Privacy policy

Version 1.0 · last updated: 25 October 2026

1. Who is responsible

Data controller: CF3 SRL. For any privacy request write to info@chesscoo.com.

ChessCoo needs no account or registration. We do not require your name, e-mail address or password; you may choose to include an e-mail address when sending a suggestion or comment.

2. What stays on your device

Camera. The video from your camera is processed in your browser and is never sent to our servers. The chessboard / crop collection feature to improve recognition is not yet available in this release.

Games, moves and settings. Preferences are saved automatically in this browser on each change and restored on your next visit; if they are unavailable or invalid, defaults are used. Recognition and game state stay on your device and are not sent to us. An exported PGN stays on your device. If you export a game as PGN, the file is created on your device.

Lichess. If you connect a Lichess account, the access token stays in your browser and communication goes directly between your browser and lichess.org, under Lichess’s own privacy policy.

3. What we may receive

Anonymous diagnostics (on by default, you can turn it off). To find bugs and understand feature usage, the app sends fixed error categories, the affected app module and code line, app version, browser and operating-system family, broad screen-size and resource ranges, interface language and technical usage counters. It sends no free-form exception messages, images, chess moves, names, e-mail addresses, tokens or browser identifier. Country may be inferred by our hosting infrastructure; the diagnostic report stores only a country code, not an IP address. Reports are not linked to one another by an identifier. You can disable future reports at any time in Settings → Privacy → Send anonymous diagnostics; pending reports are discarded. Server archives are retained for up to 90 days; hosted Google Cloud Logging currently retains diagnostic reports for 30 days. Separate technical request logs are described below. Legal basis: our legitimate interest in service reliability and improvement; you may object by switching diagnostics off.

Help improve recognition — coming soon. This control is disabled. This release does not collect, queue or upload square crops, images or game records for training. A consent saved in an earlier version does not enable uploads.

Suggestions and comments. If you use the contact form, we receive the type of message, its text, your e-mail address only if you choose to give it, and the interface language, app version and browser/operating-system family. We use this information to read, answer and improve ChessCoo; we do not store your IP address with the message. Legal basis: our legitimate interest in responding to messages, keeping the service reliable and improving it. Messages are kept for 12 months and then deleted; you can ask us to delete yours earlier. Please do not include sensitive information in the text.

Additional diagnostic device details. When diagnostics are enabled, reports also include screen width and height in CSS pixels, pixel ratio, device category (phone, tablet or computer), browser language, and the mobile model and operating-system version when the browser makes them available. Screen pixels estimated from the pixel ratio are not a guarantee of the display's physical resolution. We do not infer an unavailable phone model by fingerprinting. These fields are used only for troubleshooting and aggregate usage statistics; they do not include a persistent device identifier and follow the same diagnostic opt-out and retention period.

Technical data in server logs. Like every web server, ours processes your IP address and request details to deliver the pages and to protect against abuse. Technical logs are kept for up to 30 days. In the protected administrator area, we also use these existing logs to count successful app-page openings and estimate distinct visitors and countries. IP addresses are processed only on the server; country lookup uses an offline database, without sending them to an external lookup service. The panel receives only aggregate counts, never IP addresses or persistent visitor identifiers. Distinct network addresses are an approximation, not a count of identifiable people; shared networks and VPNs affect these estimates.

Phone as camera. When you pair a phone, the video goes directly from the phone to your PC (WebRTC). Our server only relays the short technical messages needed to connect the two devices, and a public Google STUN server (stun.l.google.com) may be used to find the network path; it sees the devices’ IP addresses but not the video. The pairing code can be used for the first connection for up to 30 minutes. After pairing, reconnection with the same code remains available for 12 hours from the last connection.

Read-aloud voices. Moves are spoken with the voices of your browser or operating system. If you choose a voice marked “online”, the text of the moves is sent to that provider’s speech service (for example Google or Microsoft) under its own policy. Voices not marked “online” work on your device.

Cookies and local storage. We use no advertising or marketing cookies and we do not sell data. The app uses local storage for preferences, locally kept games and a random technical pairing key sent only with PC-to-phone signaling requests. The reserved administrator area uses a secure, HttpOnly session cookie after Google sign-in; normal app users do not need an account. Older test addresses may also use a technical cookie for pairing. Pairing keys and session cookies are never included in diagnostic reports.

4. Where data is stored and who sees it

The public app is hosted on Google Cloud in Europe. Diagnostic reports are also written to Google Cloud Logging so they survive app-instance restarts. Local test installations keep a server archive. Feedback is handled by the controller and the configured hosting service. Only the controller and technical providers who help us run the service, under appropriate data-processing terms, can access personal data for the purposes described here. We do not currently use a payment provider.

5. Transfers outside the European Economic Area

Some services you may choose to use (Google’s STUN server, “online” voices, Lichess and some Firebase or Google Cloud services) may process data outside the European Economic Area. Where a transfer occurs, it is subject to the provider’s applicable transfer mechanism and safeguards, such as an adequacy decision or contractual safeguards where applicable. You can ask us for information about the safeguards relevant to your data at info@chesscoo.com.

6. How we protect data

The public website uses HTTPS to encrypt traffic in transit. Uploads are checked and size-limited, upload rates are limited per address to resist abuse, and received data is stored without names or e-mail addresses, except for the optional contact e-mail address you explicitly enter in a suggestion or comment. No system is perfectly secure; if a breach affects you we will notify you via the app.

7. Your rights

You may ask for access to, correction or deletion of your data, restriction or portability, and you may object to processing based on legitimate interest and withdraw consent at any time. For anonymous diagnostics that are not linked to your identity, we may be unable to locate an earlier report; in that case we will tell you so. If your request concerns a feedback message, include the e-mail address you entered (if any) and the approximate date of the message to help us find it. Write to info@chesscoo.com.

8. Children

ChessCoo is not specifically directed at children. A minor may use it only with the consent of a parent or legal guardian. A parent or legal guardian should review privacy settings. Diagnostic reports can be disabled in Settings.

9. Changes

If this policy changes in a significant way we will say so in the app and update the date above.