Research Scientist

The True Cost of PsychoPy Builder: A Closer Look

As scientific researchers execute cognitive tasks, behavioural experiments and psychological research in a growing virtual environment, understanding the costs associated with tools like the PsychoPy Builder becomes paramount. This article dissects these costs and offers advice for minimizing expenses.

A Look at the PsychoPy License Model

Pyschopy provides several resilient tools for creating and running online experiments, one of the outstanding ones is the PsychoPy Builder. The PsychoPy Builder is open source, which means it's freely available and users can contribute to its development. However, hosting and running experiments online via or using the cloud services (Pavlovia) incurs costs.

Costs for a 100-Participant Experiment

Imagine you're running an experiment with 100 participants. Aside from the time and resources you invest in the conception and execution, there are also monetary costs to consider. For example, if you use Pavlovia's cloud services for online experiments, the participant per hour (PPH) cost is around $1.00. If your study were to last an hour, this would scale up to $100.00 for 100 individuals.

Hidden Costs - The Silent Resource Drain

PsychoPy Builder might at first glance seem to have minimal costs associated with it. However, it's essential to recognize the "hidden" costs that aren't readily visible. These can include expenses related to data management, time spent debugging or modifying scripts for complex experiments, and replicating studies.

Furthermore, many researchers and experiment designers find themselves limited by their coding skills, causing them to spend more time learning Python, the language of PsychoPy Builder, and jsPsych, another tool used in online experiments. This, too, is a cost, in terms of time spent.

Tips to Reduce Costs

Despite the multitude of costs one may incur when running behavioral experiments or cognitive tasks, there are certainly ways to minimize them. Working in collaboration with other scientists can help distribute these costs. Utilizing existing templates or building upon previous experiments instead of creating a project from scratch can also limit expenses. Finally, optimizing your study to be as short and efficient as possible will reduce the PPH cost.


In psychology research and particularly in the use of PsychoPy Builder for online and remote studies, it's crucial to be cognizant of both the overt and hidden costs. By understanding these potential financial burdens and using strategies to cut costs, we can make research accessible and feasible for more scientists worldwide.

Related articles: