GTK — The GTK toolkit

General information

GTK is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK is suitable for projects ranging from small one-off projects to complete application suites.

GTK is a free and open-source software project. The licensing terms for GTK, the GNU LGPL, allow it to be used by all developers, including those developing proprietary software, without any license fees or royalties.

GTK is hosted by the GNOME project (thanks!) and used by a wide variety of applications and projects.

The official download location

• https://download.gnome.org/sources/gtk/

The official web site

• https://www.gtk.org

The official developers blog

• https://blog.gtk.org

Discussion forum

• https://discourse.gnome.org/c/platform/core/

Nightly documentation can be found at - Gtk: https://gnome.pages.gitlab.gnome.org/gtk/gtk4/ - Gdk: https://gnome.pages.gitlab.gnome.org/gtk/gdk4/ - Gsk: https://gnome.pages.gitlab.gnome.org/gtk/gsk4/

Nightly flatpaks of our demos can be installed from the GNOME Nightly repository:

flatpak remote-add --if-not-exists gnome-nightly https://nightly.gnome.org/gnome-nightly.flatpakrepo
flatpak install gnome-nightly org.gtk.Demo4
flatpak install gnome-nightly org.gtk.WidgetFactory4
flatpak install gnome-nightly org.gtk.IconBrowser4

Building and installing

In order to build GTK you will need:

• a C11 compatible compiler
• Python 3
• Meson
• Ninja

You will also need various dependencies, based on the platform you are building for:

• GLib
• GdkPixbuf
• GObject-Introspection
• Cairo
• Pango
• Epoxy
• Graphene
• Xkb-common

If you are building the Wayland backend, you will also need:

• Wayland-client
• Wayland-protocols
• Wayland-cursor
• Wayland-EGL

If you are building the X11 backend, you will also need:

• Xlib, and the following X extensions:
  • xrandr
  • xrender
  • xi
  • xext
  • xfixes
  • xcursor
  • xdamage
  • xcomposite

Once you have all the necessary dependencies, you can build GTK by using Meson:

$ meson setup _build
$ meson compile -C_build

You can run the test suite using:

$ meson test -C_build

And, finally, you can install GTK using:

$ sudo meson install -C_build

Complete information about installing GTK and related libraries can be found in the file:

docs/reference/gtk/html/gtk-building.html

Or online

Building from git

The GTK sources are hosted on gitlab.gnome.org. The main development branch is called main, and stable branches are named after their minor version, for example gtk-4-10.

How to report bugs

Bugs should be reported on the issues page.

In the bug report please include:

• Information about your system. For instance:

• which version of GTK you are using

• what operating system and version
• what windowing system (X11 or Wayland)
• what graphics driver / mesa version
• for Linux, which distribution
• if you built GTK, the list of options used to configure the build

Most of this information can be found in the GTK inspector.

And anything else you think is relevant.

• How to reproduce the bug.

If you can reproduce it with one of the demo applications that are built in the demos/ subdirectory, on one of the test programs that are built in the tests/ subdirectory, that will be most convenient. Otherwise, please include a short test program that exhibits the behavior. As a last resort, you can also provide a pointer to a larger piece of software that can be downloaded.

• If the bug was a crash, the exact text that was printed out when the crash occurred.

• Further information such as stack traces may be useful, but is not necessary.

Contributing to GTK

Please, follow the contribution guide to know how to start contributing to GTK.

If you want to support GTK financially, please consider donating to the GNOME project, which runs the infrastructure hosting GTK.

Release notes

The release notes for GTK are part of the migration guide in the API reference. See:

• 3.x release notes
• 4.x release notes

Licensing terms

GTK is released under the terms of the GNU Lesser General Public License, version 2.1 or, at your option, any later version, as published by the Free Software Foundation.

Please, see the COPYING file for further information.

GTK includes a small number of source files under the Apache license: - A fork of the roaring bitmaps implementation in gtk/roaring - An adaptation of timsort from python in gtk/timsort