Download, Installation, and Update

Make sure to familiarize yourself with the System requirements, so your system is set up with suitable hardware and additional required software before installing Psychtoolbox itself.

In order to install and use the Psychtoolbox, you must already have Matlab or Octave installed on your computer, unless you install for Octave on Linux via the NeuroDebian repositories. If you already have Matlab or Octave installed, start it up and read on. On Windows you must have installed GStreamer 1.22.5 MSVC edition or later versions.



First, you should make sure you don’t already have Psychtoolbox-3. Type the following in the Matlab command window:

>> PsychtoolboxVersion

The first number in the output is the version number. If it is 3.0.8 or greater, then you have Psychtoolbox-3. Pick one:

  1. If you have an older version of Psychtoolbox than 3.0.8, remove it by following the instructions in the next section, Removing Old Versions

  2. If you don’t have Psychtoolbox-3 at all, read the Installation Instructions below.

  3. If you do have it, skip down to the Staying Up-to-Date section below.

Removing Old Versions of Psychtoolbox

If you have an old version of Psychtoolbox installed, the installer will prompt you if it should automatically delete those version from your file system and do so if you agree. If you want to delete the folder manually, apply the following procedure.

To find the Psychtoolbox installation directory, type the following in the Matlab command window:

>> PsychtoolboxRoot

Find that folder and drag it to the Trash or Recycling Bin. Then type pathtool in the Matlab command window. This will bring up a dialog box with a list of folders that Matlab searches to find commands. Select all the folders that have “Psychtoolbox” in the name and click the “Remove” button, followed by the “Save” button to save the changes.

Installation Instructions

These are simple instructions to get you up and running with the Psychophysics Toolbox on a computer. It is assumed that you already have Matlab or Octave installed on your computer, or you are installing for Octave on Linux via the NeuroDebian repositories. See the System Requirements.



Recommended: Psychtoolbox for Linux has been packaged by the NeuroDebian team and is available in the following repositories:

Usually reasonably up to date, tracks most recent official PTB beta releases - recommended for most “bread and butter” use cases:

NeuroDebian provides installation instructions on its website when you click on the links for Octave or Matlab above.

If you installed Matlab before installing Psychtoolbox for Matlab from NeuroDebian, the installation will ask you for the location of your Matlab installation, and if you want it to rename some Matlab libraries to fix compatibility issues caused by Matlab. Answer YES to these questions, this is crucial! Otherwise hardware accelerated graphics will likely not work with Matlab later on.

If you installed Matlab after installing Psychtoolbox, or after you have upgraded Matlab to a more recent version you must rerun this Matlab compatibility fixing script via: sudo dpkg-reconfigure matlab-support.

As opposed to Octave, the Psychtoolbox for Matlab won’t get permanently added to your Matlab path by default. You can execute the following command from a terminal to run a Matlab session with the standard system-wide Psychtoolbox installation added to the path for the duration of that session (this path is not customizable easily):


You could then execute Matlabs savepath command to add it permanently if you wanted, or after customizing it for your special needs, or in the typical case simply call ptb3-matlab whenever you need to run a standard Psychtoolbox work session.

At the end of a successfull NeuroDebian installation, after first launch of your Octave or Matlab with the new Psychtoolbox, run the script PsychLinuxConfiguration from within Matlab or Octave, and follow the interactive instructions and questions to optimize your Linux system for data collection.

Only for basic testing and very simple use cases: Debian and Ubuntu and potentially other Debian/Ubuntu based Linux distributions also provide Psychtoolbox directly from their repositories, but these Psychtoolbox packages are usually very outdated, often years behind versions, and they support GNU Octave only, no Matlab, and not certain functions like Eyelink or Datapixx:

The packages in the main Debian and Ubuntu archives only ship with GNU Octave support, hence the package to install is octave-psychtoolbox-3.

In general using the NeuroDebian repo above is more convenient and provides more up to date packages for Octave and Matlab, but the distribution packages will do for a quick test drive, e.g., from within a Live Linux system, booted from a USB flash drive, for quick compatibility testing.

If you choose installation from the distribution directly, bypassing NeuroDebian, after package installation, run the script PsychLinuxConfiguration from within Octave once, and follow the interactive instructions and questions to optimize your Linux system for data collection. You may be able to do without this step for a quick basic test drive or maybe for pure student training without need for high timing precision or precise low-level control of your hardware and special equipment.

The advantage of all the above methods is that third-party dependencies are automatically installed by the package manager.

Manual download

See section Alternate Download below for how to download zip files instead.

After basic Linux installation - further tweaks:

Another recommendation is to install a low-latency Linux kernel for optimized timing, e.g., on Ubuntu flavors and probably also Debian flavors:

sudo apt install linux-lowlatency

Optimization of the display server settings for good visual timing is achieved by following the Linux instructions in “» help SyncTrouble” and by running the helper scripts XOrgConfCreator and XOrgConfSelector to automatically create and install optimized xorg.conf configuration files for the X-Server. This is especially useful for hybrid graphics laptops and multi-display setups.

