Privacy
Is a period tracker safe for your data?
A period tracker holds very personal information. Here's exactly where ours keeps it, and where it doesn't.
Whether a period tracker is safe mostly depends on who else can see what you enter. With Period Tracker Free, the only people who can see it are people with access to your browser.
How it works
Period Tracker Free is a static website. Your browser downloads the page once, and every calculation happens on your phone or computer after that. There's no account system, no database, and no server code that could receive your dates, even by mistake.
Where your data lives
By default: this tab only
The date and lengths you enter are kept in your browser's session storage. They survive a page refresh and are removed when you close the tab or browser.
The storage key is ptf_calc. Nothing is written to local storage, so nothing outlives the tab, and nothing is synced anywhere.
Deleting it
Close the tab. Clearing your browser's site data does the same. If you print the page, that copy is on your device only; look after it as you would any health record.
What we don't do
- No accounts, logins or email collection.
- No cookies.
- No analytics, advertising pixels or third-party scripts.
- No contact form, so there's nowhere to send health details by accident.
Like every website, our host sees standard technical information (such as your IP address and which page you asked for) when your browser downloads the site. That never includes anything you enter in the tracker. Theprivacy policy has the formal version.