OpenSesame

OpenSesame is a tool to create experiments for psychology, neuroscience, and experimental economics.

Copyright, 2010-2025, Sebastiaan Mathôt and contributors.

http://osdoc.cogsci.nl/

About

OpenSesame is a graphical experiment builder. OpenSesame provides an easy to use, point-and-click interface for creating psychological/ neuroscientific experiments.

Features

• A user-friendly interface — a modern, professional, and easy-to-use graphical interface
• Online experiments — run your experiment in a browser with OSWeb
• AI — develop your experiments together with SigmundAI
• Python — add the power of Python to your experiment
• JavaScript — add the power of JavaScript to your experiment
• Use your devices — use your eye tracker, button box, EEG equipment, and more.
• Free — released under the GPL3
• Crossplatform — Windows, Mac OS, and Linux

Related repositories

OpenSesame relies on a number repositories that are all hosted by the Cogsci.nl organization on GitHub. The most important of these are:

• opensesame contains core OpenSesame functionality
• sigmund analyst is a code editor that provides various PyQt widgets used by OpenSesame
• opensesame-extension-sigmund integrates SigmundAI into the OpenSesame user interface
• osweb implements OSWeb, the online OpenSesame runtime
• opensesame-extension-osweb embeds OSWeb into the OpenSesame user interface
• datamatrix implements a tabular data structure that is used by the loop item
• qdatamatrix implements a Qt widget for editing datamatrix objects
• pseudorandom implements pseudorandomization/ randomization constraints

Branches

Each major version of OpenSesame lives in its own branch.

• gibson - 2.8
• heisenberg - 2.9
• ising - 3.0
• james - 3.1
• koffka - 3.2
• loewenfeld - 3.3
• milgram - 4.0
• nightingale - 4.1

Citations

• Mathôt, S., Schreij, D., & Theeuwes, J. (2012). OpenSesame: An open-source, graphical experiment builder for the social sciences. Behavior Research Methods, 44(2), 314-324. doi:10.3758/s13428-011-0168-7
• Mathôt, S., & March, J. (2022). Conducting linguistic experiments online with OpenSesame and OSWeb. Language Learning. doi:10.1111/lang.12509

License

OpenSesame is distributed under the terms of the GNU General Public License 3. The full license should be included in the file COPYING, or can be obtained from:

• http://www.gnu.org/licenses/gpl.txt

OpenSesame contains works of others. For the full license information, please refer to debian/copyright.

Documentation

Installation instructions and documentation are available on the documentation website ...

• http://osdoc.cogsci.nl/

... which is itself also hosted on GitHub:

• https://github.com/smathot/osdoc

Linux installer

The easiest way to install OpenSesame on Linux is to download and run the installer script. This will create a Virtual Environment, pip install OpenSesame and all dependencies into this environment, and add a Desktop file to your system to easily start Sigmund Analyst. To upgrade, simply run the script again.

Currently, the Linux installer is tested on Ubuntu 24.04.

bash <(curl -L https://github.com/open-cogsci/OpenSesame/raw/refs/heads/4.1/linux-installer.sh) --install