Licenses Used in Qt

Qt contains some code that is not provided under the GNU Lesser General Public License (LGPL) or the Qt Commercial License, but rather under specific licenses from the original authors.

The Qt Company gratefully acknowledges these and other contributions to Qt. We recommend that programs that use Qt also acknowledge these contributions, and quote these license statements in an appendix to the documentation.

Note: You only need to comply with (and acknowledge) the licenses of the third-party components that you are using with your application. Click the name of the component to see the licensing details.

Third-party Licenses

The following table lists parts (modules) of Qt 6.5.3 that incorporate code licensed under third-party open-source licenses:

Qt 3D

Dear ImGui - ProggyClean.ttf	MIT License
Dear ImGui - stb	MIT License or Public Domain
Dear ImGui, version v1.66b	MIT License

Qt 5 Core Compatibility APIs

Text Codec: EUC-JP	BSD 2-clause "Simplified" License
Text Codec: EUC-KR	BSD 2-clause "Simplified" License
Text Codec: GBK	BSD 2-clause "Simplified" License
Text Codec: ISO 2022-JP (JIS)	BSD 2-clause "Simplified" License
Text Codec: Shift-JIS	BSD 2-clause "Simplified" License
Text Codec: TSCII	BSD 2-clause "Simplified" License
Text Codecs: Big5, Big5-HKSCS	BSD 2-clause "Simplified" License

Qt Bluetooth

BlueZ

GNU General Public License v2.0 only (This does not force user code to be GPL'ed. For more info see details.)

Qt Core

BLAKE2 (reference implementation), version 54f4faa4c16ea34bcd59d16e8da46a64b259fc07	Creative Commons Zero v1.0 Universal or Apache License 2.0
Data Compression Library (zlib), version 1.3	Zlib License
Easing Equations by Robert Penner	BSD 3-clause "New" or "Revised" License
Efficient Binary-Decimal and Decimal-Binary Conversion Routines for IEEE Doubles, version 3.3.0	BSD 3-clause "New" or "Revised" License
KWin, version 5.13.4	BSD-3-Clause
MD4	Public Domain
MD5	Public Domain
PCRE2 - Stack-less Just-In-Time Compiler, version 10.42	BSD 2-clause "Simplified" License
PCRE2, version 10.42	BSD 3-clause "New" or "Revised" License with PCRE2 binary-like Packages Exception
QEventDispatcher on macOS	BSD 3-clause "New" or "Revised" License
Secure Hash Algorithm SHA-1	Public Domain
Secure Hash Algorithm SHA-3 - Keccak, version 3.2	Creative Commons Zero v1.0 Universal
Secure Hash Algorithm SHA-3 - brg_endian, version https://github.com/BrianGladman/sha/ commit 4b9e13ead2c5b5e41ca27c65de4dd69ae0bac228	BSD 2-clause "Simplified" License
Secure Hash Algorithms SHA-384 and SHA-512	BSD 3-clause "New" or "Revised" License
SipHash Algorithm	Creative Commons Zero v1.0 Universal
TinyCBOR, version 0.6.0	MIT License
Unicode Character Database (UCD), version 30	Unicode License Agreement - Data Files and Software (2016)
Unicode Common Locale Data Repository (CLDR), version v43	Unicode License Agreement - Data Files and Software (2016)
extra-cmake-modules, version 5.84.0	BSD-3-Clause
forkfd	MIT License

Qt D-Bus

libdus-1 headers, version dbus-1.13.12

Academic Free License v2.1, or GNU General Public License v2.0 or later

Qt GUI

Adobe Glyph List For New Fonts, version 1.7	BSD 3-Clause "New" or "Revised" License
Anti-aliasing rasterizer from FreeType 2	Freetype Project License or GNU General Public License v2.0 only
Bitstream Vera Font, version 1.10	Bitstream Vera Font License
Cocoa Platform Plugin	BSD 3-clause "New" or "Revised" License
DejaVu Fonts, version 2.37	Bitstream Vera Font License
Freetype 2 - Bitmap Distribution Format (BDF) support	MIT License
Freetype 2 - Portable Compiled Format (PCF) support	MIT License and MIT Open Group variant
Freetype 2 - zlib	Zlib License
Freetype 2, version 2.13.2	Freetype Project License or GNU General Public License v2.0 only
HarfBuzz-NG, version 8.2.0	MIT License
IAccessible2 IDL Specification, version 1.3.0	BSD 3-clause "New" or "Revised" License
LibJPEG-turbo, version 3.0.0	Independent JPEG Group License and BSD 3-Clause "New" or "Revised" License and zlib License
LibPNG, version 1.6.40	Libpng License and PNG Reference Library version 2
MD4C, version 0.4.8	MIT License
Native Style for Android	Apache License 2.0
OpenGL ES 2 Headers, version Revision 27673	MIT License
OpenGL Headers, version Revision 27684	MIT License
Pixman, version 0.17.12	MIT License
Smooth Scaling Algorithm	BSD 2-clause "Simplified" License and Imlib2 License
Vulkan API Registry, version 1.3.223	Apache License 2.0 or MIT License
Vulkan Memory Allocator, version 3.0.1	MIT License
WebGradients	MIT License
Wintab API	LCS-Telegraphics License
X Server helper	X11 License and Historical Permission Notice and Disclaimer
XCB-XInput	MIT License
sRGB color profile icc file	International Color Consortium License

