Privacy Policy
Covers blundermindchess.com, buildabotchess.com
and the Blundermind Android app.
Published by Kelpdog · Effective 3 August 2026
The short version
- There are no accounts. You never give us a name, email or password to play.
- There is no analytics and no third-party tracking of any kind.
- There is no database. We have nowhere to keep personal information, and we don't.
- We do not sell, rent or share your information. There is nothing to sell.
- The only thing you can send us is a feedback message, and only if you choose to write one.
What stays on your device
Your settings, your saved bots, your board and piece styles, and which tips you've dismissed are kept in your browser's local storage. The Maia neural network — about 44 MB — is cached on your device so the app works offline and doesn't re-download every time you play.
All of it stays on your device. We cannot read any of it. Clearing the site's data in your browser, or uninstalling the app, removes it permanently.
Playing against the computer
The chess engines run entirely on your device. If using Lichess database during openings, the position is submitted to Lichess (see below). Otherwise moves are not sent anywhere when you play a bot, and the app works with no network connection at all.
Playing another person online
A two-player game needs a server to pass moves between you. While a game is running we hold the room in memory only: the game code, whose turn it is, and the two connections.
- Moves and chat messages are relayed straight to your opponent and never written to disk.
- The room is deleted when both players leave. Abandoned rooms are cleared automatically.
- Nothing survives a server restart. There is no game history and no chat archive.
Chat is not moderated or reviewed, because it is not stored. Please treat anything you type as visible to the person you're playing. Likewise, two-player games are not moderated and there is no cheat detection.
The openings database
Opening statistics — both master games and games between players at your chosen rating — come from the Lichess opening explorer. Your app never contacts Lichess directly: our server makes every one of those requests on your behalf and passes the answer back. Only the chess position travels upstream; your IP address and identity are never shared with Lichess.
Feedback you send us
If you use the feedback box in the app, or the contact form at the bottom of this page, the message you type is delivered to us by Formspree, a third-party form service, and arrives as an email. We read it and reply if you've asked us to.
Nothing is attached to that message except what you write, so please don't include anything sensitive. If you type your email address so we can answer, we hold it only in that email thread. Formspree handles the message in transit under its own privacy policy. Sending feedback is entirely optional and nothing else in the app depends on it.
If you email us directly instead, the message goes straight to our mailbox and no third-party form service is involved — but your address comes with it, as it does with any email. We keep it only in that thread, and we never add it to any list.
IP addresses
To stop the openings lookup being abused, our server counts recent requests per IP address, held in memory for a short window and then discarded. It is not written to a database, not linked to anything about you, and not used for any other purpose.
Our host, Railway, may keep standard short-lived request logs as part of running the service, as any web host does. That is infrastructure operation and is governed by their privacy policy.
Counting downloads
The Maia neural network is a large file — about 44 MB — and how often it is actually downloaded is something we need to know to run the site within its hosting budget. Our server therefore keeps four running totals for that one file: how many times it was sent in full, abandoned part-way, requested in pieces, and skipped because the visitor already had it.
That is the entire record. It counts transfers of a file, not people: no address, no identifier, no timestamp and no history is attached to any of it, and there is no way to tell from those four numbers who downloaded anything or when. Nothing is written to disk, and the totals reset to zero every time the server restarts. They are visible to anyone at /api/model-stats — there is nothing in them worth hiding.
Children
These apps are suitable for all ages. Playing requires no account and collects no personal information from anyone, including children. The single exception is the optional feedback box described above, which contains only what the sender chooses to type — we ask that children not send us personal details, and we will delete any that arrive.
Your rights
Rights to access, correct or delete personal data all depend on us holding some. From playing, we hold none — that data lives on your device and is entirely under your control; clear your browser data or uninstall the app and it is gone. The one thing we may hold is a feedback message you chose to send us. Ask and we will delete it, and tell you what it said first if you'd like.
Changes
If this policy changes, the effective date above changes with it. Material changes to what the app does with data will be described here rather than quietly reworded.
Getting in touch
This policy was AI generated, and while I have tried to assure its accuracy, I would be more than a little shocked if it were ideal. Questions about this policy, about privacy generally, or about anything else on the site — email blundermindchess@gmail.com. That is the best route if you want to attach a screenshot or a PGN, or if you would like a reply you can keep track of. If you notice anything incomplete or incorrect on this policy, please let me know.
Or use the form below — the same one as the feedback box in the app. It reaches us without revealing your address unless you choose to add it.