email protected]. Our terms and conditions cover the rest of using the site.