Third-Party Code Used in Qt

Qt libraries and plugins can contain code that is not intellectual property of The Qt Company, but is available under specific open-source 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 acknowledge and comply with the licenses of the third-party components that you are actually shipping with your application. Click the name of the component to see the licensing details.

Third-party Licenses

The following sections list third-party components in Qt 6.11.0, grouped by Qt module. If the third-party component itself consists of parts that are of a different origin (so-called 4th-party or Nth-party code), these are listed, too.

Starting from Qt 6.8, Software Bill of Materials (SBOM) documents of third-party components in Qt are available. Information such as copyrights, licenses, versions, source repositories, and other relevant information are declared in SPDX 2.3 format. For more information, visit the Software Bill of Materials page.

Qt 3D

Dear ImGui - ProggyClean.ttf	MIT License
Dear ImGui - stb	MIT License or Public Domain
Dear ImGui, version v1.91.0	MIT License
Open Asset Import Library, version 6.0.2	BSD 3-clause "New" or "Revised" Licensee

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

Apache Tika MimeType Definitions, version dbcbb368e0a913e1a74cca61347fd6ce24bc6d7e	Apache License 2.0
BLAKE2 (reference implementation), version ed1974ea83433eba7b2d95c5dcd9ac33cb847913	Creative Commons Zero v1.0 Universal or Apache License 2.0
Data Compression Library (zlib), version 1.3.1	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 3.3.1	BSD 3-clause "New" or "Revised" License
MD4	Public Domain
MD5	Public Domain
PCRE2 - Stack-less Just-In-Time Compiler, version 10.46	BSD 2-clause "Simplified" License
PCRE2, version 10.46	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 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 0.6.1	MIT License
Unicode Character Database (UCD), version 34	Unicode License Agreement - Data Files and Software (2016)
Unicode Common Locale Data Repository (CLDR), version v47	Unicode License v3
forkfd	MIT License
tl::expected, version 41d3e1f48d682992a2230b2a715bca38b848b269	Creative Commons Zero v1.0 Universal

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
Cocoa Platform Plugin	BSD 3-clause "New" or "Revised" License
D3D12 Memory Allocator, version f128d39b7a95b4235bd228d231646278dc6c24b2	MIT License
DejaVu Fonts, version 2.37	Bitstream Vera Font License
Emoji Segmenter, version 0.4.0	Apache License 2.0
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 2.13.3	Freetype Project License or GNU General Public License v2.0 only
HarfBuzz-NG, version 11.4.1	MIT License
LibJPEG-turbo, version 3.1.1	Independent JPEG Group License and BSD 3-Clause "New" or "Revised" License
LibPNG, version 1.6.50	Libpng License and PNG Reference Library version 2
MD4C, version 0.5.2	MIT License
Mipmap generator for D3D12, version 0aa79bad78992da0b6a8279ddb9002c1753cb849	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 1.4.308	Apache License 2.0 or MIT License
Vulkan Memory Allocator, version 3.2.1	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 4.7.0	Libtiff License
WebP (libwebp), version 1.6.0	BSD 3-clause "New" or "Revised" License

Qt Multimedia

DR Libs, version 0.13.17	MIT No Attribution
FFmpeg, version 7.1.1	GNU Lesser General Public License v2.1 or later and BSD 3-Clause "New" or "Revised" License and BSD 2-Clause "Simplified" License and BSD Source Code Attribution and ISC License and MIT License and Mozilla Public License 2.0
Signalsmith Stretch, version 1.0.0	MIT License
Two-Level Segregated Fit, version v3.1	BSD 3-Clause "New" or "Revised" License
boost	Boost Software License 1.0
libjpeg	Independent JPEG Group License
zlib	Zlib License

Qt Network

The Public Suffix List, version 2025-06-16_09-45-02_UTC	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 1.4.13

