This is a reminder that the first large batch of free time limited trials for free use of Psychtoolbox 3.0.20 and later for Apple macOS and Microsoft Windows will end very soon for all those machines on which version 3.0.20 was first used before start of April 2025.

Free trials for those machines will end on coming Monday the 14th of April 2025, and further use of the software will require a paid software subscription license key, which you can buy from our store, accessible from www.psychtoolbox.net.

Free trials started for initial installations since April will always end 14 days after initial use of Psychtoolbox version 3.0.20 or later on a given machine.

We strongly recommend upgrading any 3.0.20 Psychtoolbox to at least version 3.0.21.0, but in general to the very latest published version.

Buy now and receive a license at a low early-bird rate!

For questions and discussions, follow this link to the discussion thread on our user forum.

For answers to frequently asked questions, follow this link to the slowly building FAQ on our Wiki.