Qt (/ˈkjuːt/ pronounced "cute") is a cross-platform application development framework for creating graphical user interfaces as well as cross-platform applications that run on various software and hardware platforms such as Linux, Windows, macOS, Android or embedded systems with little or no change in the underlying codebase while still being a native application with native capabilities and speed.

Qt is currently being developed by The Qt Company, a publicly listed company, and the Qt Project under open-source governance, involving individual developers and organizations working to advance Qt. Qt is available under both commercial licenses and open-source GPL 2.0, GPL 3.0, and LGPL 3.0 licenses.

Qt is used for developing graphical user interfaces (GUIs) and multi-platform applications that run on all major desktop platforms and mobile or embedded platforms. Most GUI programs created with Qt have a native-looking interface, in which case Qt is classified as a widget toolkit. Non-GUI programs can also be developed, such as command-line tools and consoles for servers. An example of such a non-GUI program using Qt is the Cutelyst web framework.

Qt supports various C++ compilers, including the GCC and Clang C++ compilers and the Visual Studio suite. It supports other languages with bindings or extensions, such as Python via Python bindings and PHP via an extension for PHP5, and has extensive internationalization support. Qt also provides Qt Quick, that includes a declarative scripting language called QML that allows using JavaScript to provide the logic. With Qt Quick, rapid application development for mobile devices became possible, while logic can still be written with native code as well to achieve the best possible performance.

Other features include SQL database access, XML parsing, JSON parsing, thread management and network support.

The latest version of the Qt Framework is Qt 6.9, which was released on 2 April 2025.

Also still supported are — for commercial users — 6.5 LTS, released on 3 April 2023, 6.2 LTS, released on 30 September 2021, and 5.15 LTS, released on 26 May 2020 – long-term support (LTS) versions are generally supported for three years with a commercial license, while 5.15 support was extended to five years for subscription license holders, and so it is supported until 26 May 2025. Additionally the KDE project provides unofficial support for, at least, Qt 5.15, i.e. not just for commercial users.

In 2017, the Qt Company estimated a community of about 1 million developers worldwide in over 70 industries.