Free tool

Convert 3MF to STL

Drop a .3mf, get a clean binary STL. Multi-object projects and build transforms are handled, and nothing is uploaded.

Runs in your browser. Nothing is uploaded.

How to use it

1Drop your .3mf
From Bambu Studio, OrcaSlicer, PrusaSlicer, Cura or a model site. It is read on your device.
2Check the objects
Every object on the plate is listed with its triangle count. Untick any you do not want.
3Choose the output
One merged STL keeps objects where they sit on the plate. STL per object gives a zip with one file per part.
4Download
Download the binary STL or the zip, then check it in the STL viewer if you like.

What gets converted

The converter reads every .model file in the 3MF, follows components across files, applies each component's and build item's transform, and converts units to millimetres. Only objects on the build plate are exported, the same set your slicer would print.

What does not survive

STL is geometry only. Colors, materials, supports, modifiers and slicer settings stay in the 3MF, so keep it as your master copy.

Other ways to convert

Bambu Studio, OrcaSlicer, PrusaSlicer and Cura can all export STL from an open 3MF, and Blender can with an add-on. The menu path for each is in how to convert 3MF to STL. Upload converters such as AnyConv also work, but your file goes to their server; AnyConv compared covers when that matters. To go the other way, the STL to 3MF converter combines STLs into one project, and the STL file converter handles OBJ, GLB and PLY.

Questions

Can a 3MF file be converted to STL?

Yes. The geometry converts fully: every object on the plate, at its size and position. Colors, materials, supports and print settings do not, because STL stores only the mesh.

Is 3MF or STL better for 3D printing?

3MF, for your own projects. It keeps units, colors, multiple objects and slicer settings in one file. STL is geometry only, but every slicer, CAM program and print service accepts it. Keep the 3MF as your master and export STL when a tool asks for it.

How do I convert 3MF to STL in Bambu Studio?

Open the 3MF, then use File, Export and pick the STL option: all objects as one merged STL, or each object as its own STL. To export one part, select it, right-click and export it as STL.

Is my 3MF uploaded?

No. The file is unzipped and converted in your browser.

Does it support Bambu Studio 3MF files?

Yes. It follows the 3MF Production extension that Bambu Studio, OrcaSlicer and PrusaSlicer use for multi-object projects, including component files and transforms.

Why are colors missing in my STL?

STL cannot store color. Export one STL per object if your model uses separate parts for each color.

What units does the STL use?

Millimetres. The converter reads the 3MF's unit and converts inches, centimetres or microns to millimetres.