Cookie Policy
Effective from: 19 October 2026
Cookies are small files that a website stores in your browser. localStorage and sessionStorage work in a similar way. In this policy we call all of these “cookies”.
Under the law (including the Irish ePrivacy rules, S.I. 336/2011), cookies that are necessary for the site to work may be set without consent. All others need your consent, and we ask for it in the banner.
1. Necessary (no consent needed)
Without them, sign-in, language, theme and saving progress in the interface do not work. They cannot be turned off in the site settings, only in the browser itself, and then part of the site will stop working.
| Name | Type | Purpose | Duration |
|---|---|---|---|
| __Secure-next-auth.session-token | cookie | Keeps you signed in | 30 days |
| __Host-next-auth.csrf-token | cookie | Protection against cross-site request forgery (CSRF) | Until you close the browser |
| __Secure-next-auth.callback-url | cookie | Returns you to the right page after sign-in | Until you close the browser |
| i18next | cookie | Your chosen interface language | 10 minutes |
| i18nextLng | localStorage | Your chosen interface language | Until you clear it |
| theme | localStorage | Light or dark theme | Until you clear it |
| clv_consent | localStorage | Your choice in the cookie banner | 12 months |
| clevrolab_xp and other interface keys | localStorage / sessionStorage | Interface state: XP in the header, an unfinished level test, filters, dismissed hints, shadowing settings | localStorage: until you clear it; sessionStorage: until you close the tab |
The site also registers a service worker so that it can be installed as an app. It does not cache or track anything.
2. Analytics (only with consent)
These cookies help us understand where people come from and how they use the site. We turn them on only if you clicked “Allow analytics”.
| Name | Type | Purpose | Duration |
|---|---|---|---|
| clv_attribution | sessionStorage | UTM tags and the site you came from. Saved to your profile when you sign up | Until you close the tab |
| ph_*_posthog | cookie and localStorage | PostHog product analytics. Currently turned off | Up to 1 year |
3. Statistics without cookies
Vercel Web Analytics counts page visits without storing anything in your browser and does not track you across sites. That is why it does not need consent. How we process this data is described in the Privacy Policy.
4. Third-party content
We do not embed video players, social media widgets, ads or tracking pixels. Thumbnails of YouTube videos in your dictionary are loaded from img.youtube.com, so Google sees your IP address. Links to YouTube, Telegram, TikTok and Instagram open third-party sites with their own cookies.
5. How to change your choice
You can change or withdraw your consent at any time: click “Cookie settings” at the bottom of the home page. You can also delete cookies and site data in your browser settings; the banner will then appear again.
Questions: clevrolab@gmail.com.