Security

The safest calculator is the one that never sees your data. Here is how that is achieved.

Fully static architecture

This site is a set of static HTML, CSS, and JavaScript files. There is no backend, no server-side code, and no database. Nothing you type is processed, stored, or logged by a server — the pages themselves contain all the calculation logic.

Data stays on device

All calculations run in your browser. Your inputs never leave your device, so there is no data in transit to intercept and no data at rest to leak. The only thing ever written to disk is your theme preference (the ascc-theme key in local storage).

HTTPS everywhere

The site is served exclusively over HTTPS with modern TLS. Canonical URLs, redirects, and the service worker scope all use https://ageandsleepcalculator.dpdns.org. Mixed content is impossible by construction, because the pages make no third-party requests at all.

Service worker is same-origin only

The service worker that powers offline use is registered from the site's own origin and only intercepts same-origin requests. It never contacts another domain and never sees cross-origin traffic.

No third-party scripts or dependencies

The site loads no third-party scripts, libraries, CDNs, fonts, or embeds. That means a smaller attack surface and no supply-chain risk from external packages. What you see is exactly what we wrote.

Reporting a vulnerability

Found something that looks wrong? Email minitoolszz@gmail.com with the subject "Security Report". Please include the page URL, your browser and version, and a step-by-step description. We treat reports confidentially and aim to respond within a few business days.

More

For the full picture of how the site behaves, read the Privacy Policy and the Terms of Use.