What's New in Qt 6.8

New and Restored Modules in Qt 6.8

Qt 6.8 adds the following modules and tools:

• The svgtoqml tool, used to generate QML code from SVG documents, is now out of tech preview. The tool supports a static subset of the SVG Tiny 1.2 profile.
• The Qt Graphs, Qt HTTP Server, Qt Protobuf, and Qt GRPC modules are all promoted out of tech preview state.
• Added Qt Quick Vector Image module for displaying SVG documents as scalable vector graphics in a Qt Quick scene.

Removed Modules in Qt 6.8

The following module is deprecated. We strongly advise against using it in new code.

Qt 3D Module

The Qt 3D module is deprecated. Qt 3D remains part of the licensed software, and remains part of the Qt Project. The module continues to be integrated with other modules for future releases. Critical bugs and security vulnerabilities will be addressed by the module maintainers at KDAB. Regarding new features and functionality, users should contact KDAB by emailing info@kdab.com.

New Features in Qt 6.8

Qt Core Module

• QChronoTimer is a replacement for QTimer using std::chrono durations throughout.
• QTimer::id() returns a Qt::TimerId, introduced and accepted in place of int timer IDs in new overloads of various methods that take one.
• More support for std::chrono durations to replace integral nanosecond parameters in QAbstractEventDispatcher.
• QString, QByteArray, and QList gain resizeForOverwrite().
• QString, QByteArray gain slice() equivalent to *this = sliced().
• QString, QByteArray, QList, QVarLengthArray gain max_size() for compatibility with the Standard Template Library (STL).
• QList supports construction with uninitialized entries to a specified size, where the content-type permits.
• QVarLengthArray::PreallocatedSize tells you the Prealloc parameter.
• QLatin1StringMatcher::indexIn() can now take a QStringView.
• QCollatorSortKey now supports move-construction.
• QStringEncoder and QStringDecoder can now take the encoding name as a QString.
• QThread gains isMainThread(), isCurrentThread().
• QThreadPool::waitForDone() now accepts a QDeadlineTimer in place of int milliseconds.
• QDirListing provides stl-style iteration over directory entries.
• QVersionNumber can now be constructed from a QSpan; it can also be iterated over.
• qHash() now accepts quint128 and qint128.
• QMap::qHash() tells you a key's hash value.
• QHash can now hash different types from its key, if they are marked as having the equivalent hash result for equivalent values (C++20 only). This works for QString/QStringView and QByteArray/QByteArrayView pairs. On all systems except on ARM processors, the QLatin1StringView also participates in the QString and QStringView hashing.
• QPointF, QLineF, QRectF, and QMarginsF now support fuzzy comparison and null-checks.
• Define QT_ENABLE_STRICT_MODE_UP_TO to opt out of various APIs, documented by which version it cuts them out at.
• Define QT_NO_QASCONST to disable qAsConst().
• Define QT_(NO_)USE_NODISCARD_FILE_OPEN to control [[nodiscard]] on open() methods of I/O classes.
• QLibraryInfo::paths() returns all relevant paths.
• QCryptographicHash and QMessageAuthenticationCode gain hashInto() to compute the hash of data into a provided buffer.
• More QtCore types with operator<() now also support operator<=>() when compiled with C++20 (and compareThreeWay() even for C++17). These types now consistently support all six relational operators (as hidden friends) and the reverse of each mixed-type comparison they supported. At Qt 6.8, this applies to:
  • qfloat16
  • QAnyStringView
  • QByteArray
  • QByteArrayView
  • QCborArray
  • QCborMap
  • QCborValue
  • QChar
  • QDate
  • QDateTime
  • QDeadlineTimer
  • QElapsedTimer
  • QLatin1Char
  • QLatin1StringView
  • QModelIndex
  • QOperatingSystemVersion
  • QPersistentModelIndex
  • QString
  • QStringView
  • QTime
  • QTypeRevision
  • QUrl
  • QUtf8StringView
  • QUuid
  • QVersionNumber
• The QtJniTypes namespace, with macros to declare Java types with their JNI signature, is promoted out of technology preview and documented.
• The variadic template versions of QJniObject and QJniEnvironment APIs are no longer preliminary and fully documented.
• The new QJniArray template class makes it easy to work with Java arrays from C++ code.

