What does PrusaSlicer 3.0 change for someone who prepares prints daily?

A project system that replaces the old single-bed workflow

PrusaSlicer 2.9 introduced multiple beds but kept the implementation minimal. Version 3 makes beds real parts of the project. Each bed now carries its own configuration. You can prepare several beds in one project, slice them independently, use different profiles, and even mix many different printers in the same project. Prepare a batch for your MK4S and your XL side by side, in one window. Models drag from one printer to another. The 9-bed limit from 2.9.x is gone. When you slice, beds are processed in parallel. Even if you own just one 3D printer, you can create beds for different materials or settings and manage an entire project within a single file.

Multiple projects open in a single PrusaSlicer instance, each in its own tab. Individual projects keep their own context: open dialogs, active tools, selections. Nothing bleeds between them. The application also continuously backs up open projects locally. If the application crashes, your work can be recovered from the backup_projects folder in the PrusaSlicer data directory.

A profile system built for printers with multiple nozzles

The old profile system could not really describe a printer like the Prusa XL. On that machine you can have a different nozzle on each tool. One tool can use a 0.25 mm nozzle for fine details, another a 0.4 mm for everyday printing, and another a 0.6 mm for large strong parts. They are all installed and ready to be used. Previously you often needed three separate printer profiles and had to switch between them depending on which tool you wanted to use. Setting up advanced prints that would combine the different nozzles in one print was not just clumsy but also difficult.

The whole print profile system is now layered and designed around modern multi-tool printers. PrusaSlicer can describe the hardware you actually have instead of forcing it into one fixed combination of settings. Choosing a nozzle for a print becomes as easy as choosing the tool from a select box. You can even assign whole different print or printer profiles to individual tools and mix them as needed. The preset updater has been rewritten. Preset Sources & Updates now gives you one place to manage both online and local preset sources. The profile format itself has moved from .ini to .yaml, and the whole data structure is new. Old 3MF projects from PrusaSlicer 2.x load correctly. Configurations are transformed and matched to the right system profiles automatically.

The new interface and what moved where

The user interface was thrown out completely and written from scratch. The new layout puts tools at the top, a scene browser to the left and a contextual panel to the right. Many things are still roughly where you are used to having them, but not all of them. Keyboard shortcuts are mostly the same. The right panel is now fully contextual. If you have the painting tool active, you see everything related to painting, not the current infill percentage. It shows profile settings when a bed is selected, object-specific options when an object is selected, and tool controls when a tool is active. The scene browser has its own collapsible panel so it does not crowd the viewport. G-code preview has a basic view for quick checks and an inspection mode for detailed analysis. A View Cube handles camera control. A light mode sits alongside the default dark theme. Viewport navigation is smoother, and the camera automatically centers on a bed when you select it. You can also choose the mouse navigation you are already familiar with. PrusaSlicer now includes navigation schemes matching Tinkercad, Blender, SolidWorks and Fusion.

The 3D viewport also got a significant upgrade. More advanced OpenGL rendering adds shadows and reflections. Ambient occlusion is also added to make the 3D scene better at matching real life and give you a clearer sense of how objects sit on the bed. All of it is configurable in Preferences, and you can turn it off entirely if you prefer the classic look or if your GPU is limited. The preview can now handle substantially more complex geometry before it starts to lag. When the scene is too dense, toolpaths are hidden during rotation and only rendered when the camera stops. You get smooth navigation even on heavy prints, and full detail the moment you need it.

Favorite settings and a plugin system that runs in a sandbox

You can mark individual settings as favorites. Favorite settings then appear directly in the right panel for quick access. Instead of opening the full settings pages all the time, you build your own small set of everyday controls. Power users still have access to everything, but many users may find that their normal workflow becomes much faster and cleaner.

Plugins change how the community extends the slicer. With PrusaSlicer 3.0, the community can extend the slicer without forking it, without waiting for a pull request to be merged. Custom calibration prints, QR code generators, automatic model orientation, custom infills — your imagination is the limit, and the current API. For start, Prusa picked one area where plugins can be really useful: calibration prints. PrusaSlicer 3.0 comes with two built-in parametric calibration prints: Flow tower, and Temperature Tower. You select the desired print, type in the parameters in a dialog, confirm, and a project containing an object and settings materializes. You can then save or slice it like any other project. The dialog and the whole project generation logic are not embedded inside PrusaSlicer source code but distributed alongside it in the form of a Lua plugin.

The application scans the plugin folder and builds the menu items dynamically. The plugin defines its inputs, PrusaSlicer builds the parameter input dialog accordingly and passes the values to the plugin when it is executed. The Lua API is now experimental and subject to change. Currently existing plugins are of project.plugin type — their purpose is to create objects programmatically. The architecture is ready for more plugin types with their own purposes. The API currently revolves mainly around adding something new to the scene rather than being able to manipulate what is already there. A community plugin marketplace will be included in one of the next releases. Plugins run in a sandbox by default. They have no general access to your disk, no access to your data outside of the loaded project, and no access to HTTP or sockets. Other network communication is also blocked. Plugins submitted to the marketplace also go through a review process. You can still install unverified plugins at your own risk; they may contain bugs, slow PrusaSlicer down or even crash it, but the sandbox is designed to stop them from reaching outside the slicer.

Offline mode and what it actually blocks

The slicer gains a new offline mode where the networking libraries are not even loaded. You can selectively disable every online service — Connect, Printables, even profile update checks — before any network communication happens. In full offline mode the networking libraries are not loaded at all. PrusaSlicer runs in complete isolation. No firewall alarms, no background connections. Airgapped and restricted environments are fully supported. The new plugin system is designed with security in mind too, with full sandboxing. This ties with the upcoming Prusa Connect Local, a little cloud running in your home or on premise. The company states they do not want to see your files and they are the most secure on your hardware.

Performance and compatibility; what still does not work

Thanks to the big internal refactoring, PrusaSlicer starts faster, slicing is faster, and whole projects with multiple beds can now be sliced in parallel. The proven architecture of the slicing backend was kept, although substantial changes in the backend code were done as well. Side-by-side installation works: PrusaSlicer 3.x saves profiles into a separate directory and runs alongside 2.x with zero conflicts. 3MF from PrusaSlicer 2.x loads with both geometry and settings. Your modified values stay flagged as modified. 3MF from PrusaSlicer 3.x in 2.x loads geometry only; settings are discarded. PrusaSlicer 2.9.1+ will notify you about this. Third-party 3MF from Bambu Studio or OrcaSlicer imports as geometry. STL, OBJ, STEP work as expected.

This is an early preview, not a polished nearly-ready alpha. Some issues are known, others are not. The preview build is not feature complete when compared to 2.9.6. A large part of the application was rewritten from scratch and reimplementing everything takes time and effort. Some features have to wait for 3.1.0 to be fully reimplemented. You can find the list of unfinished features at the end of the change log. The Linux flatpak was still compiling during the community stream on launch day and was not available in Flathub-beta at release. Currently the preview only supports Prusa printers; support for other printers is planned as development progresses.