Privacy and data

No generalities. Below is exactly what the app saves, where it keeps it, and what leaves your device.

In short: Your games, lesson progress and analysis results remain in your browser's memory and we do not send them anywhere. Only two things go out, and both require your action: username when importing from Lichess, and visit statistics if you agree to them. There are no accounts, logins, or data sales.

Who is responsible for this website

The data administrator is the owner of the website szachmaty.pl. Contact: mail@szachmaty.pl. In matters regarding data, errors or deletion of anything, write to this address.

What we save in your browser

The application uses the browser's local memory (localStorage). The data does not go to any server and is only available on this device and in this browser.

• Klucz szachy.v1: settings (theme, chessboard appearance, sound), history of played and imported games along with analysis results, progress in lessons and tactical training, balance of ranking games and local measurement events (maximum 200 entries, containing only the name of the event, timestamp, theme ID and number of solved tasks).
• Klucz szachy.consent.v1: Your decision on visit statistics and the date it was made.

We keep the data until you delete it. They have no expiration date because it is your own copy, not our collection.

Cache and offline mode

The application works offline, so it saves its files in the browser cache (Cache Storage), in storages szachy-shell i szachy-engine. We only store our own application files there: HTML, styles, scripts, fonts and the chess engine. We do not save answers from external websites or your games there.

The chess engine counts for you

Stockfish runs as WebAssembly inside your browser. The game you paste for analysis, position on the board and calculation results they are not sent anywhere. The analysis works even when the Internet is disconnected, as long as the engine has been previously downloaded.

Import z Lichess

If you enter your own Lichess username and click "Search", your browser connects directly to lichess.org and sends this username. Nothing else. We download up to the last 20 public batches of this account. This is the only request to an external service that the application makes without any connection to statistics. The rules of processing on the part of Lichess are specified in the policy of this website.

Visit statistics (only with consent)

We want to know how many people use the site and which parts are used. Google Analytics 4 is used for this, but it boots only if you click "I agree" in the consent bar. Until then, no Google script is loaded and no data leaves your browser.

• The recipient of the data is Google Ireland Limited and Google LLC.
• Cookies are set to recognize a repeat visit.
• The IP address is shortened (function anonymize_ip).
• We do not transmit your games, positions, usernames or analysis content to Google.
• The basis for processing is your consent, which you can withdraw at any time.

How to withdraw consent: Click "Privacy Settings" in the footer of any page and the bar will reappear. You can also delete website data in your browser settings.

Server logs

The website is hosted on a regular web server which, like any server, can save technical access logs: IP address, request date, website address and browser type. We do not use these logs for profiling or combine them with data from the application. We do not claim that there are no such logs, because that would be untrue.

What we do NOT do

• There are no user accounts or logins.
• We do not sell or share data with third parties.
• We do not display ads or conduct remarketing.
• We do not send newsletters because we do not collect e-mail addresses.
• There is no payment, so we do not process your billing information.

Your data, your control

Because we keep everything local, you control it directly, without writing to us and without waiting:

• View and copy: Settings in the application, "Export data" button. You get a complete JSON file.
• Przeniesienie: You can import the same file in another browser or device.
• Deletion: Settings, "Delete all local data". Erases everything permanently and immediately.

If you still want to contact us regarding data, please write to mail@szachmaty.pl.

Beta version

The website is in the testing phase and is developing. When the scope of data changes, we will update this page with the date below.

Last updated: July 20, 2026.