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

Qt PDF

Abseil	Apache-2.0
FreeType	FTL
PDFium	BSD
The Chromium Project	BSD 3-clause "New" or "Revised" License
fast_float	MIT
harfbuzz-ng	MIT-Modern-Variant
icu	MIT
libjpeg-turbo	IJG, BSD-3, Zlib
libpng	Libpng-2.0, Libpng
zlib	Zlib

Qt Positioning

Clip2Tri Polygon Triangulation Library, version commit f62a734d22733814b8a970ed8a68a4d94c24fa5f	MIT License
Clipper Polygon Clipping Library, version 6.4.2	Boost Software License 1.0
Poly2Tri Polygon Triangulation Library, version commit a922022da4c0d3a55b1d6b6d634219caea653053	BSD 3-clause "New" or "Revised" License

Qt Qml

JavaScriptCore Macro Assembler

BSD 2-clause "Simplified" License

Qt Quick

Yoga, version 2.0.1

MIT License

Qt Quick 3D

Godot Engine: Fog	MIT License
Godot Engine: ProceduralSky	MIT License
Intel Embree, version 3.13.3	Apache License 2.0
Java Native Interface for C++, version 1.0.0	MIT License
JsonCpp, version 1.9.6	MIT License
Open Asset Import Library, version 6.0.2	BSD 3-clause "New" or "Revised" Licensee
OpenXR SDK, version 1.1.49	Apache License 2.0
Tiny OpenEXR, version 1.0.12	BSD 3-clause "New" or "Revised" License
meshoptimizer, version 0.23	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 3.50.4

SQLite Blessing

Qt SVG

XSVG	Historical Permission Notice and Disclaimer - sell variant

Qt Sensors

Android getRotationMatrix and getOrientation

Apache License 2.0

Qt Shader Tools

SPIRV-Cross, version 1a69a919fa302e92b337594bd0a8aaea61037d91	Apache License 2.0 and MIT Khronos - old variant
glslang, version 15.1.0	BSD 3-Clause "New" or "Revised" License, and MIT Khronos - old variant, and Apache License 2.0, and GNU General Public License v3.0 or later with Bison exception 2.2, and AML glslang variant License

Qt Spatial Audio

Eigen, version 3.4.0	Mozilla Public License 2.0 and BSD 3-Clause "New" or "Revised" License
Resonance Audio, version e225aedb5ec76ca6a0fe7079c0b84dbcbb490553	Apache License 2.0
pffft, version 02fe7715a5bf8bfd914681c53429600f94e0f536	BSD 3-Clause "New" or "Revised" License

Qt Test

Catch2, version 2.13.10	Boost Software License 1.0
Cycle, version 3.3.10	MIT License
Linux Performance Events, version 6.13	GNU General Public License v2.0 only with Linux Syscall Note
Valgrind, version 3.25.1	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

