Expyriment is an open-source and platform independent light-weight Python library for designing and conducting timing-critical behavioural and neuroimaging experiments. The major goal is to provide a well-structured Python library for a script-based experiment development with a high priority on the readability of the resulting programme code. It has been tested extensively under Linux and Windows.

Expyriment is an all-in-one solution, as it handles the stimulus presentation, recording of I/O events, communication with other devices and the collection and preprocessing of data. It offers furthermore a hierarchical design structure, which allows an intuitive transition from the experimental design to a running programme. It is therefore also suited for students as well as experimental psychologists and neuroscientists with little programming experience.

Website: http://www.expyriment.org


Publications & citation

If you have used Expyriment in your work, please cite the following publication:

Krause, F., & Lindemann, O. (2014). Expyriment: A Python library for cognitive and neuroscientific experiments. Behavior Research Methods, 46(2), 416-428. doi:10.3758/s13428-013-0390-6

Main features

  • Easy syntax, very readable (due to Python)
  • Cross-platform (Linux, Windows, OS X)
  • Allows for fast and efficient programming of experiments (do more with less code)
  • A variety of standard stimuli (Text, Picture, Audio, Video etc.)
  • Keyboard, Mouse, Serial Port, Parallel Port and Gamepad support
  • Hierarchical structure of experimental units (Experiment, Blocks, Trials, Stimuli)

For a full documentation of all Expyriment functionality (i.e. all available modules, classes, methods, functions, constants, and attributes provided by the Expyriment Python package), please have a look at the API reference pages

Example code

Examples of full experiments can be found here.

Creating experiments, blocks, trials and stimuli:

exp = expyriment.design.Experiment()
block = expyriment.design.Block()
trial = expyriment.design.Trial()
stimulus = expyriment.stimuli.TextLine(text="Hello World")

Building a hierarchy between various structures:


Presenting stimuli:

for block in exp.blocks:
    for trial in block.trials:

Handling input devices:

button, rt = exp.keyboard.wait([expyriment.misc.constants.K_SPACE])

Logging data:

exp.data.add([button, rt])


Expyriment is free software and released under the Open Source GNU General Public Licence of the Free Software Foundation.

Source code repository

The Expyriment source code repository is currently hosted on GitHub. Get a local copy of this repository with this command:

git clone https://github.com/expyriment/expyriment.git

Suggestions and bug tracking

If you want to make suggestions to improve Expyriment or you found a bug, please post your comments to the Expyriment issues page or contact us directly by sending an email to info@expyriment.org.

Mailing lists

Expyriment newsletter: All users of Expyriment should subscribe to the Expyriment newsletter, since the project is still under development. All modifications and new versions will be announced via this mailing list. (Visit http://groups.google.com/group/expyriment or send an email to expyriment+subscribe@googlegroups.com).

Expyriment users mailing list: If you have questions regarding the installation, usage or documentation of Expyriment please don’t hesitate to contact the Expyriment users mailing list (visit http://groups.google.com/group/expyriment-users or send an email to expyriment-users+subscribe@googlegroups.com) or contact us directly by sending an email to info@expyriment.org.


The new official Expyriment support forum can be found at http://forum.expyriment.org.

Matrix/IRC channel

To ask questions or to have real-time discussions with other users and the developers you can also use our Matrix chat. The room is also accesible from IRC:

Server: irc.freenode.org
Channel: #expyriment

Social networks