The QGIS project has announced significant changes to its platform that will be implemented over the coming months. These modifications are part of a long-planned technical migration that will bring new possibilities and ensure QGIS remains modern, fast, and future-ready.
Migration to Qt6
QGIS is migrating to Qt6, the latest version of the cross-platform application framework upon which it is built. This update will allow:
- Future-proofing of the QGIS codebase
- Taking advantage of modern libraries with significant performance and security improvements
- Simplifying long-term maintenance and development
While most of the migration is complete, a few tasks remain, especially around Continuous Integration, layout rendering, and PDF output. The core team is actively working on these aspects and making significant progress.
QGIS 4.0
To mark this significant change in infrastructure, the project has decided to align the Qt6 migration with a new major release: QGIS 4.0, which will arrive after QGIS 3.44, in October 2025.
Key aspects to consider:
- QGIS 4.0 will function exclusively with Qt6
- It will not be an LTR (Long-Term Release) version
- To ease the transition, it will retain deprecated APIs, which means plugin developers will only need minimal work to ensure compatibility with Qt6 and prepare for future versions
This strategy allows modernizing QGIS without forcing a complete rewrite of existing plugins, though some adjustments will be necessary to ensure compatibility with QGIS 4.0.
Importance of the Update
This migration isn’t just about upgrading for the sake of it—it’s about keeping QGIS secure, modern, and maintainable:
- Qt 5.15 enters Extended Support (EOS) in May 2025, with continued security updates available only under commercial terms
- Staying on Qt5 would limit access to upstream fixes and improvements
- Qt6 is already a proven platform—projects like QField and Mergin Maps have been using it successfully in production for quite some time
- Migrating to Qt6 ensures QGIS stays aligned with a supported, modern framework and unlocks new performance, rendering, and UI capabilities
Release Strategy
To ensure a smooth transition for users and developers, a phased approach has been adopted:
- Support for QGIS 3.40 LTR will be extended by 4 additional months, until May 2026, giving plugin developers and organizations extra time to adapt
- QGIS 4.0, scheduled for October 2025, will be a regular release
- QGIS 4.2, scheduled for February 2026, will be the next official LTR
This gradual rollout ensures that users who depend on stable environments can continue with 3.40 LTR, while early adopters and plugin developers move forward with Qt6 in version 4.0.
Plugins
Measures are being implemented to facilitate preparation for plugin developers:
- The QGIS Plugin Repository will begin accepting plugins compatible with version 4.x
- The plugin site will inform users if a plugin is Qt6-compatible
- A comprehensive migration guide is being developed to support developers during the transition
For those who maintain plugins, now is the ideal time to start testing and preparing for Qt6 compatibility.
Available resources:
- pyqgis4-checker
- Plugin migration guide
Try Qt6 Now
The migration to Qt6 is already underway and available for testing:
- Windows: Qt6 builds of all release branches and master are available through the OSGeo4W installer
- Linux (Debian): Qt6 support is almost ready, with work in progress to allow Qt5 and Qt6 to coexist
- macOS: Qt6 packages will start building as soon as QGIS 3.44.0 is released and the QGIS 4.0 development cycle begins
Get Involved
The project will share more updates in the coming weeks. In the meantime, the community is invited to:
- Try the Qt6 builds
- Test plugins for compatibility
- Stay informed through qgis.org and community channels
The QGIS project thanks all contributors, developers, testers, and organizations supporting this transition. QGIS 4.0 is shaping up to be a significant leap forward, and the team is eager to share it with the community.