Wayland IVI Extension Protocol, version 1.9.1

MIT License

Qt WebEngine

@puppeteer/replay	Apache-2.0
@vscode/web-custom-data	MIT
AXE-CORE Accessibility Audit	MPL 2.0
Abseil	Apache-2.0
Abseil	Apache-2.0
Acorn, a tiny, fast JavaScript parser written in JavaScript.	MIT
Alliance for Open Media Video Codec	BSD-2-Clause, Patent
Alliance for Open Media Video Codec	BSD-2-Clause, Patent
Almost Native Graphics Layer Engine	BSD
Android Explicit Synchronization	Apache-2.0
Android Explicit Synchronization	Apache-2.0
BoringSSL	MIT, BSD-3-Clause, OpenSSL, ISC, SSLeay
BoringSSL	MIT, BSD-3-Clause, OpenSSL, ISC, SSLeay
Brotli	MIT
Brotli	MIT
C++ Signal/Slot Library	Ignorable
C++ Signal/Slot Library	Ignorable
CRC32C	BSD-3-Clause
CRC32C	BSD-3-Clause
CSP Evaluator Core Library, a tool that allows developers to check if a Content Security Policy (CSP) serves as mitigation against XSS attacks	Apache
Chromium License	BSD
CityHash	MIT
CityHash	MIT
CodeMirror 5	MIT
CodeMirror 6	MIT
Compact Encoding Detection	Apache-2.0
Compact Encoding Detection	Apache-2.0
Compact Language Detector v3	Apache-2.0
Crashpad	Apache-2.0
Crashpad	Apache-2.0
Dawn	BSD 3-Clause
Devtools-Frontend	BSD-3-Clause
Emoji Segmenter	Apache-2.0
Expat XML Parser	MIT
Expat XML Parser	MIT
FP16	MIT
Fiat-Crypto: Synthesizing Correct-by-Construction Code for Cryptographic Primitives	Apache 2.0
Fiat-Crypto: Synthesizing Correct-by-Construction Code for Cryptographic Primitives	Apache 2.0
FlatBuffers	Apache-2.0
General Purpose FFT (Fast Fourier/Cosine/Sine Transform) Package	Custome license
General Purpose FFT (Fast Fourier/Cosine/Sine Transform) Package	Custome license
Google Double Conversion	BSD-3-Clause
Google Double Conversion	BSD-3-Clause
Headers for the Windows 10 WebAuthn API (webauthn.dll)	MIT
Highway: C++ library for SIMD	Apache-2.0
Implementation of WebDriver BiDi standard	Apache 2.0
Ink	Apache-2.0
Ink Stroke Modeler	Apache-2.0
LevelDB: A Fast Persistent Key-Value Store	BSD-3-Clause
Libtess2	SGI Free Software License B
Lighthouse	Apache License 2.0
Lighthouse i18n.js	Apache License 2.0
Lit	BSD-3-Clause
Lit	BSD-3
Lit	BSD-3-Clause
Lit	BSD-3
Lit	BSD-3-Clause
Marked	MIT
Material color utilities	Apache-2.0
Metrics Protos	BSD-3-Clause
Metrics Protos	BSD-3-Clause
NVidia Control X Extension Library	MIT
OTS (OpenType Sanitizer)	BSD-3-Clause
One Euro Filter	BSD-3-Clause
PDFium	BSD
PFFFT: a pretty fast FFT.	Pffft
PFFFT: a pretty fast FFT.	Pffft
PSM (Private Set Membership) client side	Apache-2.0
Paul Hsieh's SuperFastHash	BSD-3-Clause
Paul Hsieh's SuperFastHash	BSD-3-Clause
Perfetto	Apache2
Perfetto	Apache2
Polymer	BSD-3-Clause
Polymer	BSD-3-Clause
Protocol Buffers	BSD-3-Clause
Protocol Buffers	BSD-3-Clause
Protocol Buffers (javascript)	BSD-3-Clause
Protocol Buffers (javascript)	BSD-3-Clause
Puppeteer Core	Apache-2.0
QUICHE	BSD-3-Clause
QUICHE	BSD-3-Clause
Recurrent neural network for audio noise reduction	BSD-3-Clause
Recurrent neural network for audio noise reduction	BSD-3-Clause
SPIR-V Headers	Apache-2.0
SPIR-V Tools	Apache-2.0
Search Engines resources	BSD-3-Clause
Selenium Atoms	Apache-2.0
Simple Homomorphic Encryption Library with Lattices	Apache-2.0
Sizzle	MIT
