Cookie Policy

1. Overview

Short version: TrueElo uses no advertising or cross-site tracking cookies. Sign-in uses Lichess OAuth with tokens kept in your browser's local storage, your saved chess work is kept privately under your own account, and our analytics may set first-party identifiers only.

2. What Are Cookies?

Cookies are small text files stored on your device by websites you visit. They are commonly used for:

• Tracking users across websites (advertising)
• Session management (login state)
• Remembering preferences
• Analytics and usage metrics

Cookies are automatically sent to the server with every request, which enables tracking and identification.

3. Why TrueElo Minimizes Cookies

TrueElo is designed to minimize cookie usage:

• Token-based authentication: Lichess OAuth tokens live in local storage, not cookies
• No ad network: We don't serve third-party ads or use analytics for cross-site ad targeting; we do measure which campaigns bring visitors to TrueElo
• No cross-site tracking: No third-party tracking or profiling cookies
• Your data is yours: Your repertoire, drill progress, and settings are kept under your own account, not readable by other players

4. Storage Instead of Cookies

TrueElo uses browser storage for sign-in, preferences, caches, and analytics identifiers:

• We do not use these identifiers for advertising or cross-site tracking
• Your sign-in token is never stored on our servers — each time it is sent, it is used for that request and dropped
• Your saved lines, drill progress, Leaks reports and settings are kept under your account, not readable by other players, and cached on each device you sign in to
• You can export or delete your saved account data. Deleting saved data does not delete historical analytics or recordings.

5. What We Store, and Where

Kept in this browser, and never stored on our servers:

• Sign-in token: Your Lichess session, removed when you sign out. TrueElo receives it each time you open the app, to confirm the account is yours, and with each Leaks report of a Lichess account you ask for, to fetch its games. It is used for that request and never written down on our side.
• Game statistics: How often each move won, drew and lost in public games, fetched directly from Lichess and cached against the position on this device
• Engine results: The analysis your browser computed in the analyzer and drills, cached so it does not have to compute it twice
• Leaks report in progress: Which report this browser is following while TrueElo's servers read it, so coming back shows it; removed once this browser sees it end
• Earlier reports being removed: A marker that this browser asked for the reports made before Leaks was rebuilt to be removed, so an interrupted removal finishes on your next visit; cleared when it is done
• Drill streak: Your run of consecutive days. This one is per-device and does not follow your account
• Theme: A copy of your light or dark choice, so the page can paint correctly before you sign in. The choice itself is a preference and follows your account (section 6).

Kept under your account, and cached on each device you sign in to:

• Settings: Your preferences
• Saved lines and drill progress: The work you choose to save
• Leaks reports and practice: Your reports and the positions they gave you to practise, which TrueElo's servers write when they read your games

Kept under your account on TrueElo's servers only, never sent to your devices: the engine's evaluations of your positions and the Lichess games a report read, without the opponents' names.

See our Privacy Policy for more information.

6. Authentication and Analytics Storage

Signing in uses Lichess sign-in (OAuth 2 with Proof Key for Code Exchange, PKCE). The resulting access token is stored in your browser's local storage — not in a cookie — and is removed when you sign out. Lichess itself may set cookies on lichess.org during the sign-in redirect, governed by the Lichess privacy policy.

PostHog stores first-party analytics identifiers in local storage to connect page visits, including visits without an interaction, and duration, campaign attribution, product events, performance measurements, and session recordings. Recordings begin after interaction. Signing in links earlier browser activity to your TrueElo account ID, which does not contain your chess username or email. The Privacy Policy explains what recordings contain and how to exclude this browser from usage events, performance measurements, and recordings.

7. Third-Party Services

TrueElo connects to third-party services for functionality:

• Lichess for authentication (OAuth2) and game statistics
• Firebase for your own saved data, sign-in, and account access
• PostHog for product analytics, session recordings, and error diagnostics
• Formspree for the contact form
• Lemon Squeezy for checkout and for managing a Plus plan. Those pages open in a new tab and set Lemon Squeezy's own cookies under its policy.

We do not embed advertising networks or social media widgets that use tracking cookies.

8. Clearing This Browser

You can clear TrueElo's browser storage at any time:

Note: This clears this browser only. Your saved lines, drill progress, Leaks reports and settings are kept under your account, so signing in again brings them back. Clearing site storage also clears this browser's analytics exclusion preference; it does not delete previously collected analytics. To delete saved account content, use “Delete everything” in Settings.

9. Analytics Choice

Authentication storage lets you access your account. Analytics storage connects usage events and recordings. These serve different purposes. Use the browser exclusion control on our Privacy Policy page to stop analytics, recordings, and error reporting in this browser.

10. What You Can Control

We do not use advertising or cross-site tracking cookies. To exclude this browser from analytics, session recordings, and error reporting, use the “Analytics in this browser” switch on the Privacy Policy page. Exclusion stops future collection in this browser; it does not delete events already sent to PostHog.

11. Contact

For questions about this Cookie Policy, use the contact us.