Free online 3MF to SCAD converter

What the 3MF format is

3MF is a ZIP-based 3D-printing container standardized by the 3MF Consortium. It can store one or more models, mesh geometry, units, colors, materials, object transforms, thumbnails, and slicer or print-package metadata.

PrusaSlicer, OrcaSlicer, Bambu Studio, UltiMaker Cura, Microsoft 3D Builder, Fusion 360, SolidWorks, and other CAD or slicing applications can create or export 3MF files. You commonly encounter them when downloading a printable model, saving a slicer project, or transferring a prepared print between devices.

What the SCAD format is

SCAD is the plain-text source format used by OpenSCAD. Instead of storing only a finished surface mesh, it describes geometry with commands such as cube(), cylinder(), union(), difference(), transformations, variables, and modules.

SCAD is useful for models that must be edited by dimensions or regenerated from parameters. A mesh converted from 3MF does not automatically become equivalent SCAD source code: curved surfaces, boolean operations, constraints, feature history, and original parameter names cannot generally be recovered from a print mesh.

How to actually convert 3MF to SCAD

Online conversion

For a straightforward conversion without installing software, use the free 3MF conversion tool on 101convert.com. Upload the .3mf file, choose SCAD as the output format if available, run the conversion, and download the resulting .scad file. Inspect the output in OpenSCAD before using it for fabrication, especially when the 3MF contains multiple objects or slicer-specific metadata.

Desktop workflow through STL

1. Open the 3MF in a slicer or 3D application that preserves the required objects. In PrusaSlicer, OrcaSlicer, or Bambu Studio, use File → Import or open the project file.
2. Export the required object or assembled plate as model.stl using File → Export or the application’s equivalent mesh-export command. Export individual objects when you need separate placement or editing in OpenSCAD.
3. Create a new text file containing import("model.stl"); and save it as model.scad in the same directory as the STL.
4. Open model.scad in OpenSCAD. Press F6 to render the imported mesh, then use File → Export → Export as STL only if you need a new mesh output.

The SCAD file in this workflow is a wrapper around the STL; it does not contain editable OpenSCAD primitives. You can add transformations such as scale([1, 1, 1]) import("model.stl"); or combine the import with OpenSCAD-generated geometry.

Quality, compatibility, and limitations

Check the unit setting during export. STL has no embedded unit standard, while 3MF stores units explicitly; an incorrect millimeter-to-inch interpretation can change the model size by a factor of 25.4.

A 3MF project may contain slicer settings, supports, build-plate placement, colors, and multiple instances. STL export normally preserves only triangle geometry, so those details are discarded unless the source application exports them separately.

OpenSCAD can display and use an imported mesh, but mesh operations may be slow for high triangle counts. Use a decimation or remeshing tool before import when the 3MF contains millions of triangles, and verify manifoldness, normals, scale, and orientation in the resulting file.

If the original model was designed parametrically in a CAD program, obtain its native source format instead. A 3MF-to-SCAD conversion can preserve printable shape, but it cannot reliably reconstruct the original CAD feature tree or editable design intent.