About

Chess Engine Online is a free analysis board and a set of written explanations of what a chess engine is telling you. It is run by Allegro Digital, which also publishes Chess Engine for Stockfish on the App Store and Google Play.

Which engine

Analysis comes from Stockfish, the open-source engine developed by the Stockfish community and distributed under the GNU General Public License v3. This site is not affiliated with the Stockfish project and does not speak for it.

Searches from this site run to about depth 16. The engine stops on depth or on time, whichever arrives first, so a sharp position may be searched slightly less deeply than a quiet one. That is why pages here describe a search as about a depth rather than quoting a number as a guarantee.

What happens to your positions

When you press analyse, your browser sends the FEN to the analysis service and receives a move back. There is no account, nothing is stored against you, and the site itself has no server — it is a set of static files, so it could not collect anything if it wanted to.

Why the app exists as well

A web page can analyse a position you can already describe. It cannot look at the board on your table. The app reads a position from a photograph or a screenshot, keeps your saved boards, and analyses without a connection. That is the difference, and it is the only reason the site mentions it.

Corrections

If something here is wrong, it is worth fixing. The chess content is written to be specific enough to be checkable, which also means specific enough to be wrong in a way somebody can point at.