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All download options

The latest stable version is 3.2.8 Kafkaesque Koffka, released on June 29, 2019 (release notes).


Windows installer (.exe)
Based on Python 2.7 for 32 and 64 bit systems

Windows no installation required (.zip)
Unzip and run! Based on Python 2.7 for 32 and 64 bit systems

Some Python packages, notably PyGaze and PsychoPy, are not compatible with Python 3, and are therefore not available in the Python 3 packages of OpenSesame.

Windows installer (.exe)
Based on Python 3.6 for 64 bit systems

Windows no installation required (.zip)
Unzip and run! Based on Python 3.6 for 64 bit systems

Mac OS

Mac OS package (.dmg)
Based on Python 2.7 for 64 bit systems


For more information about the OpenSesame runtime for Android, see:


OpenSesame is available through the PPA. To add this repository to your software sources and install OpenSesame, run the following commands in a terminal:

sudo add-apt-repository ppa:smathot/cogscinl
sudo apt-get update
sudo apt-get install opensesame

Some commonly used packages are not available through the PPA. You can install them through pip:

pip install expyriment psychopy==1.85.3 python-pygaze opensesame-extension-osf opensesame-extension-osweb

On some older versions of Ubuntu, you may experience missing icons. If this happens, you can install the package gnome-icon-theme-full. (This package does not exist on recent versions of Ubuntu anymore.)

sudo apt-get install gnome-icon-theme-full

Arch Linux

Arch Linux packages are available in the Arch Linux user repository.

All platforms (pip)

To install OpenSesame from PyPi (Python package index), type:

pip install python-opensesame

Older versions

Older versions can be downloaded from GitHub releases:

Source code

The source code of OpenSesame is available on GitHub.


When (not) to update?

  • Update while developing and testing your experiment; it is always best to use the latest version of OpenSesame.
  • Do not update while running an experiment; that is, do not update while you are collecting data.
  • Run an experiment with the same version of OpenSesame that you used for developing and testing.

Manually upgrading packages

Tips for system administrators

  • When a new major version of OpenSesame is released (with a version ending in 0, e.g. 3.1.0), it is generally followed quickly by one or two maintenance releases (e.g. 3.1.1 and 3.1.2) that address major bugs. Therefore, if you are installing OpenSesame on systems that you do not update often, it is best to wait until the second or third maintenance release (e.g. 3.0.2, 3.1.3, etc.). That way you minimize the risk of rolling out a version of OpenSesame that contains major bugs.
  • The Windows installer allows you to silently install OpenSesame using the /S flag.
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