Privacy Policy

Last updated: October 19, 2026

This page describes what data is processed by the Chess.com Companion Chrome extension and its companion website, why, and who it may be shared with. It applies to all users of the extension, whether or not you use the Pro subscription.

Chess.com Companion reads public chess.com statistics directly from your browser and runs Stockfish analysis locally. Our server uses an anonymous installation identifier to check subscriptions and records free search and review usage timestamps to manage limits. Game moves and analysis results are not sent to our server. No data is sold to third parties.

1. Who is responsible for data processing

Chess.com Companion is published by WTZLabs. For any question about this policy or to exercise your rights, you can contact us at contact@wtzlabs.com.

2. What data is collected, and why

Data	Source	Purpose	Shared with
Anonymous technical identifier (deviceId)	Randomly generated by the extension and stored locally in your browser (`chrome.storage.local`)	Check subscription status and apply free search and game-review limits for this installation	Our license server: `api-chess.wtzlabs.com`
Free search and review usage timestamps	Recorded by the server when a free search or review is authorized	Enforce rolling limits of 3 player searches per 7 days and 3 game reviews per 24 hours	Our license server, linked to the anonymous deviceId; no searched usernames, game moves or analysis results are included
Game statistics (Elo, game history, openings, banned opponents)	chess.com public API	Display in the extension's side panel	No one. These requests go directly from your browser to `api.chess.com`, our server never has access to them
Email and payment information (only if you subscribe to Pro)	Stripe payment form	Subscription processing, billing	Stripe. We only receive a subscription confirmation linked to your deviceId, never your banking details

What the extension never does:

It never reads or stores your chess.com credentials or session: no login to an account is ever requested.
It doesn't send your moves or engine results to our server: Stockfish analysis, opening theory highlighting and opponent detection run locally in your browser.
It doesn't build an advertising profile and doesn't use your data for targeting purposes.
It doesn't track your browsing outside of chess.com pages.

3. Why the extension communicates with api-chess.wtzlabs.com

Pro unlocks advanced Search features and unlimited searches and game reviews. To check whether your installation has an active subscription, the extension sends its anonymous identifier to our license server (api-chess.wtzlabs.com), when the panel opens and periodically in the background (roughly every 12 hours). Before a free search or game review, the extension also requests quota authorization using that identifier. The server records the usage timestamp and returns the remaining quota or reset time. It does not receive searched usernames, game moves or Stockfish analysis results in these requests.

4. Sharing data with third parties

We do not sell or rent any data to third parties. A limited number of technical subprocessors are involved in running the service:

Stripe: processing payments and the Pro subscription.
Our hosting provider: hosts the license server (api-chess.wtzlabs.com).
chess.com: the statistics shown come from its public API, queried directly by your browser, with no intermediary on our part.

5. Retention period

Free search and review usage records older than 30 days are removed when the server starts. These records contain the anonymous installation identifier and usage timestamp.

The anonymous identifier and its associated license status are kept for as long as the Pro subscription is active, then for a reasonable period after cancellation for support purposes. You can request deletion of this data at any time by writing to contact@wtzlabs.com.

6. Your rights

Under the GDPR, you have the right to access, rectify, erase, restrict, and object to the processing of your data, as well as the right to data portability. To exercise these rights, contact us at contact@wtzlabs.com. You also have the right to lodge a complaint with the competent data protection authority.

7. Permissions requested by the extension

Each Chrome permission requested by the extension has a precise, limited use:

Permission	Use
`storage`	Save your preferences and anonymous license identifier locally.
`activeTab`	Read the usernames shown on the active chess.com tab to detect the current game.
`sidePanel`	Display the extension's interface in the Chrome side panel.
`alarms`	Periodically recheck the Pro subscription status in the background.
Host access: `api.chess.com`	Retrieve players' public statistics.
Host access: `www.chess.com`	Detect the current game and display opening theory highlighting on the board.
Host access: `api-chess.wtzlabs.com`	Check the Pro subscription status.

8. Cookies

The extension does not use any tracking cookies. This static website does not use advertising cookies or third-party analytics trackers.

9. Security

All communications between the extension and our servers use HTTPS. No banking information ever passes through the extension or our server: this data is handled exclusively by Stripe.

10. Changes to this policy

This policy may be updated to reflect changes to the extension or legal obligations. The last-updated date at the top of this page reflects the version in effect. In the event of a significant change, a notice will be posted on this site.

11. Contact

For any question about this privacy policy or your personal data, contact us at contact@wtzlabs.com.