Qt Graphs Module

• Qt Graphs is promoted out of tech preview.
• The module is split into two submodules, Qt Graphs and Qt Graphs Widgets, to remove the requirement for including widgets into pure QML applications.
• Unified theming for 2D and 3D graphs. See GraphsTheme.
• See migration guides from Qt Charts and from Qt DataVisualization.

Qt Graphs3D

• Added transparency support for Bars3D and Scatter3D.
• Added support for Scene3D.primarySubViewport and Scene3D.secondarySubViewport.
• Added support for offsetting graph titles' position . See Abstract3DAxis.titleOffset.
• Added support for label margins. See GraphsItem3D.labelMargin.
• Added support for rendering the grid with a shader and changing the gridline width. See GraphsItem3D.gridLineType and GraphsTheme.GraphsLine.mainWidth.

Qt Graphs2D

• Added support for AreaSeries.
• Added support for custom bars using QML components. See BarSeries.barDelegate.
• Added support for Stacked and StackedPercent bars. See BarSeries.barsType.
• Added support for bar graph labels. See BarSeries.labelsVisible.
• Added model mappers support for different series. See XYModelMapper, BarModelMapper and PieModelMapper.
• Added LegendData support for all series.
• Added support for dynamic splineseries.
• Added support for axis titles. See AbstractAxis.titleText.

Qt GRPC Module

• Qt GRPC is promoted out of tech preview.
• Added streaming support to the GrpcQuick module.
• Removed QGrpcInterceptor, QGrpcInterceptorManager and QGrpcInterceptorContinuation.
• Added the writesDone() method to QGrpcClientStream and QGrpcBidirStream to half-close a stream from the client side.

Qt GUI Module

• QStyleHints::colorScheme now has a setter function that allows applications to try to override the system setting with an explicit Dark or Light scheme.
• Added QFont::ContextFontMerging, which can be used to enable a new font merging algorithm that takes the full string into account when selecting fallback fonts. This may come at some more cost, but in certain cases, it will give better results.
• Added QFont::PreferTypoLineMetrics style strategy, which can be set to always prefer the typographical line metrics in OpenType fonts, even if the font does not manually set the USE_TYPO_METRICS flag.
• Added QDesktopServices custom and https URL scheme support for macOS, similar to what iOS has.
• QImage::Format_CMYK8888 32bit CMYK image format has been added.
• QColorSpace support for ICC A2B color spaces processing has been added, along with explicit support for grayscale and CMYK color spaces.
• Added support for QColorSpace::Bt2020, QColorSpace::Bt2100Pq, and QColorSpace::Bt2100Hlg HDR color spaces.
• QColorSpace::transformModel() returns the underlying processing model.
• QColorSpace::colorModel() returns which color model the color space is made for.
• QImage::colorTransformed() and QImage::applyColorTransform() variants with three arguments has been added to support converting both image format and color space at the same time.
• QStyleHints::contextMenuTrigger is a writable property that allows applications to control whether context menus should be opened via button press or release.
• Qt Accessibility interfaces now can support reporting of attributes as key/value pairs to clients.
• QAccessibleAnnouncementEvent can be raised by applications to request the announcement of a message by assistive technologies.
• QPageLayout::setMargins now can take an optional OutOfBoundsPolicy parameter to indicate whether margins that are out of bounds should be rejected or clamped.
• QPdfWriter gained CMYK support for pens/fills.
• QFontDatabase gained addApplicationFallbackFontFamily to specify the override default fallback font families for specific scripts.
• Completed multiview rendering support in QRhi. Multiview is now also supported with Vulkan 1.1 implementations, instead of requiring Vulkan 1.2. This is relevant in particular for Android-based devices such as the Meta Quest 3.
• Introduced QRhi support for automatically resolving multisample depth (depth/stencil) rendering into a non-multisample depth (depth/stencil) texture, on platforms and APIs where this can be supported. See QRhiTextureRenderTargetDescription::setDepthResolveTexture() and QRhi::ResolveDepthStencil for details.

