PrusaSlicer 3.0 Is the Biggest Rewrite in Slicing History

A slicer rebuilt from the ground up

Prusa released the first public preview of PrusaSlicer 3.0 on September 1, 2026. The company calls it the biggest upgrade in the slicer's history, and the changes back that claim. Josef Prusa wrote that the team threw out the user interface completely and rewrote it from scratch, driven by how people actually use slicers in 2026.

The timing is deliberate. September 1 marks 15 years since the very first Slic3r commit. PrusaSlicer started as a fork of Slic3r, and this release signals a clean break from that original architecture.

Multi-bed projects change the workflow

PrusaSlicer 2.9 introduced multiple beds as a minimal feature. In 3.0, beds are real parts of the project. Each bed can carry its own configuration, profile, and even printer. You can slice an MK4S and an XL in the same window, drag models between them, and slice beds in parallel. The old 9-bed limit is gone.

Multiple projects can also stay open in one instance, each in its own tab with independent context. If the application crashes, local backups restore your work. Power users who once ran six PrusaSlicer instances simultaneously can finally consolidate.

Profiles built for multi-tool printers

The old profile system could not describe modern multi-tool machines well. A Prusa XL with three tools, each with a different nozzle size, needed separate profiles. Switching between them was clumsy. PrusaSlicer 3.0 replaces that with a layered profile system. Choose nozzles from a dropdown, assign different print settings to individual tools, and mix them in the same job.

The preset format moved from .ini to .yaml. PrusaSlicer 2.x 3MF files load with geometry and settings intact. Third-party 3MF files from Bambu Studio or OrcaSlicer import as geometry. The two major versions install side by side without conflicts.

A new interface that learns from the competition

The right panel is now fully contextual. Selecting a painting tool shows painting options, not infill percentages. The scene browser collapses into its own panel. A View Cube handles camera control. Mouse navigation schemes match Tinkercad, Blender, SolidWorks, and Fusion 360. A light mode joins the dark theme.

The 3D viewport uses advanced OpenGL rendering for shadows, reflections, and ambient occlusion. It stays responsive under heavy geometry by hiding toolpaths during rotation and rendering them only when the camera stops.

Plugins instead of forks

PrusaSlicer has always been open source, and forks like OrcaSlicer, SuperSlicer, and Bambu Studio came from that freedom. Prusa's argument is that forking fragments progress. Plugins let the community extend the slicer without maintaining a separate fork. A community plugin marketplace is part of the preview.

The company chose AGPLv3 licensing despite the GUI rewrite being large enough to technically allow a closed-source fork. That keeps the source open for anyone who wants to modify it.

What is still missing

This is an early alpha, not a near-production build. Some features from PrusaSlicer 2.9.6 are not yet ported. The Prusa team says those will arrive in 3.1.0. If you rely on advanced features that have not been reimplemented yet, stay on 2.x for now.

Users who want to try the preview can download it from Prusa's website. The community is expected to find bugs and shape the final release through feedback on GitHub and the Prusa forum.