QGIS 4.0 in February 2026: What Qt6 Changes

Introduction

QGIS is updated regularly, and it has been announced that “QGIS 4.0” will arrive in October 2025 February 2026. The look and features stay the same as before, but internally there is a major change: the move to Qt6.

QGIS 4.0 was originally scheduled for release in October 2025, but the date has changed to February 2026.

This is an important change that turns QGIS into easier-to-use, higher-performance software. This article gives an overview of QGIS 4.0 and explains what it means for users.

QGIS 4.0 changes and schedule

Moving to Qt6 in QGIS 4.0

QGIS is built on Qt (pronounced “cute”), a cross-platform application framework. It serves as the “engine” or “framework” that runs QGIS.

The current QGIS (the 3.x series) runs on Qt5, and it is moving to Qt6. Qt6 has a more modern structure that is easier to adapt to future technical advances, which is a big step forward for long-term stability and maintainability.

Qt6 is a proven platform and is already used in projects such as QField and Mergin Maps.

Upcoming schedule

The QGIS project has announced the following schedule for the move to Qt6 and the release of QGIS 4.0.

• February 2026: QGIS 4.0 release (a regular release, not a long-term release (LTR))
• October 2026: QGIS 4.2 designated as the LTR

The plan is to release QGIS 4.0 first as a regular version to support the transition period, and then provide QGIS 4.2 as the LTR, which suits long-term use. QGIS users and plugin developers should use this schedule as a guide to prepare for the upgrade.

Benefits for QGIS users

1. Better performance ahead

QGIS 4.0 itself does not add major new features, but the move to Qt6 becomes the foundation for future development. Qt6 includes an improved and faster rendering engine and support for modern UI features, so QGIS itself is expected to run more smoothly.

2. The reassurance of using QGIS as before

Many users wonder whether their existing plugins will still work. QGIS 4.0 is designed with compatibility with existing plugins and scripts in mind.

A full migration takes time, so to make sure things at least run for now, the project decided to keep the deprecated QGIS APIs in place for the time being. This lets plugin developers move to Qt6 step by step, and users are expected to keep using QGIS without major disruption.

3. Multiple versions can run side by side

QGIS lets you install and use multiple versions at the same time. If you want to keep using the LTR but also try the new QGIS 4.0, you can do both. This is a big reassurance for people who use QGIS for work.

Getting ready to upgrade

If you currently use QGIS 3.40 LTR, you do not need to do anything special. It is supported until May 2026, so you can keep using it with confidence.

If you use many plugins, or depend heavily on a particular plugin for work, do not rush to move right after QGIS 4.0 is released. Check each plugin's support status first, and then migrate.

The official QGIS plugin repository is also set to let you see a plugin's Qt6 support status at a glance on its page.

Conclusion

QGIS is steadily evolving to the next stage while keeping its stable operation. Keep an eye on QGIS 4.0. QGIS LAB plans to keep publishing articles about QGIS 4.0, so check back for updates if you are interested in the latest information.

QGIS LAB also introduces the features added in each new release. Take a look at those as well.