>30k users >4k citations >190 github contributors >150 pavlovia licences
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Free software for creating colorful experiments.

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How is PsychoPy® Free?


What users say

See all testimonials.

Davide Massida

via twitter

"PsychoPy is one of those things that improve the life of an experimental psychologist. Really. #python #neuroscience"

Harriet Allen

Professor, University of Nottingham

"What made me switch was the combination of Builder and Coder options. Students are not scared of the Builder, but I can still write code when needed (and even hide it in student experiments).""

Nate Vack

Research Programmer, UW-Madison

"It's wonderful to have a product that makes stimulus presentation easy (and is free!)...""

Fenja Ziegler

Senior Lecturer, University of Lincoln

"...easy to customise with a bit of scripting, a helpful user community, can be explained to a student in an hour or so..."

Micah Allen

Post-doc, UCL

"I love psychopy! I used it for one previous fMRI experiment and found the language extremely easy to use..."

How is PsychoPy Free?

The PsychoPy desktop application is free to download and run for in lab studies. PsychoPy® was written by scientists for scientists, the code underlying the software is open source on github, so even if you want to change the software you can!

As PsychoPy grew in popularity, it became clear that developing it "as a side project" in researchers spare time was not going to be sustainable. We now have a company, Open Science Tools, to sustain professional development. We have three main sources of revenue:

  • Pavlovia.org licenses: A platform for hosting your study online if you want to collect data via a URL link.
  • Consultancy: Yes, you can pay us to make your task for you!
  • Workshops: We can run custom training workshops for your department/team.

So, if you enjoy PsychoPy and would like to support its maintenance, please consider supporting us through one of these revenue streams. We try to keep our rates low-cost and affordable, whilst generating enough revenue to have a team of staff professionally develop PsychoPy and support users.

Easy enough for teaching

Universities all over the world are using PsychoPy® for teaching students about experiments

Precise enough for psychophysics

Hardware accelerated graphics, best-in class timing, and calibration tools built in

  • Fantastic timing precision (see the timing mega-study for comparisons)!
  • Time and update your stimulus on every screen refresh!
  • Tools to help monitor calibration and wide range of units
  • Hardware-accelerated graphics for stimuli that can be updated on the fly
  • Access to button boxes when you need the utmost precision
  • Automated logging for you to what happened and when
  • OpenGL (and shaders) ready for use when you low-level access to graphics

Flexible enough for everything else

PsychoPy® is great for:
  • Dynamic, interactive studies: Free yourself from simple static stimuli! You can update your stimulus interactively on every screen refresh!
  • Neuroimaging: Send and receive triggers to your hardware at precise times
  • Eye-tracking: Access to wide range of hardware (eye trackers, button boxes, trigger systems...)


Want to run your study on the web, so participants can access it anywhere?

Did you know PsychoPy® has a JavaScript sister library? PsychoJS, this means you can create a version of your experiment to run in a browser, after that you can use Pavlovia.org to host it!

Pavlovia is:

  • A secure server to host your experiment online.
  • An Open Access library of experiment demos.
  • A place to create feature rich surveys using Pavlovia Surveys
  • Upload that to Pavlovia.org (with easy tools built into the PsychoPy app)
  • Give participants your URL and run your study in the browser!
  • You can recruit participants using Sona, Prolific, Mechanical Turk or similar systems.