SuperSlicer

SuperSlicer is the slicer for people who read the settings. It's a free, open-source slicing program for FDM 3D printing, released under the AGPLv3, and it's a fork of PrusaSlicer - itself a descendant of the original Slic3r - that keeps everything good about its parent and then bolts on every tuning knob the community ever asked for. It takes your 3D model and turns it into the G-code your printer actually executes.

The headline feature is calibration. SuperSlicer builds the whole tuning workflow into the app: temperature towers, flow rate tests, retraction tuning, bed leveling checks, bridge and overhang tests, pressure advance calibration. What used to be an evening of downloading test prints from forums is now a menu entry. On top of that, you get more settings than any other mainstream slicer: per-object and per-layer control of nearly everything, custom G-code hooks, ironing options, seam placement tuning, and firmware-aware output flavors for Klipper, Marlin, RepRap and more.

Because it's built on PrusaSlicer's codebase, you keep the familiar three-tab interface, plater tools, paint-on supports, multi-material support and a large library of printer profiles. Your PrusaSlicer knowledge transfers directly, and it reads the same 3MF project files, so switching tools doesn't orphan your existing projects. Built-in OctoPrint, Klipper and Duet integration sends finished G-code straight to the printer. The developer, supermerill, ships new builds on a rolling basis - version 2.7.61.10 landed on September 18, 2025 - and the project has a busy community on GitHub and Discord where features get debated, tested and merged.

Our verdict: if you know what pressure advance is, or you want to learn, SuperSlicer is the most powerful free slicer you can install. Beginners should start with PrusaSlicer or OrcaSlicer and come here when they hit the walls. When you're ready to really dial in a printer, this is where the rabbit hole begins - and it's a deep, rewarding one.

Logo: SuperSlicer project.