silx supports most operating systems and different versions of the Python programming language.

This table summarizes the support matrix of silx:


Python vers.

Qt and its bindings



PyQt5.9+, PySide6.4+, PyQt6.3+



PyQt5.9+, PySide6.4+, PyQt6.3+



PyQt5.9+, PySide6.4+, PyQt6.3+

For the description of silx dependencies, see the Dependencies section.

For all platforms, you can install silx with pip, see Installing with pip.

To install silx in a Virtual Environment, there is short version here-after and a longer description: Installing silx in a virtualenv.

You can also install silx from the source, see Installing from source.

Installing with pip#

To install silx (and all its dependencies), run:

pip install silx[full]

To install silx with a minimal set of dependencies, run:

pip install silx


Use pip’s --user option to install locally for the current user.


  • If numpy is not yet installed, you might need to install it first.

  • Replace the pip command with pip3 to install silx or any other library for Python 3.


The mandatory dependencies are:

The GUI widgets depend on the following extra packages:

silx.opencl further depends on OpenCL and the following packages too :

The complete list of dependencies with the minimal version is described in the requirement.txt at the top level of the source package.

Build dependencies#

In addition to run-time dependencies, building silx requires a C/C++ compiler, numpy and cython.

The complete list of dependencies for building the package, including its documentation, is described in the requirement-dev.txt at the top level of the source package.


Packages are available for a few distributions:

You can also follow one of those installation procedures:

Installing a Debian package#

silx is officially packaged in Debian and Ubuntu.

To install it, run apt-get install silx as root. The python3-silx package provides the library, while the silx package provides the executable (silx view, silx convert, …).

Unofficial (possibly more recent) packages are available for Debian 10 (Buster, amd64) and Ubuntu 20.04 (Focal, amd64 and ppc64le) in this repository: See information on how-to use this repository before running apt-get install silx.


Those packages are built automatically, hence not signed. You have to accept the installation of non-signed packages.

If the packages are not installed, it might be due to the priority list. You can display the priority list using apt-cache policy silx. If the Pin-number of is too low compared to other sources, see the “Information/Troubleshooting” section here, and start the update/install procedure again.


The simplest way of installing silx on Windows is to install it with pip, see Installing with pip:

pip install silx[full]

This assumes you have Python and pip installed and configured. If you don’t, read the following sections.

Alternatively, you can check:

Installing Python#

Download and install Python from

We recommend that you install the 64bit version of Python, which is not the default version suggested on the Python website. The 32bit version has limited memory, and also we don’t provide a binary wheel for it. This means that you would have to install silx from its sources, which requires you to install a C compiler first.

Configure Python as explained on to add the python installation directory to your PATH environment variable.

Alternative Scientific Python stacks exists such as WinPython or Anaconda. They all offer most of the scientific packages already installed which makes the installation of dependencies much easier.

Using pip#

Configure your PATH environment variable to include the pip installation directory, the same way as described for Python.

The pip installation directory will likely be C:\Python35\Scripts\.

Then you will be able to use all the pip commands listed below in a command prompt.


Make sure to use python3 to install silx (you might need to install python3).

Then, install silx with pip, see Installing with pip:

pip install silx[full]

This should work without issues, as binary wheels of silx are provided on PyPi.

Virtual Environment#

Virtual environments are self-contained directory trees that contain a Python installation for a particular version of Python, plus a number of additional packages. They do not require administrator privileges, nor root access.

To create a virtual environment, decide upon a directory where you want to place it (for example myenv), and run the venv module as a script with the directory path:

python3 -m venv  myenv

This will create the myenv directory if it doesn’t exist, and also create directories inside it containing a copy of the Python interpreter, the standard library, and various supporting files.

Once you’ve created a virtual environment, you may activate it.

On Windows, run:


On Unix or MacOS, run:

source myenv/bin/activate

You can install, upgrade, and remove packages using a program called pip within your virtual environment (see Installing with pip).

pip install silx[full]

Installing from source#

Building silx from the source requires some Build dependencies which may be installed using:

pip install -r

Building from source#

Source package of silx releases can be downloaded from the pypi project page.

After downloading the silx-x.y.z.tar.gz archive, extract its content:

tar xzvf silx-x.y.z.tar.gz

Alternatively, you can get the latest source code from the master branch of the git repository: silx-kit/silx

You can now build and install silx from its sources:

cd silx-x.y.z
pip uninstall -y silx
pip install . [--user]

Known issues#

There are specific issues related to MacOSX. If you get this error:

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 1335: ordinal not in range(128)

This is related to the two environment variables LC_ALL and LANG not being defined (or wrongly defined to UTF-8). To set the environment variables, type on the command line:

export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8

Advanced build options#

Advanced options can be set through the following environment variables:

Environment variable



Whether or not to compile Cython code with OpenMP support (default: True except on macOS where it is False)


Whether or not to force re-generating the C/C++ source code from Cython files (default: False).


Whether or not to use a cleaner locale independent implementation of by using _GNU_SOURCE=1 (default: False; POSIX operating system only).


Set it to put all dependencies as install_requires (For packaging purpose).


Comma-separated list of package names to remove from install_requires (For packaging purpose).


Boolean options are passed as True or False.

Package the build into a wheel and install it (this requires to install the build package):

python -m build --wheel
pip install dist/silx*.whl

To build the documentation, using Sphinx:

pip install .  # Make sure to install the same version as the source
sphinx-build doc/source/ build/html


To re-generate the example script screenshots, build the documentation with the environment variable DIRECTIVE_SNAPSHOT_QT set to True.


To format the code, use black.


To run the tests of an installed version of silx, run the following on the python interpreter:

import silx.test

To run the test suite of a development version, use the script at the root of the source project.

python ./