Get Nissy

Source code Windows executable
Latest version nissy-2.0.3.tar.gz (67Kb) nissy-2.0.3.exe (780Kb)

In this page you can find download links (see above), installation instructions and upgrade instructions for nissy. If instead you wish to clone the git repository, you can use git:

git clone

For a summary of changes and a list of older versions see below. Some versions (for example 1.0) are not available directly, but can be obtained from the git repository.


System requirements

A full installation of nissy requires about 3.1Gb of space, of which 2.3Gb are occupied by the huge pruning table for fast optimal solving, and running it requires the same amount of RAM. One can choose to never use this function and not to install the relative pruning table. There is an alternative (slower) optimal solving function that uses about 500Mb of RAM. When generating the pruning tables automatically (see the section Tables below), at least 5.3Gb or RAM are required.


Try downloading and executing in a terminal the file nissy.exe, then follow the instructions in the Tables section below for installing the pruning tables. If nissy.exe does not work, you can try following the UNIX instructions in WSL (Windows Subsystem for Linux) or in a similar environment.

UNIX (Linux, MacOS, *BSD...)

Download the source archive (.tar.gz). Extract it with your favorite archive program, for example with

tar -xvzf nissy-VERSION.tar.gz

Open a terminal in the directory just extracted. If you wish, edit the Makefile to match your local configuration (this is usually not necessary, but you may want to change the PREFIX variable to change the installation path) and run


followed by

make install

Then follow the instructions below to install the pruning tables.


Once you have installed nissy, run

nissy gen

to generate all the tables that Nissy will ever need. Running this command requires around 5.3Gb of RAM, and it can take some time (about 40 minutes on my fairly old but decent laptop, with 8 CPU threads).

Some unnecessary technical detail: by default this command is going to use at most 64 threads. If you want you can choose to use more threads (if your CPU is very powerful) or fewer threads (if you for example want to run this command in the background while you do other stuff) with the -t option, for example nissy gen -t 1.

Alternatively, you can download all the tables (1.7Gb) and copy them into the correct folder (see manual page, ENVIRONMENT section). On UNIX operating systems this folder is either .nissy/tables in the user's home directory or $XDG_DATA_HOME/nissy/tables if the XDG variable is configured. On Windows it is the same directory as the nissy.exe executable file.


If you already have nissy installed and you want to upgrade to a more recent version, you can simply repeat the installation process:

Between each version new table files might have been added, or old ones may be not used anymore. Nissy will deal with this automatically.

Version history

Nissy v2

Version Date Comment
2.0.3 2022-09-10 Fixed bug in scramble dr
2.0.2 2022-06-01 Improved table generation speed
2.0.1 2022-02-22 Bugfix release
2.0 2021-12-29 Rewritten from scratch; much faster optimal solver

Nissy v1

Nissy v1 was released in 2020. It was slow, full of bugs and the code was quite terrible. But in practice it got its job done most of the time.