Legal
Cookie Policy
Effective October 24, 2026
CETPrep uses essential authentication cookies and browser storage for preferences and work in progress. Optional first-party usage measurement stays off unless you allow it. It uses a random browser ID, not advertising cookies or a third-party analytics SDK. Where measurement is enabled, you can allow or decline it and change your choice at the bottom of the page.
Cookies we set
The authentication cookie is necessary to keep you signed in.
- sb-<project>-auth-token
- Keeps you signed in and lets the server verify your session. Set by Supabase, CETPrep's authentication provider. Without it you cannot stay logged in.
- Lasts: Until you sign out or the session expires
Browser storage we use
Most of these values stay on your device to remember preferences and protect work in progress. The exception is the optional measurement browser ID: if you allow measurement, it is sent to CETPrep with a day and a broad link source such as Discord. When signed in, visits are associated with your account to measure signup, first completed practice, and a return on a later day. No full URLs, raw IP addresses, names, emails, or answers are saved in visit records. Existing account and saved-practice records are also used for aggregate reports. Supabase stores the visit records, which only the operator can access.
- cetprep-measurement-v1
- Remembers your optional measurement choice for 90 days. Only when you allow measurement, it also stores a random browser ID to connect visits, signup, completed practice, and return visits. You can change your choice at the bottom of any page where measurement is enabled.
- Lasts: 90 days; expired choices are ignored
- cetprep-theme
- Remembers whether you chose light, dark, or system appearance.
- Lasts: Until cleared
- cetprep-sidebar-collapsed, cetprep-sidebar-collapsed-groups
- Remembers which sidebar sections you collapsed.
- Lasts: Until cleared
- cetprep-mock-session:<attempt>
- Holds your in-progress mock test answers so a refresh or a dropped connection does not lose the attempt.
- Lasts: Until the attempt is submitted
- cetprep:completed-topics:v1
- Tracks which practice topics you finished, so progress shows correctly before it syncs.
- Lasts: Until cleared
- cetprep-session-feedback-at
- Records when you were last shown a feedback prompt, so you are not asked repeatedly.
- Lasts: Until cleared
Storage set by others
- Video lessons.CETPrep embeds YouTube through its privacy-enhanced domain, so YouTube does not store playback cookies until you actually start a video. Once you press play, YouTube's own terms apply.
- Google Sign-In.On the login and signup pages only, CETPrep loads Google's sign-in script, which may read Google's own cookies to show your Google accounts. It is not loaded anywhere else in the app.
- Donations. Ko-fi is a separate website. If you follow a donate link, Ko-fi sets its own cookies under its own policy. CETPrep receives no cookie or payment data from it.
Controlling cookies
You can clear or block cookies and site data in your browser settings at any time. Blocking the authentication cookie will sign you out and prevent you from signing back in; clearing browser storage will reset preferences and can discard an unsubmitted mock test attempt. Declining measurement stops collection. Turning it off also asks CETPrep to delete visit records for the browser ID on this device; if removal fails, the page reports that and lets you retry. Clearing browser storage alone does not remove previously saved server records. Visit records older than 90 days are removed when collection next runs. Browser Do Not Track and Global Privacy Control signals prevent optional collection. These choices do not delete your account or learning progress; use the support form for account data requests.