Stockfish 19.0 is a free, strong UCI chess engine for Windows, released on September 5, 2026. The installer is 77.7 MB and comes straight from the official server at github.com, since we do not store it. Its package ID is Stockfish.Stockfish.
Who a UCI engine suits
Stockfish fits chess players who already use, or want to use, a chess interface that speaks the UCI protocol. The listing carries the tags chess and uci, which tells you it is built to plug into other software rather than to stand alone as a polished game.
The developer is Stockfish, and the project site is stockfishchess.org.
What the engine does in practice
The store description is short: a free and strong chess engine using UCI. Analysis modes, rating levels and a built-in board are not part of that description.
Cost, licence and download size
Stockfish is free and released under GPL-3.0. The 77.7 MB download is the only real cost to weigh.
Stockfish pros and cons
Pros
- Free to download
- GPL-3.0 licence
- Uses the UCI protocol, so it works with compatible chess software
- Version 19.0 released September 5, 2026
- Download served from github.com
Cons
- Large 77.7 MB download
- Needs a separate chess interface, since it uses the UCI protocol
- The 77.7 MB size is large for a single engine
Is Stockfish safe?
Stockfish is released under the GPL-3.0 licence by the Stockfish project, which keeps its home at stockfishchess.org. Version 19.0 is a 77.7 MB download. No scan results came with the listing, so it is sensible to run your own antivirus check on the installer before opening it.
How to install Stockfish
- Press the download button to get the official file.
- Run the installer you saved and confirm the Windows security prompt if the publisher matches.
- Follow the setup steps, then start Stockfish from the Start menu.
