Flsun Slicer review
A free, open-source FDM slicer with model preparation, G-code preview, and remote monitoring.
Reviewed by iTechGuides Editors · Editorial team · Updated Nov 2026
Flsun Slicer is desktop software for preparing FDM 3D printer jobs, with a free, open-source distribution. It suits solo users and small teams, particularly those already working with FLSUN printers, who want model preparation and printer settings in one slicer. The workflow covers importing STL, 3MF, STEP, OBJ, and other model formats, then adjusting models and configuring print parameters before slicing.
Model preparation is a notable strength: users can scale, rotate, move, copy, or split models and parts, and the software can arrange models on the build plate. It also supports cutting models and drawing supports, with ordinary, advanced, and expert modes for different levels of control. Printer, filament, and process settings are configurable, and G-code preview offers a way to inspect the resulting file. This breadth makes it a fit for users who want more than basic slicing without paying for a proprietary tool.
FLSUN lists Windows and macOS 64-bit desktop builds and describes remote control and monitoring capabilities. The software is based on PrusaSlicer and licensed under AGPL-3.0. A relevant boundary is printer compatibility: the S1 FAQ says connecting to printers from other brands is not currently planned, so buyers seeking broad cross-brand remote control should consider another option. FDM users comfortable with desktop software and an open-source project are the clearest match; users who need other printer types or wider platform coverage should look elsewhere.
Flsun Slicer pros and cons
- Where it wins
- Slices STL, 3MF, STEP, OBJ, and other model formats
- Supports model edits, automatic plate arrangement, cutting, and supports
- Includes G-code preview and remote control and monitoring
- Where it doesn't
- Desktop builds are limited to Windows and macOS
- Designed for FDM printing, not other printer types
- S1 FAQ says connections to printers from other brands are not currently planned
Flsun Slicer fact sheet, pricing and score →
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