Qt Multimedia Module

• Added the classes QVideoFrameInput and QAudioBufferInput, which can send custom media data to QMediaRecorder through QMediaCaptureSession.
• Added the class QAudioBufferOutput, which can receive decoded audio data from QMediaPlayer.
• Added the class QAbstractVideoBuffer, allowing the creation of QVideoFrame instances with custom video data.
• QMediaRecorder can write the media output to QIODevice.
• Added support of QScreenCapture on Linux using the Wayland compositor, which supports the ScreenCast service via XDG Desktop Portal.
• The FFmpeg library is dynamically linked to the FFmpeg plugin, and the utilized shared FFmpeg modules are shipped with Qt Multimedia.
• Added support for the FFmpeg media backend on iOS.
• Bumped the minimum required GStreamer version to 1.20.

Qt Network Module

• QNetworkAccessManager gained support for sending HTTP requests over a local socket using the unix+http: or local+http: scheme.
• QDnsLookup now supports sending DNS over TLS and can inform whether the DNS server has performed verification on data authenticity.
• QDnsLookup gained support for TLS Association records.
• QNetworkCacheMetaData, QNetworkProxy, QNetworkRequest, and QNetworkReply can now get and set headers.
• QNetworkRequestFactory allows setting the priority as well as attributes for future requests.
• Added classes QFormDataPartBuilder and QFormDataBuilder to ease the creation of QHttpMultipart messages.

Qt Network Auth Module

• Added QOAuthUriSchemeReplyHandler class, which handles private/custom and https URI scheme redirects (supported platforms: iOS, Android, and macOS).
• Added Proof of Key Code Exchange (PKCE) support to the QOAuth2AuthorizationCodeFlow class. PKCE is a recommended security measure to mitigate authorization code interception attacks.
• Following input from several users we went back and addressed many issues with the aim to generally improve qnetworkauth. This includes several bug fixes, improvements, deprecations, documentation additions, and also an overview documentation to help with getting started.

Qt Positioning Module

• The Qt Positioning Android backend can now provide altitude in MSL format on Android 14 and later.

Qt Protobuf Module

• The Qt Protobuf module is promoted out of tech preview.

Qt QML Module

• Added new features to QML Language Server: semantic highlighting, more JavaScript language support, snippet support for Quick types, documentation hints, QML file renaming, .qmllint.ini warning configuration support
• Two new CMake Policies affecting the behavior of qt_add_qml_module have been added: QTP0004 eases the use of QML modules when nested folder structures are used. QTP0005 allows the usage of targets when specifying imports and dependencies.

Qt Quick Compiler

• The Qml Script Compiler now records statistics about Qml to Cpp compilation. This information can be displayed by running the all_aotstats target on the project.

