Integrated Information Theory

Integrated information theory (IIT) is a theoretical framework for understanding consciousness developed by Dr. Giulio Tononi and collaborators at the Center for Sleep and Consciousness at the University of Wisconsin–Madison.



PyPhi is a Python library for calculating integrated information (denoted Φ) and its associated quantities and structures. It is open-source and available on GitHub, and can be installed on the command line with the Python package manager via pip install pyphi.

The figures in the IIT 3.0 paper are illustrated with PyPhi as an IPython notebook and in the online documentation. This section is meant to serve as a companion to the paper, and readers are encouraged to follow along and analyze the systems shown in the figures, hopefully becoming more familiar with both the theory and the software in the process.

Please consult the the project's README for more information.

Visual Interface

There is a visual interface to this code available on this website via the “Calculate Φ” tab above.


Online documentation is available. There are some examples that demonstrate how to create a network and measure its Φ, and comprehensive documentation of the API.

Additionally, the source code itself is commented. Those familiar with Python are encouraged to read the code to better understand the details of the calculation.


For discussion about the software or integrated information theory in general, you can join the PyPhi users group.

For technical issues with PyPhi or feature requests, please use the GitHub issues page.