3MF to STL converter: the surface, as it is
Drop a .3mf and get one .stl file, converted in Blender on our server. The trip keeps the geometry and nothing more; nothing the source holds is lost on the way. Free, no account, nothing to install.
How do I convert 3MF to STL?
Drop the file on this page, wait while the server converts it, and download one .stl file.
- 1Choose a .3mf. Files up to 50 MB.
- 2The converter opens it in Blender on our server and writes STL. Most files take under a minute; the page shows the result in 3D when it is done.
- 3Download one .stl file. The upload and the result are deleted 3 days later.
- In:
- .3mf
- Out:
- one .stl file
- Keeps:
- the geometry
- Cost:
- free, no account
What survives the trip
A 3MF is a zip package with the parts as triangle meshes, a colour or material per part, and the unit written in the file (millimetres by default). Each part comes in as its own object with its own material, so a two-colour print stays two colours, and a 100 mm part arrives as 100 mm. A package whose build names a part that cannot be read is refused rather than converted in part. Going to STL, the STL is written in millimetres too.
The result is a binary STL of every mesh in the file, merged into one solid, written in the pose the model holds. Materials, textures, bones and shape keys do not exist in STL and are not written.
3MF and STL do not hold the same things, and the page says so before you upload: the trip keeps the geometry and nothing more, and nothing the source holds is lost on the way. STL is what every slicer and every CAD tool reads.
What this conversion cannot do
Measured on real files, not assumed. Everything below is a property of the formats or of the pipeline, and knowing it beforehand is cheaper than discovering it in your 3D tool.
Colour per part, not per pixel
A 3MF names a colour or a material for each part, and that is what is read. Painted multi-colour prints that store a colour per triangle are read as the part's base material; slicer-specific extras (supports, plates, modifiers) are not read at all.
Converted is not the same as printable
Nothing is repaired, thickened or made watertight. A model built for rendering is a set of open shells, and a slicer will show the holes. That is a modelling job or the repair step in your slicer, not a format conversion.
Uploads stop at 50 MB
A larger file is refused before anything is uploaded. Decimate a dense mesh or shrink the textures in your 3D tool first; neither changes the format.
Frequently asked questions
Will the colours of my multi-material print survive?
The colour of each part does: each part keeps its material. Per-triangle paint and slicer settings do not; they are not part of the 3MF core that is read.
My model has several parts. Do I get several files?
No, one STL with every mesh in it. Split it in your slicer or 3D tool if you want the parts apart.
Is anything uploaded, and for how long?
Yes: the file you drop goes to our server in New York, is converted there, and both the upload and the result are deleted 3 days after the conversion. Nothing is shared with anyone.
Can I look at the 3MF first?
Yes, without uploading anything: the 3MF viewer draws it in your browser. Open the 3MF viewer →
Can this become a VTuber avatar?
Not as it is: an avatar needs a skeleton, skin weights and a face that moves, and a .3mf has none of them. Rig and texture the model in Blender first, then convert the rigged file to VRM.
The other format pairs
All 50 are free, all run the same pipeline, and all say what they drop.
STL to GLB
STL in, GLB out, free: one file.
STL to FBX
STL in, FBX out, free: one file.
STL to OBJ
STL in, OBJ out, free: zipped with its files.
GLB to STL
GLB in, STL out, free: one file.
FBX to STL
FBX in, STL out, free: one file.
OBJ to STL
OBJ in, STL out, free: one file.
STL to PLY
STL in, PLY out, free: one file.
STL to DAE
STL in, DAE out, free: zipped with its files.
STL to USDZ
STL in, USDZ out, free: one file.
PLY to STL
PLY in, STL out, free: one file.
DAE to STL
DAE in, STL out, free: one file.
USDZ to STL
USDZ in, STL out, free: one file.
3MF to GLB
3MF in, GLB out, free: one file.
3MF to FBX
3MF in, FBX out, free: one file.
3MF to OBJ
3MF in, OBJ out, free: zipped with its files.
STL to 3MF
STL in, 3MF out, free: one file.
GLB to 3MF
GLB in, 3MF out, free: one file.
FBX to 3MF
FBX in, 3MF out, free: one file.
OBJ to 3MF
OBJ in, 3MF out, free: one file.
Only want to look at the file? GLB viewer, FBX viewer and OBJ viewer all run on your own device — nothing is uploaded.
Is your model going into VTubing?
A .3mf is a surface without a skeleton, so no converter can make a VRM avatar out of it directly. Rigged and textured in Blender, the same model converts to VRM on the FBX to VRM converter, with the bones mapped onto the VRM humanoid.
Open the VRM converter