Qt Quick Module

• Added font.contextFontMerging, which can be used to enable a new font merging algorithm that takes the full text into account when selecting fallback fonts. This may come at some more cost, but in certain cases it will give better results.
• Added font.preferTypoLineMetrics property, which can be set to always prefer the typographical line metrics in OpenType fonts, even if the font does not manually set the USE_TYPO_METRICS flag.
• Added the retainWhileLoading property to Image and BorderImage. When set to true on images that load asynchronously, the current image data will be retained until the new image is fully loaded. This can avoid flickering.
• Added PlanarTransform, a utility object providing simple functions for specifying 2D transformation matrices.
• Added PathRectangle, an optionally rounded rectangle path for Shape and PathView.
• Added the Drag.imageSourceSize property to control the size of the image representing the data being dragged.
• Added QQuickRenderTarget::depthTexture as a way to set a custom depth texture.
• Added QQuickRenderTarget::Flag enumerator to allow specifying a view format when constructing through the named constructors.
• TableView now has support for programmatically and interactively moving columns and rows.
• All standard Qt Quick items and materials are made compatible with Multiview Rendering. This is utilized transparently to the applications when 2D content is embedded into an Qt Quick 3D XR scene and multiview rendering is enabled. Multiview rendering can improve rendering performance and decrease power consumption of AR/VR devices.
• Creating multiview-compatible custom materials (QSGMaterial, QSGMaterialShader) is made possible via QSGMaterial::viewCount().
• Added support for directing Qt Quick rendering into a 2D texture array with Multiview Rendering in QQuickRenderTarget. This is realized via new overloads of functions such as QQuickRenderTarget::fromVulkanImage(), and forms the foundation of multiview rendering support for XR applications built with Qt Quick 3D.
• Added support for automatically performing multisample resolve at the end of a render pass in QQuickRenderTarget. Previously multisample rendering of redirected Qt Quick scenes was only possible by targeting multisample textures, leaving resolving up to the application or its shaders. When enabled, Qt Quick will now automatically create intermediate, multisample textures for use as a color buffer, performing the resolve into the application-provided non-multisample texture automatically. This allows making Qt Quick rendering target textures provided by an external engine, framework, or API (e.g., OpenXR) that only provides and consumes non-multisample textures.
• Added support for setting a depth texture in QQuickRenderTarget. This allows specifying the application's own texture (or texture array, when using multiview rendering) where depth data is written, instead of using Qt's own intermediate buffers. Useful in particular when depth data must be written to a depth texture provided by an external engine, framework, or API (e.g., OpenXR).
• Added support for specifying a texture view format in QQuickRenderTarget. This is specified via the viewFormat argument in the new overloads for QQuickRenderTarget::fromVulkanImage() and similar. This feature is provided specifically to allow dropping or adding the sRGB qualifier from or to the texture format, and is useful when having to work with textures provided by an external engine, framework, or XR compositor, where control over the texture format is not available, yet the 3D APIs' implicit linear->sRGB conversion on shader writes is not acceptable (e.g., because the Qt Quick 3D material pipeline already performs the same operation).
• QQuickRenderTarget's internal management of intermediate buffers for depth/stencil and multisample color data has been redesigned. Calling QQuickWindow::setRenderTarget() no longer invalidates all internal temporary buffers, but rather attempts reuse as long as the size, format, and other parameters match. This is expected to lead to performance improvements in applications and libraries that have to pass in a different native texture to the QQuickWindow on every frame (e.g, because the texture comes from a buffer pool maintained by an external engine, framework, or XR compositor).

Qt Quick Controls Module

• Added FluentWinUI3 Style, a modern native-looking style designed for platforms running Windows 11 and above.
• Added a new property popupType to Popup, and derived types. This can be used to control whether the popup should be in-scene, or appear in its own top-level popup window.
• The macOS style is now capable of creating native menus and menubars.

Qt Quick Shapes Module

• Added the ShapePath.fillItem property. This can be used to take any texture provider item (such as layered items and images) and use them as fill for the shape.
• Added the ShapePath.fillTransform property, which can be used to set an arbitrary transform on the shape's fill, whether it is an item or a gradient.

Qt Quick 3D Module

• Technology Preview of XR support for Qt Quick 3D
  • Support for Head Mounted Displays (HMD) using OpenXR such as the Meta Quest 2 and 3.
  • Support for Apple Vision Pro.
  • Multi-view rendering (render both eyes in a single pass).
  • Spatial input support via hand tracking or controllers.
  • Support for spatial anchors.
• Improved Shadow Rendering
  • Overall quality improvements.
  • Enhanced shadow debug tooling.
  • Cascading Shadow Maps.
  • Percentage-closer filtering (PCF) soft shadows.
• PrincipledMaterial Enhancements
  • Additional parameters for adjusting Fresnel.
  • Support for property masking based on the vertex color attribute.
• CustomMaterial: expose remaining properties from PrincipledMaterial.

Qt Quick VectorImage Module

• Introduced the VectorImage: A component which can be used to render vector graphics directly Qt Quick with hardware acceleration and no pre-rasterization. It currently supports the SVG format (a static subset of the SVG Tiny 1.2 profile.)

Qt Shader Tools Module

• Completed support for shaders compatible with multiview rendering. Added the MULTIVIEW keyword to the Qt Shader Tools Build System Integration.
• Added depfile support for shaders processed at build time via qt_add_shaders(). Touching a file included via the #include directive in a shader will now trigger a recompilation of that shader file when building the project the next time.