Additional tips for installing and using Psychtoolbox on Linux.


Execute steps 1 and 2 below and then skip to Alternate Download below for how to download zip files instead.

Filesystem locations given here are examples. You could choose other disc drives or folders of your liking instead:

  1. You must install the 64-Bit GStreamer-1.22.5 MSVC (or later versions) runtime from even if you do not need multi-media support! Do not install the MINGW variant, it will not work, but likely crash! Make absolutely sure that you install all offered packages. Read help GStreamer carefully for this purpose, before downloading and installing GStreamer.

    If you intend to use Octave, you will need to delete the following DLL files from the C:\Program Files\GNU Octave\Octave-7.3.0\mingw64\bin\ folder: opengl32.dll – Otherwise hardware accelerated visual stimulation will not work.

  2. You may also need to install the Microsoft Runtime Libraries for MSVC 2015-2019 if you use Matlab instead of Octave and those have not been installed already by other software on your system. For a few use cases you may even need those if you use Octave. You can find installers for these at Microsoft’s site beforehand. Otherwise, if our installer aborted half-ways, follow the instructions it prints to the console. Or simply click this link to get a copy bundled with Psychtoolbox


Execute step 1 and then skip to Alternate Download below for how to download zip files instead.

  1. If you intend to use multi-media functions, or if you want fast, high-quality, cross-platform, consistent text rendering with Matlab, you must install the 64-Bit GStreamer-1.18.5 or later runtime from Make absolutely sure that you install all offered packages. Read help GStreamer carefully for this purpose, before downloading and installing GStreamer.

Download of Psychtoolbox as a zip file

If you don’t want to download manually via GitHub (expert approach), or via convenient Linux package respositories, the typical approach is download of a zip file (or tar.gz file). We provide “Source Code” zip or tar.gz files, which contain a given Psychtoolbox release, including the full source code. These are large, due to inclusion of the source code.

More often you’ll want to download the smaller zip file with the version number for only the Psychtoolbox standard folder (ie. without source code), e.g., something named like

The “Assets” section of each Psychtoolbox GitHub release contains the download links.

Click this link to go to the downloads page for all official releases.

Then read on how to set up your manually downloaded copy of Psychtoolbox in the following section. This also applies to a manually git cloned Psychtoolbox.

Installation without Download or after zip file or GitHub git download

Note: You still need to execute operating-system dependent or Matlab/ Octave dependent setup steps like installing GStreamer, or other packages and configuration steps mentioned above. Essentially, do everything operating system dependent mentioned in the previous sections before proceeding here.

Tip: If you already have downloaded a copy of the Psychtoolbox folder onto a local computer and want to replicate that installation onto other computers, then you don’t need to download the toolbox again. Instead, simply copy the Psychtoolbox folder to the other target machines.

Next, startup Matlab or Octave on the machine, change Matlab’s or Octave’s working directory to the Psychtoolbox folder (cd command) and then type SetupPsychtoolbox.

(see SetupPsychtoolbox or type help SetupPsychtoolbox). The SetupPsychtoolbox script will setup your local Psychtoolbox folder for use with Matlab or Octave.

Staying Up-to-Date

If you installed Psychtoolbox-3 for Linux from NeuroDebian, Debian or Ubuntu, your operating system will automatically notify you of new Psychtoolbox releases. After your approval, it will automatically upgrade the toolbox to the new version.

A manually Git cloned Psychtoolbox can be upgraded via git pull, and then rerunning SetupPsychtoolbox as mentioned in the previous section.

After Download and installation

You should now have a complete Psychtoolbox installation. To start learning about the Psychtoolbox, use the help command. For example,

>> help Psychtoolbox will list the categories of functions in the toolbox, and

>> help PsychDemos will list all the demos available.

A PDF file with the presentation slides of an introduction into Psychtoolbox-3: Talk slides of Psychtoolbox presentation, given at ECVP 2013 Bremen

More detailled information can be found in the Psychtoolbox subfolder named PsychDocumentation of your Psychtoolbox installation.

More Information

Download problems

If you need timely expert support in resolving download or installation issues, we also offer paid support under this link. If everything else fails, contact the Psychtoolbox forum with a description of what you tried.

Access to Archived Versions of PTB-3

You can also choose to install specific old versions of Psychtoolbox-3 by cloning or downloading the correspondingly named Git branches on our GitHub repository

E.g., to download Psychtoolbox-3.0.12 you would checkout or download the branch named ‘Psychtoolbox-3.0.12’. A list of older versions can be found at the bottom of the page found here. This only works for versions since 3.0.10.