Utilize Stockfish to analyze chess games on your Windows PC
Stockfish is a free chess engine. It's one of the strongest engines available and is widely used for analyzing chess games. Being an engine means that it doesn't have its own user interface, i.e., it won't draw the chessboard and such. To interact with Stockfish, you'll need to plug it into a compatible chess app as described below.
Get started: First steps
- Download and unpack Stockfish.
- Download and install a UCI-compatible app such as Chess 2026.
- Point the app to the Stockfish executable.
- Try if it works. For example, if you have assigned Stockfish to Coach in Chess 2026, have a move suggested — use the Coach menu or press Alt+1.
Troubleshooting
Optimize performance: Engine options
In order for Stockfish to fully use the power of your PC, you'll need to do a few more settings. Here is how:
- Open UCI engine settings in your app.
- In the Engine options section, enter the following:
Hash = a quarter your PC's RAM in MB
Threads = a half of your PC's logical processors
You can find the data on your PC's hardware in the Windows Task Manager (Performance tab).
In Chess 2026, these values are already calculated for you, just copy the two lines from the Example in the bottom right corner of the UCI engine dialog. Your Engine options may look similar to this:
Hash = 4000
Threads = 8
Learn more: Settings explained
The Hash value sets the amount of RAM memory allocated for Stockfish when it's running. The Threads value sets how many computations Stockfish runs in parallel. Stockfish defaults are very conservative:
Hash = 16
Threads = 1
These values need to be ramped up to make use of installed memory chips and the CPU. That being said, it's not a good idea to assign all resources to Stockfish. There should also be a breathing room for the operating system and other apps. Too high values will overload the machine and Stockfish itself will not perform optimally. The values recommended in the Optimize section will significantly improve Stockfish performance while leaving some resources available for other use and not overloading the system. Nonetheless, if you don't want to use your PC for other purposes while running Stockfish, there is a room to increase the values some more. These are reasonable upper bounds:
Hash = three quarters your PC's RAM in MB
Threads = all of your PC's logical processors minus one
There will be diminishing returns when approaching these values and a likely decrease in performance when going beyond them.
Stockfish documentation
Optimal settings — the official recommendation, in line with the upper bounds above
List of options — the full list of options that Stockfish supports
UCI dialog in Filip Höfer Chess
