Privacy policy

In short

• There are no accounts and no adverts, Chess Explosion's own code sets no cookies, and nothing about you is sold.
• The site counts visits with Vercel Web Analytics and measures how fast its pages load with Vercel Speed Insights.
• The game runs in your browser, the computer opponent included, and keeps its settings there.
• The extension reads the board on lichess.org pages to draw it in 3D. Its own code sends nothing to me or to anyone else.

Who is responsible

Chess Explosion is made by one person, Michal Dobiezynski, who decides how the information below is used. The site and the game are hosted by Vercel.

Hosting

chessexplosion.com and the game at chessexplosion.com/play are served by Vercel. Like any web host, Vercel receives your IP address, your browser's details and the full address of each page and file you load, including anything after a question mark in it. Serving the site and keeping it safe needs this, which is the legitimate interest it rests on.

Vercel may handle this, and the figures described below, outside the UK, including in the United States. It takes part in the EU-US Data Privacy Framework and its UK Extension, and uses standard contractual clauses where the law asks for them; see Vercel's privacy notice.

Visits and loading speed

Every page of the site and the game loads Vercel Web Analytics and Vercel Speed Insights. Web Analytics uses no cookies. It records the page, the site you came from, your approximate location (country, region and city) and your browser, operating system and kind of device. It tells visitors apart by a code made from the request and replaced every day, so a visitor cannot be followed from one day to the next, or to other sites.

Speed Insights records how quickly pages load and respond, with the page, your connection speed, browser, device and country. Its measurements are not tied to you or to your IP address.

In the game, the page's address is cut down before it is counted: only which part you opened is sent (a game, a replay and where it came from, the World or a piece's spotlight), never the moves, positions or settings in the address. The live scenes on the home page are pages of the game, so each one that loads counts as a visit to it.

I use these numbers to run the site and to make it better; that is the legitimate interest they rest on, and you can object to it at any time (see Your rights below). Vercel explains how it keeps them in Web Analytics and privacy and Speed Insights and privacy.

Replaying a game

When you replay a game from a Lichess link, your browser asks Lichess for the game directly. Lichess receives the game's id with your IP address and browser details, under Lichess's own privacy policy. A pasted PGN is read in your browser and is not sent anywhere as it is.

To show a replay, the moves (and the starting position, when the game did not begin from the usual one) are put into the address of the game's page. That address reaches Vercel like any other, and it stays in your browser's history. Player names and the other details of a PGN are not included.

In your browser

The game remembers your settings (such as the side you play, the speed, the sound and the camera) and your best raid score in your browser's local storage, and your progress through the World in session storage, which is cleared when you close the tab. They never leave your browser, and clearing the site's data removes them.

Stockfish, the computer opponent, runs in your browser too: no position is sent to a server.

Chess Explosion's own code sets no cookies. If Vercel's security system ever checks your browser before letting it through, it keeps a challenge session in your browser for an hour.

How long it is kept

On the site's current plan, Vercel shows me request logs for an hour, and the visit and speed figures for a month or less. Vercel itself keeps information only as long as it needs to, by the criteria in its privacy notice; Chess Explosion stores none of it. What the game and the extension keep in your browser stays there until you clear it; if you use Chrome Sync, Chrome also copies the extension's settings to your Google account.

Chess Explosion for Lichess

The Chrome extension draws Lichess's board in 3D on the analysis board, in studies and on games you watch. It stays off puzzles, variants and games you are playing.

To do that, it reads from each lichess.org page the kind of page it is, the pieces on Lichess's board, the last move and any check, and which way the board faces. It uses this only to draw the board in your browser, and keeps no record of the positions or games it reads. Its own code sends nothing to me or to anyone else: it has no analytics.

On the analysis board and in studies, a move you make on the 3D board is played on Lichess's own board, as if you had made it there; what Lichess then does with it, such as saving it to a study, is up to Lichess. The extension never makes a move you did not make.

It keeps its settings (on or off, speed, sound and attack zoom) in Chrome's storage for extensions, which Chrome copies to your Google account if you use Chrome Sync, and a few display preferences, such as which side the last board was seen from, in its own storage in your browser.

It asks for three permissions: storage, for those settings; scripting, to play your moves on Lichess's analysis board; and access to lichess.org, the only site it works on. Its Piece spotlight and World buttons open chessexplosion.com in a new tab, where the rest of this policy applies.

The use of information received from Google APIs will adhere to the Chrome Web Store User Data Policy, including the Limited Use requirements.

Chess Explosion for Lichess is not made or endorsed by Lichess.

What Chess Explosion does not do

• No accounts and no sign-in.
• No selling or renting of information about you, and no sharing of it beyond what this page describes.
• No adverts, and no following you across other sites.
• No database of visitors.

Your rights

You have the right to object, at any time, to the hosting records and the visit and speed figures described above, which rest on my legitimate interests. To object, write to me as shown at the end of this page.

Under UK data protection law you can also ask what information I hold about you, and ask me to correct it, delete it or limit its use. Chess Explosion keeps no records that identify individual visitors, so there is usually nothing to give, correct or delete; Vercel and Lichess keep their own records under their own policies.

If you are unhappy with how your information is handled, you can complain to the Information Commissioner's Office.

Changes and questions

If any of this changes, this page will change with it, and so will its date. Questions are welcome: write to me on X or LinkedIn, linked at the foot of the page.