Qt Image Formats

TIFF Software Distribution (libtiff), version 4.6.0	Libtiff License
WebP (libwebp), version 1.3.2	BSD 3-clause "New" or "Revised" License

Qt Network

The Public Suffix List, version 1a4824549b093abc3077205ae5386ed57f73806d, fetched on 2023-09-20	Mozilla Public License 2.0
libpsl - C library to handle the Public Suffix List, version 664f3dc85259ec65e30248a61fa1c45b7b0e4c3f	BSD 3-clause "New" or "Revised" License

Qt OPC UA

Open62541, version 1.3.4

Mozilla Public License 2.0 and Creative Commons Zero v1.0 Universal and Creative Commons Attribution Non Commercial Share Alike 4.0 International and BSD 3-Clause "New" or "Revised" License and Apache License 2.0 and MIT License

Qt Positioning

Clip2Tri Polygon Triangulation Library	MIT License
Clipper Polygon Clipping Library, version 6.4.2	Boost Software License 1.0
Poly2Tri Polygon Triangulation Library	BSD 3-clause "New" or "Revised" License

Qt QML

JavaScriptCore Macro Assembler

BSD 2-clause "Simplified" License

Qt Quick 3D

Godot Engine: Fog	MIT License
Godot Engine: ProceduralSky	MIT License
Intel Embree, version 3.13.3	Apache License 2.0
Open Asset Import Library, version 5.2.5	BSD 3-clause "New" or "Revised" Licensee
Tiny OpenEXR, version v1.0.7	BSD 3-clause "New" or "Revised" License
meshoptimizer, version v0.18	MIT License
xatlas, version 16ace528acd2cf1f16a7c0dde99c42c486488dbe	MIT License

Qt Quick 3D Physics

NVIDIA PhysX SDK, version PhysX_4.1.2.29882248

BSD 3-Clause "New" or "Revised" License

Qt Quick Controls

Shadow values from Angular Material

MIT License

Qt SQL

SQLite, version 3.43.1

Public Domain

Qt SVG

XSVG	Historical Permission Notice and Disclaimer - sell variant

Qt Spatial Audio

Eigen, version 3.4.0	Mozilla Public License 2.0 and BSD 3-Clause "New" or "Revised" License
Resonance Audio, version e225aedb5ec7	Apache License 2.0
pfft, version 38946c766c1a	BSD 3-Clause "New" or "Revised" License

Qt Test

Catch2, version 2.13.10	Boost Software License 1.0
Cycle	MIT License
Linux Performance Events, version 3.7	GNU General Public License v2.0 only with Linux Syscall Note
Valgrind, version 3.20.0	BSD 4-clause "Original" or "Old" License

Qt Virtual Keyboard

OpenWnn	Apache License 2.0
PinyinIME	Apache License 2.0
Traditional Chinese IME (tcime)	Apache License 2.0 and BSD 3-clause "New" or "Revised" License

Qt Wayland Compositor

Presentation Time Protocol, version 1	MIT License
Wayland EGLStream Controller Protocol, version 1.1.1	MIT License
Wayland Fractional Scale Protocol, version 1	MIT License
Wayland Fullscreen Shell Protocol, version unstable v1	MIT License
Wayland IVI Extension Protocol, version 1.9.1	MIT License
Wayland Linux Dmabuf Unstable V1 Protocol, version unstable v1, version 3	MIT License
Wayland Pointer Gestures Protocol, version unstable v1, version 2	MIT License
Wayland Primary Selection Protocol, version 1	MIT License
Wayland Protocol, version 1.19.0	MIT License
Wayland Scaler Protocol, version 2	MIT License
Wayland Tablet Protocol, version unstable v2, version 1	MIT License
Wayland Text Input Protocol v1, version unstable v1	MIT License
Wayland Text Input Protocol v2, version unstable v2	HPND License
Wayland Text Input Protocol, version unstable v4, WIP	HPND License
Wayland Viewporter Protocol, version 1	MIT License
Wayland XDG Foreign Protocol, version 1	MIT License
Wayland XDG Output Protocol, version unstable v1, version 3	MIT License
Wayland XDG Shell Protocol, version 1.18	MIT License
Wayland xdg-activation Protocol, version unstable v1, version 1	MIT License
Wayland xdg-decoration Protocol, version unstable v1, version 1	MIT License

