OpenSesame videos
Python videos
Supported by Supported by



All download options

The latest development version is 3.3.0a57 Lentiform Loewenfeld, released on Unreleased (release notes).


The recommended download is based on Python 3.7. The installer and .zip packages are identical, except for the installation.

Windows installer (.exe)
Based on Python 3.7 for 64 bit systems

Windows no installation required (.zip)
Unzip and run! Based on Python 3.7 for 64 bit systems

Some Python packages are not compatible with Python 3. If you want to use those, please download the Python 2.7 package below. Note: As of January 1, 2020, Python 2.7 is no longer maintained.

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

Mac OS

Mac OS packages are not yet available. For now, you can install OpenSesame 3.3 on Mac OS through Anaconda (see below).

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


OpenSesame 3.3 is available through the Rapunzel 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/rapunzel
sudo apt-get update
sudo apt-get install python3-opensesame opensesame-extension-osf opensesame-extension-osweb opensesame-plugin-psychopy
# To install also rapunzel, the OpenSesame-based code editor
sudo apt-get install python3-rapunzel

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

pip install psychopy expyriment

Arch Linux

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

Pip / PyPi (cross-playform)

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

pip install python-opensesame

Anaconda (cross-platform)

First, create a new Python environment for OpenSesame (optional):

conda create -n opensesame-py3 python=3.7.3  # For Python 2: ptyhon=2.7.15
conda activate opensesame-py3

Next, add the relevant channels (cogsci) and (conda-forge) and install all relevant packages:

conda config --add channels cogsci --add channels conda-forge
conda install python-opensesame opensesame-extension-osf opensesame-extension-osweb opensesame-plugin-psychopy psychopy rapunzel

PyGaze, a Python eye-tracking library, is only available on Python 2.

conda install python-pygaze

Older versions

Older versions can be downloaded from GitHub releases:

Source code

The source code of OpenSesame is available on GitHub.


Which version of Python to use?

OpenSesame is currently built with Python 3.7.3 (standard package) and Python 2.7.15.

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.
Supported by Supported by