Qt Sql Module

• QSqlDatabase, QSqlQuery, and QSqlDriver gained numericalPrecisionPolicy.
• QSqlDatabase got a new function moveToThread() to change the thread affinity of the database connection.
• The PostgreSQL and MySQL/MariaDB drivers now correctly handle dates/times when the server is in a different timezone than the client.
• All logging is now done through categorized loggers, qt.sql, to improve debugging.
• QSqlField::defaultValue, value, readOnly, requiredStatus, length, precision, generated, autoValue, and tableName are now properties.
• QSqlIndex::name and cursorName, QSqlQuery::forwardOnly, and positionalBindingEnabled are now properties.

Qt Test Module

• Added QTEST_THROW_ON_FAIL and QTEST_THROW_ON_SKIP C++ macros and environment variables that, when defined, change how QCOMPARE()/QVERIFY()/QSKIP() etc exit the test function on failure. Instead of a return, exiting only the immediately-surrounding function, they throw a special exception instead, thereby exiting from sub-functions of the test function, all the way to QtTestLib.
• The QTRY_*_WITH_TIMEOUT macros now also accept chrono literals (was: int milliseconds).
• QTest::failOnWarning() now has a no-parameter overload to support the common case of fail-on-any-warning, without needing to construct a match-everything regular expression.
• QSignalSpy no longer inherits from QObject. If your code uses the fact that QSignalSpy is-a QObject, you need to redesign around this now.
• The QSignalSpy::signal() method no longer necessarily returns an empty byte array when the connection failed. Use the existing isValid() method to determine whether a given QSignalSpy object listens to a valid signal on a valid object.
• The QCOMPARE_xx macros can now only find QTest::toString() expansions that are either found via Argument Dependent Lookup on the type in question or are an instantiation of the QTest::toString<T>() template. This matches the behavior of the QCOMPARE() macro.

Qt WebEngine Module

• QWebEngineFrame added for frame specific API, such as running javascript on specific frames, or printing specific frames.
• QWebEngineClientHints added to better control the browser identification to web pages using client hints DOM api.
• QWebEnginePermission added to manage new and existing website permissions. The existing permissions API in QWebEnginePage has been deprecated, and replaced by QWebEngineProfile::getPermission() and QWebEngineProfile::listPermissions()
• Added QWebEngineProfile::setPersistentPermissionsPolicy() to control how website permissions persist across browsing sessions. By default, incoming permissions are saved to disk.
• Added QWebEnginePermission::ClipboardReadWrite and QWebEnginePermission::LocalFontsAccess permission types.
• QWebEngineCertificateError::isMainFrame() indicates the certificate error is from a main or sub frame.
• QWebEngineNavigationRequest::hasFormData() added to indicate a navigation request sending form data.
• QWebEngineSettings::imageAnimationPolicy() added to control image animation policy.

Tools

QDoc Documentation Generator

• You can now use the \keyword command to link to a section title, as a means to improve context sensitive help.
• QDoc no longer incorrectly links to non-existing documentation for undocumented property access functions.
• The build system no longer defines QDOC2_COMPAT.
• When generating DocBook output, QDoc no longer escapes characters multiple times.
• The \instantiates command is deprecated. Use the new \nativetype command instead. The old command now delegates to the new one, and QDoc generates a notice about its deprecation.
• You can specify auto as return type for functions as a way to mask the full type in the generated documentation.
• Improved formatting of the requisites table in API documentation.
• QDoc generates less duplicate reports in its output to stdout.
• .qhp files now (correctly) contain entries for group items created with the \ingroup command when there is no related \group documentation.
• QDoc now generates titles for namespaces in .qhp files, not just for classes and types.
• QDoc now correctly parses -DDEFINE=VALUE command line options.
• QDoc generates new warnings if:
  • qhp subproject indexTitle attribute isn't found.
  • If the \nativetype command is used multiple times for the same C++ class.
  • When generating a file multiple times per project.
  • Functions previously selected as an overload that aren't explicitly marked with the \overload command, that due to sorting changes are selected as the primary signature. They must either be documented in full or tagged with the \overload command.
• QDoc no longer warns about undocumented parameters in overloaded constructors, and some unnecessary link warnings were removed.
• Link warnings now report sensible locations.
• QDoc now requires Clang 17 or newer.
• The QDoc manual received multiple updates.
• You can tag trademarks with the new \tm command. If you define the configuration variable navigation.trademarkspage, the trademark symbol (tm) becomes a link to that page.
• The \deprecated command now accepts future versions.
• QDoc macro arguments now accept formatting commands.
• The \compareswith command now allows for brace-enclosed arguments.
• The -outputdir command-line option is now relative to the current working directory. Also, the nosubdirs configuration variable no longer mangles what is in outputdir.
• The unused and undocumented clangdefines configuration variable is removed.
• QDoc no longer generates .qhp.sha1 files.
• QDoc now generates unique references to entries in the table of contents.
• When generating HTML output, QDoc now only decorates links to API entities with translate="no".
• Name collisions for multi-project documentation builds have been reduced. This may impact the generated file names in certain configurations.
• CMake targets can now be specified with the new \qtcmaketargetitem command.
• Support for subscripted function arguments has been removed. This feature was undocumented, unused, and bug-ridden. Its removal saves the construction and attempted matching of regular expressions on every single documented function signature and \a command argument.
• Links to function signatures are now more consistent in appearance.
• QDoc now supports auto-generated values in QML documentation from C++ enums.
• The outputprefixes and outputsuffixes configuration variables now apply to C++ type documentation as well as to QML type and module documentation. This can be convenient in multi-module documentation configurations where two or more modules define the same type names.

