Cookies
Cookies
Version: 2026-05-09
This document is a translation of the original Czech version. In the event of any discrepancy between language versions, the Czech version shall prevail.
This document describes what cookies and similar technologies the duelgo Platform (operated by duelgo s.r.o., IČO 23846356) uses and why.
1. What Cookies Are
Cookies are small text files that websites store in your browser. They serve to make the website remember your login, preferences and the state of your interaction (e.g. a game in progress). Without cookies, some functions could not be offered at all.
2. Why We Do Not Have a Cookie Banner
Many websites display a cookie banner on the first visit asking "do you agree to our cookies?". We do not display a banner, because:
- We use only technically necessary cookies, which do not require consent to function (Article 5(3) of the ePrivacy Directive 2002/58/EC).
- We do not use third-party tracking cookies (Google Analytics, Meta Pixel, Hotjar, advertising networks).
- For anonymous traffic statistics we use the cookieless tool Plausible Analytics, which sets no cookies and does not identify individual visitors across websites — it therefore does not require consent.
- We process the statistical traffic data necessary for the functioning of the Platform anonymously/in aggregate, or as a legitimate interest under GDPR.
If in the future we ever wished to add cookies requiring consent, we would of course display a banner before such a cookie is set.
3. List of Cookies Used
3.1 Necessary cookies (always active)
| Cookie | Domain | Duration | Purpose |
|---|---|---|---|
connect.sid |
duelgo.fun | Session (expires on closing the browser, server-side session up to 365 days) | User login to the administration, preserving state between requests |
playerCookie |
duelgo.fun | 12 months | Identification of an anonymous Player across Duelgos, preventing duplicate responses |
i18next |
duelgo.fun | 12 months | Remembering the chosen interface language (Czech/English) |
_csrf (if applied) |
duelgo.fun | Session | Protection against CSRF attacks |
3.2 Server-side storage (not classic cookies, but an associated technology)
| Key | Storage | Duration | Purpose |
|---|---|---|---|
game:dup:{quizId}:{contentId}:{identity} |
Redis | 24 hours | Prevention of duplicate submission of a response |
game:user-link:{sessionId} |
Redis | 24 hours | Mapping session → user after registration |
sess:{sessionId} |
PostgreSQL | 365 days | Session data |
3.3 Local storage (localStorage/sessionStorage)
| Key | Duration | Purpose |
|---|---|---|
duelgo:editor-state-{quizId} |
Persistent until cleared | Local backup of a Duelgo in progress (only in the admin editor) |
duelgo:onboarding-dismissed |
Persistent | Hiding the onboarding banner after it is closed |
duelgo:player-{quizId}:progress |
24 hours | Game progress for continuing after the page is refreshed |
4. Third-Party Cookies — None
The duelgo Platform uses no third-party cookies. For anonymous traffic statistics we use Plausible Analytics — a tool that is cookieless (it sets no cookies or other identifiers on your device) and processes data in aggregate, without tracking individuals across websites. The service is hosted in the EU. We therefore do not need a cookie banner. If in the future we add cookies requiring consent, we will update this document and display a cookie banner with a consent request before they are set.
5. How to Manage Cookies in Your Browser
Most browsers accept cookies automatically, but you can block or delete them in the browser settings:
- Chrome: Settings → Privacy and security → Cookies and other site data
- Firefox: Preferences → Privacy & Security → Cookies and Site Data
- Safari: Preferences → Privacy
- Edge: Settings → Cookies and site permissions
⚠️ If you block necessary cookies, the Platform will not function correctly (you will not be able to log in or play a duelgo).
6. Your Rights
Cookies contain technical identifiers that may be considered personal data under GDPR. Your rights towards the Operator are governed by the Privacy Policy, § 7.
7. Contact
Send questions about cookies to info@duelgo.fun.
8. Changes
We may update this document when the Platform's technologies change. We communicate material changes to registered Users by e-mail.