Snappy: A fast compressor/decompressor	BSD-3-Clause, CC-BY-4.0, MIT, CC-BY-3.0
Speech Dispatcher	LGPL-2.1
The Chromium Project	BSD 3-clause "New" or "Revised" License
The Chromium Project	BSD 3-clause "New" or "Revised" License
The Diff Match and Patch libraries offer robust algorithms to perform the operations required for synchronizing plain text.	Apache License 2.0
The Incremental Distributed Point Functions library	Apache-2.0
URI Template Parser	Apache-2.0
URI Template Parser	Apache-2.0
URL Pattern Library	MIT
URL Pattern Library	MIT
V8 fork of fdlibm	SunPro
Volk Meta loader for Vulkan API	MIT
Vulkan API headers	Apache-2.0
Vulkan API headers	Apache-2.0
Vulkan Loader Components	Apache-2.0
VulkanMemoryAllocator	MIT
Wasmparser	Apache
Web Vitals	Apache
WebKit	BSD and LGPL v2 and LGPL v2.1
WebKit	BSD and LGPL v2 and LGPL v2.1
WebM container parser and writer.	BSD-3-Clause, Patent
WebP image encoder/decoder	BSD-3-Clause, Patent
WebP image encoder/decoder	BSD-3-Clause, Patent
WebRTC	BSD
WebRTC	BSD
Wicked Good XPath	MIT
Wuffs (Wrangling Untrusted File Formats Safely)	Apache-2.0
Wuffs (Wrangling Untrusted File Formats Safely)	Apache-2.0
Zstandard	BSD-3-Clause
Zstandard	BSD-3-Clause
cpuinfo	BSD-2-Clause
d3	ISC
d3	ISC
dav1d is an AV1 decoder :)	BSD-2-Clause
dav1d is an AV1 decoder :)	BSD-2-Clause
fast_float	MIT
ffmpeg	LGPL 2.1
fft	Custom license
fft	Custom license
flac	BSD
fontconfig	Public-domain-md5, MIT-Modern-Variant, HPND-sell-variant, MIT
fontconfig	Public-domain-md5, MIT-Modern-Variant, HPND-sell-variant, MIT
google-glog's symbolization library	BSD-3-Clause
google-glog's symbolization library	BSD-3-Clause
harfbuzz-ng	MIT-Modern-Variant
harfbuzz-ng	MIT-Modern-Variant
hunspell	MPL-1.1
icu	MIT
icu	MIT
inspector protocol	BSD-3-Clause
inspector protocol	BSD
inspector protocol	BSD
inspector protocol	BSD-3-Clause
intl-messageformat	New BSD
ipcz	BSD
ipcz	BSD
json5	MIT
jsoncpp	JsonCPP
jsoncpp	JsonCPP
libaddressinput	Apache-2.0
libavif - Library for encoding and decoding .avif files	BSD-2-Clause, MIT
libgav1	Apache-2.0
libpng	Libpng-2.0, Libpng
libpng	Libpng-2.0, Libpng
libsrtp	3-clause BSD
libsrtp	3-clause BSD
libvpx	BSD-3-Clause, Patent
libvpx	BSD-3-Clause, Patent
libxml	MIT
libxslt	X11
libyuv	BSD
libyuv	BSD
mesa_headers	MIT, SGI-B-2.0
minigbm	BSD-3-Clause
mitt	MIT
modp base64 decoder	BSD-3-Clause
modp base64 decoder	BSD-3-Clause
opus	Opus-Patent-BSD-3-Clause
opus	Opus-Patent-BSD-3-Clause
rapidhash	BSD-2-Clause
re2 - an efficient, principled regular expression library	BSD-3-Clause
re2 - an efficient, principled regular expression library	BSD-3-Clause
simdutf unicode transcoder	MIT
simdutf unicode transcoder	MIT
spl sqrt floor	SPL-SQRT-FLOOR
spl sqrt floor	SPL-SQRT-FLOOR
sqlite	Blessing
sqlite	Blessing
third-party-web	MIT
woff2	MIT
xdg-user-dirs	MIT
xdg-user-dirs	MIT
zlib	Zlib
zlib	Zlib
zod	MIT

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
Software Bill of Materials	Qt package information in SPDX format
The QtEntryPoint Library	Commercial and BSD 3-clause "New" or "Revised" License.
Trademarks	Information about trademarks owned by The Qt Company.

Qt Licensing License of Qt examples

© 2025 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.