PrusaSlicer 3.0 Is a Slicer Rewrite, Not an Update

Prusa Research shipped the first public preview of PrusaSlicer 3.0 on September 1, 2026. The release date was not a coincidence: it marks exactly 15 years since the very first Slic3r commit. What they released is not a collection of new features bolted onto the old codebase. It is a ground-up rewrite of the user interface, the profile system, and the project management layer, with substantial changes to the slicing backend as well.

What changed

The old interface showed its age. Features were buried in menus, the layout intimidated new users, and adding anything new required working around decisions made years earlier. PrusaSlicer 3.0 throws the UI out entirely. The new layout puts tools at the top, a scene browser on the left, and a fully contextual right panel that changes based on what you are doing. Keyboard shortcuts mostly stay the same.

The profile system got the same treatment. Old PrusaSlicer could not properly describe a multi-tool printer with different nozzles on each tool. You ended up juggling three separate printer profiles and switching between them. The new system is layered and built around real hardware. Choosing a nozzle is now as simple as picking from a select box. Preset management moved from .ini to .yaml format, and the updater now gives you one place to manage both online and local preset sources.

Multiple beds and projects

PrusaSlicer 2.9 introduced multiple beds as a minimal feature. In 3.0, beds are real project components. Each bed has its own configuration, and you can mix different printers in the same project. The 9-bed limit is gone. Beds slice in parallel. You can also open multiple projects in tabs, each with its own context, instead of running six separate PrusaSlicer instances. Projects back up continuously to a local folder, so a crash does not wipe your work.

Plugin system and offline mode

PrusaSlicer has always been open source, and forks such as OrcaSlicer, BambuStudio, and SuperSlicer came from that openness. Forks diverge, though, and improvements do not always flow back. PrusaSlicer 3.0 introduces a plugin system designed to let the community extend the slicer without forking the whole project.

Plugins run in a sandbox by default with no access to your disk, network, or data outside the loaded project. A community plugin marketplace will arrive in a later release. The first built-in plugins are two parametric calibration prints: a flow tower and a temperature tower.

The offline mode is a direct answer to user concerns about background connections. In full offline mode, the networking libraries are not loaded at all. PrusaSlicer runs in complete isolation. Every online service, including Connect, Printables, and profile update checks, can be selectively disabled before any network communication happens.

Performance and viewport

PrusaSlicer 3.0 starts faster and slices faster than 2.x. The 3D viewport now uses advanced OpenGL rendering with shadows, reflections, and ambient occlusion. Toolpaths hide during rotation on dense models and render fully when the camera stops. The viewport includes a View Cube and navigation schemes matching Tinkercad, Blender, SolidWorks, and Fusion 360. A light mode sits alongside the default dark theme.

What is missing

This is an early preview, not a finished alpha. Some features from 2.9.6 are not yet ported and will arrive in 3.1.0. The list of unfinished items is published in the changelog. Old 3MF projects from PrusaSlicer 2.x load with geometry and settings intact. Third-party 3MF files from Bambu Studio or OrcaSlicer import as geometry. PrusaSlicer 3.x saves profiles to a separate directory and runs alongside 2.x with zero conflicts.

PrusaSlicer 3.0 remains open source under AGPLv3. The preview is available now from prusa3d.com.