Cookies & Local Storage

How CertPrepX uses local storage

CertPrepX uses your browser's localStorage and IndexedDB rather than traditional tracking cookies. Some of this storage is strictly necessary to run the app; the rest is optional analytics that stays off unless you turn it on. This page explains both and how to control them.

Strictly-necessary storage (always on)

These items are essential for the app to work and cannot be switched off:

• Sign-in session — a Firebase Authentication session token that keeps you securely logged in.
• Offline cache — a Firestore cache so your study data loads quickly and works across brief connection drops.
• Saved preferences — small settings such as your interface choices.
• Push messaging token — stored only if you enable push notifications, so we can deliver them to your device.

Optional analytics (off by default)

If you choose Accept on our cookie banner, we enable:

• Google Analytics (gtag) — measures aggregate usage of the app.
• PostHog — product analytics that helps us understand which features are used and where the experience can improve.

Both use IP anonymization. We do not use advertising cookies, we do not use analytics for advertising, and we do not sell your data.

Your choice — accept, decline, or change your mind

• Accept turns analytics on. Decline keeps them off — strictly-necessary storage still works.
• To reset your choice, clear this site's data in your browser; the banner will appear again on your next visit.

Learn more

For the full picture of what we collect and why, see our Privacy Policy. For the providers involved, see our Subprocessors list.