Qt WebEngine

AXE-CORE Accessibility Audit	MPL 2.0
Abseil	Apache 2.0
Alliance for Open Media Video Codec	BSD
Almost Native Graphics Layer Engine	BSD
Android Explicit Synchronization	Apache 2.0
BoringSSL	BSDish
Brotli	MIT
CRC32C	New BSD
Chromium License	BSD
CodeMirror 6	MIT
Compact Encoding Detection	Apache 2.0
Compact Language Detector v3	Apache 2.0
Crashpad	Apache 2.0
Dawn	Apache 2.0
Devtools-Frontend	BSD
Emoji Segmenter	Apache 2.0
Expat XML Parser	MIT
Fiat-Crypto: Synthesizing Correct-by-Construction Code for Cryptographic Primitives	MIT
FlatBuffers	Apache 2.0
Google Double Conversion	BSD
Headers for the Windows 10 WebAuthn API (webauthn.dll)	MIT
Lighthouse	Apache License 2.0
OTS (OpenType Sanitizer)	BSD
One Euro Filter	BSD
PDFium	BSD
PFFFT: a pretty fast FFT.	BSD-like
Perfetto	Apache2
Protocol Buffers	BSD
Recurrent neural network for audio noise reduction	BSD 3-Clause
Snappy: A fast compressor/decompressor	New BSD
The Chromium Project	BSD 3-clause "New" or "Revised" License
The Incremental Distributed Point Functions library	Apache 2.0
V8 fork of fdlibm	Fdlibm license
Volk Meta loader for Vulkan API	MIT
Vulkan Deps	BSD
VulkanMemoryAllocator	MIT
WebKit	BSD and LGPL v2 and LGPL v2.1
WebM container parser and writer.	BSD
WebP image encoder/decoder	BSD
WebRTC	BSD
Windows Template Library (WTL)	Microsoft Permissive License
Wuffs (Wrangling Untrusted File Formats Safely)	Apache 2.0
cpuinfo	BSD
dav1d is an AV1 decoder :)	2-Clause BSD
dynamic annotations	BSD
ffmpeg	LGPL 2.1
fontconfig	MIT
google-glog's symbolization library	BSD
harfbuzz-ng	MIT
hunspell	MPL 1.1/GPL 2.0/LGPL 2.1
iccjpeg	Custom license
icu	MIT
inspector protocol	BSD
ipcz	BSD
jsoncpp	MIT
libavif - Library for encoding and decoding .avif files	2-Clause BSD
libevent	BSD
libgav1	Apache 2.0
libpng	Libpng license
libsrtp	3-clause BSD
libvpx	BSD
libxml	MIT
libxslt	MIT
libyuv	BSD
mesa_headers	MIT and SGI Free Software B License Version 2.0
modp base64 decoder	BSD
opus	BSD
re2 - an efficient, principled regular expression library	BSD 3-Clause
sqlite	Public domain
woff2	MIT
xdg-mime	Academic Free License version 2.0 or LGPL v2
xdg-user-dirs	MIT
zlib	Custom license

Shader Tools

SPIRV-Cross, version sdk-1.3.216.0	Apache License 2.0 and Khronos License
glslang, version 11.10.0	BSD 3-Clause "New" or "Revised" License, and Khronos License, and Apache License 2.0, and GNU General Public License v3.0 or later with Bison exception 2.2, and NVIDIA 2002 License

Additional Information

The following table lists related documents, such as information about Trademarks and other licenses used in parts of Qt.

Android GNU C++ Run-time Licensing	Provides additional information about the licensing of run-time dependencies of Qt for Android
LLVM Attribution	University of Illinois/NCSA Open Source License, BSD licenses
License Changes	Information about changes of licenses in Qt and Third Party Modules
Macros for Building with CMake	BSD 3-clause "New" or "Revised" License
Mesa llvmpipe	MIT License and Boost Software License 1.0
Notes about PDF Licensing	Details of restrictions on the use of PDF-related trademarks
The QtEntryPoint Library	Commercial and BSD 3-clause "New" or "Revised" License.
Trademarks	Information about trademarks owned by The Qt Company.

© 2023 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.