Last updated 3 September 2026

Terms of use

Using Checkmate Central means agreeing to what follows. It is short, and none of it is a surprise.

  • Free, as isAn engine's opinion, with no warranty.
  • Games that are overNever use it during a game you are playing.
  • Your gamesAnalyse your own games, or public ones.
  • Be politeDo not overload the service or the sites it reads.

What this is

Checkmate Central is a free tool for reviewing chess games. It reads games you import from chess.com or lichess, or paste as PGN, analyses them with the Stockfish engine running in your browser, and reports what each move cost. There is no account, no subscription, and no server holding your games.

It is provided as it is

The tool comes with no warranty of any kind. In particular:

  • Grades and evaluations come from a search to a limited depth. They are an engine's opinion, not a verdict, and a deeper search sometimes disagrees.
  • Move classifications are thresholds applied to that opinion. A move on the edge of two grades could reasonably be called either.
  • Nothing here promises the site will be available, correct, or free of faults.
  • Analysis is a learning aid. It is not a ruling on a game, a player, or a position.

Analysis is for games that are over

This is the one rule worth stating on its own. Do not use this, or any engine, during a game you are playing. Engine assistance in a live game is cheating. It is against the rules of every serious chess site, it is unfair to the person across the board, and it will get your account closed.

The tool is built for the position you have already lost, not the one you are still in.

What is asked of you

  • Analyse games you have a right to analyse — your own, or games that are public.
  • Respect the terms of the site you import from. Both APIs are used politely: one request at a time, never in parallel — a month of chess.com games per request, and a single request to lichess.
  • Do not use the tool to break the rules of a site you play on.
  • Do not attempt to overwhelm, disrupt, or misuse the service.

Other people's things

Game data imported from chess.com or lichess belongs to the players and to those sites, and their terms govern it. Checkmate Central is not affiliated with, endorsed by, or connected to either.

The engine is Stockfish, free software under the GNU General Public License v3, loaded here as a separate WebAssembly worker and unmodified. Serving it to you is distributing it, so the licence travels with it: a copy sits beside the engine files at /stockfish/18.0.8/Copying.txt, and the corresponding source is the WebAssembly build of Stockfish itself. The board and move handling use open-source libraries under their own licences.

The sound a piece makes when it lands is cut from “Chess pieces” by simone_ds, used under the Pixabay Content License, which asks for no credit — this is here because a recording of somebody's hands should be said out loud. The rest of the site — its design, copy, code and the other sounds, which are drawn with oscillators rather than recorded — belongs to its author.

Liability

To the extent the law allows, the author of this tool is not liable for any loss arising from using it. That includes games lost after following its advice, decisions taken on an incorrect evaluation, and any time the site is unavailable. It is a free tool for looking at chess games; treat it as one.

Changes

These terms may change. The date at the top of this page says when they last did, and continuing to use the tool after a change means accepting the current version.