Privacy
Last updated: October 2026
Where your games are analyzed
Chess analysis runs on your device by default. Your PGN games, the positions you set up, engine evaluations, move classifications and your settings are processed on your own device — in the browser on the web, on the phone in the Android app — and are not transmitted, uploaded or shared. There are two exceptions, both described below: Cloud Analysis, and fetching a game from a lichess or chess.com link.
Cloud Analysis (optional)
Cloud Analysis is an optional feature available to some accounts. It is off unless you turn it on under Settings → Engine, and you are asked to confirm before it is used for the first time.
While it is on, the board positions of the game you are analyzing are sent to our analysis server, hosted on Google Cloud, which runs the chess engine and sends the evaluations back. What leaves your device is the list of board positions and the strength setting you chose. The PGN file itself is not sent, so player names, event details, dates, results and any comments in the game stay on your device.
Requests carry your account identifier so that the analysis time can be counted against your tier or credit balance. That usage record — how much engine time an account used, and when — is all the server keeps. The positions themselves are not stored once the analysis finishes and are not retained, logged or linked to your account.
You can switch back to on-device analysis at any time, and the application switches back on its own if the server cannot be reached.
Fetching games from lichess and chess.com
When you share or paste a link to a game on lichess.org or chess.com and tap "Fetch Game", the application downloads that game directly from the site the link points to. Nothing is fetched until you tap the button. The request carries the game's identifier, your IP address and a user agent naming the application; for chess.com it also carries the player's public username and the month the game was played, which are needed to find the game in that player's public archive.
No account identifier is sent, and nothing from your own games. Those sites handle the request under their own privacy policies.
Opening links
The game screen links to this website's pages about the opening being played. To know which openings have a page, the application downloads a list from this website about once a week. That request is for one fixed file: it carries your IP address and nothing about your games — the opening on screen is recognised on your device. A page is only opened when you tap a link.
Accounts and what they store
To provide accounts the application uses Google Firebase (Firebase Authentication and Cloud Firestore). When you first open the application you are assigned an anonymous account identifier, which is created and stored on Google's servers. If you choose to sign in with Google, the application additionally collects and stores your Google account email address and display name.
This information is used solely to identify your account, to remember whether you are registered, and to determine which features are available to you. It is stored and processed by Google acting as our service provider, and Google's handling of it is governed by Google's Privacy Policy. No chess games, moves or analysis are ever linked to your account, and none are transmitted off your device except as described above for Cloud Analysis.
You may use the application as a guest without signing in.
Deleting your account
If you have signed in, you can delete your account from inside the application: Settings → Account → "Delete account". This permanently removes your account record — including your email address and display name — from Firebase Authentication and Cloud Firestore.
Deletion cannot be undone, and any ad-free or other tier entitlement attached to the account is lost with it. Because the application continues to work without a sign-in, a new anonymous account identifier is assigned to you afterwards.
If you cannot access the application, you can request deletion here instead.
Chess games, moves, analysis and settings are held only on your device and are not affected by account deletion; you can remove those by clearing the application's data or uninstalling it.
If you have used Cloud Analysis, in-app deletion also removes the usage record described above. That step needs our analysis server, so if it could not be reached at the time the record may remain; email us at the address below and we will delete it.
Advertising on this website
The pages of this website may display advertising served by Google AdSense. Google and its partners may use cookies and similar browser storage to serve and measure those advertisements; this is governed by Google's Privacy Policy. Where required by law, including in the EEA and the United Kingdom, Google presents a consent dialog before personalised advertising is served.
No advertising is shown in the Android or iOS applications, and no chess games, moves or analysis are shared with advertisers.
Hosting
This website is served by Google Firebase Hosting, which processes standard request data such as IP address and user agent in order to deliver the pages.
Contact
Questions about privacy or data handling: mostlyhumanquiteoften@gmail.com.
Chess Analyzer is published by playcat.