Qt 6.12 was released on September 30 as a long-term support release with five years of maintenance. Qt matters well beyond its own developers: it is the toolkit under KDE Plasma and its applications, and under apps like VLC, Krita, OBS Studio, and the new Audacity 4.

QML Hot Reload

Developers can now see changes to a running QML interface as they edit the code, without restarting the application. It works through Qt Creator and the qmlpreview command-line tool. For interface work, cutting the edit, rebuild, relaunch, and navigate-back loop is a large productivity gain.

CanvasPainter is production-ready

CanvasPainter, an imperative drawing API accelerated through Qt’s Rendering Hardware Interface (which targets Vulkan, OpenGL, Metal, and Direct3D), graduates from Technology Preview in both C++ and QML. A new Canvas2D QML element modelled on the HTML canvas remains in preview.

Qt Graphs

Logarithmic axes, more axis-label customisation, built-in zoom and pan, and a CanvasPainter rendering backend for large datasets.

Also new

• StyleKit (Qt Labs): consistent styling across apps that mix Qt Widgets and Qt Quick, with light, dark, and high-contrast themes
• A QtQuick.Controls.Native style
• QRangeModel sorting, faster searching, and better drag and drop
• QtGrpc client-side compression and message size limits
• Better WebAssembly audio and video, and resource deduplication for smaller binaries
• HarmonyOS as an officially supported LTS platform

For Linux users

Applications move to new Qt versions gradually, and distributions ship Qt 6.12 on their own schedule: rolling distributions within weeks, LTS distributions in their next major release. Because 6.12 is an LTS, expect it to become the Qt version many distributions standardise on. KDE’s Plasma 6.8, due October 14, is the next big Qt-based release to watch.