Platform Changes

Desktop Platforms

Windows

• Changed the font system to use DirectWrite as the default backend. This enables some modern features which were not available with the legacy GDI backend. The previous backend is still available and can be enabled by passing fontengine=gdi as parameter to the QPA plugin.

macOS

• Added support for macOS 15
• Added support for safe area margins, both for the camera notch in full screen applications, and for windows where the contents extends into the titlebar.
• Fixed flicker when resizing Qt Quick windows, by presenting Metal layer with transaction.
• Enabled running animations when resizing Qt Quick windows.
• Adopted new NSCursor API for window frame resize cursors
• Implemented NSServicesMenuRequestor protocol for Services menu and Writing Tools support.

Wayland Client on Linux

• Added a new window decoration style that is used on GNOME and uses similar styling as GNOME.
• Modal status of dialogs is now forwarded to the compositor via the new xdg-dialog-v1 protocol.
• Showing a window will now also request activation from the compositor (except when Qt::WA_ShowWithoutActivating is set).
• Added support to qtwaylandscanner to send null for null QString.
• Added options PUBLIC_CODE and PRIVATE_CODE to qt6_generate_wayland_protocol_client_sources that control the options that are passed to wayland-scanner.
• Implemented the screen capture feature using ScreenCast service via XDG Desktop Portal in Qt Multimedia.

Mobile Platforms

Android

• Bumped the minimum supported version to Android 9.
• Added support for build.gradle namespace property.
• Added a CMake property QT_ANDROID_PACKAGE_NAME to set the package name.
• Updated Gradle to 8.10 and AGP to 8.6.0.
• Added support for building AAR library packages.
• Deprecated the native Android backend in Qt Multimedia.
• When opening libraries with QLibrary, JNI_OnLoad is no longer called by default.
• QtQuickView and QML Embedding:
  • Added strong typing support for QtQuickView API.
  • Added API to manage QML content, under this Java classes under QtQuickView were moved to own classes. This includes:
    • QtQuickView.SignalListener to QtSignalListener.
    • QtQuickView.StatusChangeListener to QtQmlStatusChangeListener.
    • QtQuickView Status to QtQmlStatus.
  • Added Java classes QtAbstractItemModel, QtAbstractListModel, and QtModelIndex, that wraps QAbstractItemModel, QAbstractListModel, and QModelIndex, respectively.
  • Added support for QML embedding from a Service.

iOS

• Added support for iOS 18
• Fixed wrongly reporting UIDevice.currentDevice.orientation via QScreen::orientation()
• Improved accessibility integration.

visionOS

• Added preliminary support for visionOS.

Embedded Platforms

QNX

• Added QNX 8.0 support as Technology Preview.
• QNX 8.0 doesn't have multimedia support, use -skip qtmultimedia on configure.

VxWorks

• Added VxWorks 24.03 support.

List of API Changes

These pages contain an overview of API changes in Qt 6.8:

• New Classes and Functions in Qt 6.8
• Obsolete Classes