| Reference | Downloads | Github

Pavlovia pricing details

#1 Pricing

Development and maintenance of has been funded by the Wellcome Trust so far but that will draw to an end this year and we have to start planning for sustainable development going forwards.

As well as making our tools as open as we can, we also support an open pricing model. We want to charge as little as we possible while providing a professional level of service, and we will be completely open about the prices being charged and how the revenue will be used. We hope you’ll find that refreshing.

When will no longer be free?

From 1st September 2019 experiments hosted on Pavlovia will only collect data for you on projects where the owner has sufficient participant credits or belongs to a university with a site license.


The standard charge for use of Pavlovia is through Participant Credits, which will be charged for each participant completing your study. You buy credits in advance. As each participant completes their run a credit is consumed. Scientists can consult their dashboard to monitor their remaining credits and the credits consumed by each of their projects.

Piloting will be free but the saving of data will be limited while a project is in piloting mode.

Participant Credits: £0.20 per participant

Yes, a 50-participant study will cost just £10!

Site License: £1500 per year

For universities that want to make Pavlovia free for all users there is also a site license. This costs £1500 per year with no restrictions (we think this is also remarkably cheap compared with any similar product).

Note that you can buy credits or site licenses in advance (see Purchasing from left-over cash) using end-of-year funds.

Why must we charge?

Pavlovia was built on a grant from The Wellcome Trust, with support from University of Nottingham. So far, no charge has been made to use Pavlovia to run experiments. It isn’t sustainable for it to remain free, however: the Wellcome grant will soon come to an end, and we need to cover the server costs and keep developers on staff.

In order to continue maintaining and developing the site and its associated tools to a professional standard, we therefore need to charge a small fee to each user or department. We will keep those fees considerably lower than any other provider of experiment hosting, while ensuring that we are able to continue providing this service and improving it. Pavlovia is not aiming to generate large profits, just a sustainable income to pay staff to maintain and develop the tools to a professional level.

PsychoPy will always remain free and open-source, as will PsychoJS. A real advantage of the Pavlovia service is that the income it generates will also be used to support development of those packages, as well as Pavlovia itself.

Supporting Open Science software tools

We know there are a number of alternatives for running experiments online. Pavlovia is a fraction of the cost of the commercial services, and easier than setting up and maintaining your own server.

The revenue that generates will be used entirely to support Pavlovia, PsychoPy and other open-science projects like jsPsych and lab.js.

There are a lot of exciting developments you’ll be seeing over the next few years, and the more people that are on-board with this project and buying credits, the more these services can be developed and polished!

Purchasing from left-over cash

You can buy your credits and site licenses at any point in the year (e.g. when your budget is about to roll-over).

For a site-license you can decide the date you want it to start, so you could buy the license in July (when your budget is about to get swallowed up) and, say, set the license to start on 1st September.

For individual purchases, participant credits will not expire, so you can also feel free to buy credits when you have the spare budget and spend them when you need them in the future.