PYTHIA is documented in several ways, both online and in publications. A dedicated publication for PYTHIA 8.3 is in the making.

License information

PYTHIA 8 is licensed under the GNU General Public Licence version 2 or later. Please respect the MCnet Guidelines for Event Generator Authors and Users.

The program and the documentation is Copyright © 2021 Torbjörn Sjöstrand.


PYTHIA is the product of many years of work developing models and implementing them in an event generator. When you use PYTHIA for a publication, both the most recent PYTHIA manual (currently An introduction to PYTHIA 8.2) and the paper(s) introducing the physics model you are using, must be cited. Note that in some cases the used physics models are not created by, or only partially created by, the PYTHIA authors, underlining the importance of proper citations.

HTML manuals and Doxygen

Here you can find online versions of the PYTHIA manual and a Doxygen representation of the code, dating back to Pythia 8.051, which was the first version to have a such a manual. For earlier versions in the Pythia 8 series, you have to download the code and study the contained manual.

PYTHIA 8.3 series:

PYTHIA 8.2 series:

PYTHIA 8.1 series:

PYTHIA 8.0 series: