QGIS 4.0 launches with Qt6 migration, over 100 new features, and some deprecated APIs

QGIS 4.0 has been released, marking a substantial update for this widely used open source geographic information system. This latest version is the result of a long-term technical migration that transitions the software core to the Qt6 framework.

Building on this architectural change, QGIS 4.0 maintains a familiar experience for users while introducing major backend enhancements. These updates boost maintainability and unlock the potential for integrating modern libraries. The changes also deliver measurable improvements in performance and code security, ensuring the platform remains adaptable for future developments.

In parallel with the migration, the developer community contributed over 100 new features across the application. These additions enhance the platform’s flexibility and increase the security of spatial data workflows.

Plugin developers are a key focus in this release. Deprecated APIs are retained wherever feasible, simplifying the process of updating third-party tools. However, not all legacy APIs are guaranteed support throughout the lifetime of the QGIS 4.x series, so ongoing adaptation may be needed for some plugins.