Cookie Policy
Last updated: 16 October 2026
The small pieces of data Prezi Prep stores in your browser, what each one is for, and how long it lasts.
1. What are cookies and browser storage?
A cookie is a small text file a website places in your browser so that it can recognise you on the next request — for example, to keep you signed in. Browser storage ("local storage") is a similar space the browser keeps for a website, which is not sent along with requests.
We use both, sparingly, and only for things the Services need in order to work or to remember a choice you made. We do not use cookies for advertising, and we do not track you across other websites.
2. What we use them for
- Strictly necessary — keeping you signed in, and protecting the sign-in flow. The Services cannot work without these.
- Preferences — remembering your language and theme, so you do not have to pick them again.
- Continuity — keeping a copy of a test you are in the middle of on the device, so that a dropped connection or a closed app does not lose your answers.
3. Cookies we set
| Name | Purpose | Type | Lifetime |
|---|---|---|---|
| prezi_session | Keeps you signed in. Signed by our server and marked HttpOnly and Secure, so scripts and other websites cannot read it. | Strictly necessary | 30 days, renewed while you keep using the Services |
| prezi_oidc_nonce | A one-time value that protects the sign-in flow against forged requests. | Strictly necessary | 10 minutes, or until sign-in completes |
| prezi_locale | Remembers the language you chose. | Preference | 365 days |
All three carry the "Secure" flag, so they travel only over encrypted connections, and "SameSite=None", because Telegram opens the app inside a frame on some platforms. Every request that changes data is checked against the page that sent it, which is what makes that setting safe.
4. Browser storage we use
| Key | Purpose | Lifetime |
|---|---|---|
| heroui-theme | Your light or dark theme. | Until you clear browser data |
| prezi.attempt.* | A copy of a test in progress — the questions and the answers you have chosen — so that it survives a lost connection or a closed app. | Removed 7 days after last use, or when browser data is cleared |
5. Third-party cookies
- Telegram. The sign-in button and the Mini App load scripts from Telegram, and Telegram may set cookies on its own domains during sign-in. These are governed by Telegram's Privacy Policy, not by us.
- Analytics. Vercel Web Analytics counts page views in aggregate. It sets no cookies and does not identify visitors across sites.
No other third party sets cookies through the Services. There are no advertising networks.
6. How to control cookies
You can delete or block cookies and local storage in your browser's settings; every browser explains how in its help pages. If you block the strictly necessary cookies, you will not be able to sign in. Clearing storage signs you out, resets your theme, and discards the saved copy of any test in progress — the answers already sent to our server are kept.
Inside Telegram, the Mini App uses Telegram's built-in browser; its data is cleared from Telegram's own settings.
7. Changes to this policy
If we add or change a cookie, this page and the date at its top are updated. Material changes are announced in the app.
8. Contact
Questions? Write to us through the Telegram bot @PreziPrepBot, or use the contact page.