Qt 5.1 introduces many changes for helping developers continue creating wonderful applications, easily and with less code. As well in this release, focus is placed on bug fixing and new features, while maintaining compatibility with Qt 5.0.

This page is a summary of new features. For specific API changes, the List of API Changes section contains links to new and obsolete classes.

New Modules

New modules add more functionality for developers to use on various platforms.

• Qt Quick Controls - a set of reusable UI controls. Qt 5.1 targets desktop platforms, while future releases will include more features useful on touch devices.
• Qt Quick Layouts - provides layouts for Qt Quick
• Qt Quick Dialogs - contains types for creating and interacting with system dialogs
• Qt X11 Extras - adds platform specific APIs for X11
• Qt Sensors - provides access to sensor hardware and motion gesture recognition both via QML and C++ interfaces. Supports Android, BlackBerry, iOS, and Mer platforms.
• Qt Serial Port - provides an interface for hardware and virtual serial ports

The All Modules page contains a list of all modules in Qt 5.1.

New Supported Platforms

Qt 5.1 introduces support for following new platforms with technology preview status:

• Qt for Android (Technology Preview)
• Qt for iOS (Technology Preview)

Summary of Changes

moc Changes

• New keyword in Q_PROPERTY(), MEMBER, lets you bind a property to a class member without requiring to have a getter or a setter.

qmake Changes

• On Windows: Added support for specifying application icon (via RC_ICONS).

Qt Core Changes

• Added support for SHA3 to QCryptographicHash
• Added toInt(), toUInt(), and similar functions to QStringRef
• A new threadsafe initialization of global statics through refactored Q_GLOBAL_STATIC.
• A new class, QLockFile, provides locking between processes using a file. This lock enables applications to check that there is only one instance of it running.
• A new class, QSaveFile, provides transaction such as file writing.

Qt GUI Changes

• Support for embedding and reparenting of windows created from other processes, via QWindow::fromWinId().
• QWidget::createWindowContainer() adds the capability to embed QWindow instances, such as QQuickView or a QWindow using QOpenGLContext, into a QWidget hierarchy.
• Support for kerning advances in QRawFont::advancesForGlyphIndexes.
• QImageReader and QImageWriter adds the ability to report supported MimeTypes.
• New input method plugin, QComposeInputContext.
• New GTK+ 2.x platformtheme plugin that provides native file, font, and color dialogs.
• New class, QOpenGLContext::versionFunctions(), provides access to all OpenGL functions.
• New QOpenGLTimerQuery and QOpenGLTimeMonitor classes.
• New QOpenGLDebugLogger class expose KHR_debug extension for easy debugging.
• Added support for Geometry, Tessellation Control, Tessellation Evaluation, and Compute shaders to QOpenGLShader and QOpenGLShaderProgram.
• New QOpenGLVertexArrayObject class.

Qt Network Changes

• New encrypted() signal to QNetworkAccessManager and QNetworkReply so that applications can perform additional checks on the certificate chain.
• Support for sending intermediate certificates when QSslSocket is used as a server and when using client certificates.
• Support for SSL session reuse allowing much faster connections to servers.

Qt QML Changes

• New QQmlApplicationEngine convenience class for QML applications.
• New Instantiatior type for generic, dynamic object creation.
• New QtQml.Models module containing ListElement, ListModel, DelegateModel, DelegateModelGroup, and ObjectModel.
• New properties for Qt::application: arguments, name, and version.

Qt Quick Changes

• New threaded render loop for Mac, Linux, and Embedded.
• New render loop for windows for smoother animations.
• New Qt Quick Dialogs submodule with FileDialog and ColorDialog types.
• New Window properties: activeFocusItem, minimumWidth, minimumHeight, maximumWidth, maximumHeight, visibility, contentOrientation, and opacity.
• New Item property: activeFocusOnTab.
• New Grid properties: horizontalAlignment, verticalAlignment, and effectiveHorizontalAlignment.
• New TextEdit properties: selectByKeyboard and textDocument
• A Window declared inside another Window or Item will automatically be transient for (centered upon) the outer window.

Qt WebKit Changes

• JavaScript JIT on Windows 64 bit.
• Improved font rendering, kerning enabled by default.
• Improved garbage collection.
• Support for WOFF fonts.
• Support for WebGL without accelerated compositing.
• Support for GStreamer 1.0.
• Improved perceived page load performance and support for Link prefetch.

Qt Widgets Changes

• Added property toolTipsVisible in QMenu.

Qt Creator Compatibility

Qt Creator 2.7 complements this Qt release with the most prominent new features:

• Improved C++11 code editing support
• Qt Quick Designer with full support for Qt Quick
• Android development target
• Experimental QBS and diff integration

Other New Features

• Restored support for static Qt builds

List of API Changes

The pages below contain a list of API changes in Qt 5.1

• New Classes and Functions in Qt 5.1
• Obsolete Classes

Additions to Other Qt 5 Releases

• What's New in Qt 5.4
• What's New in Qt 5.3
• What's New in Qt 5.2
• What's New in Qt 5.0