What is a 3MF file?

A 3MF file (3D Manufacturing Format) is a 3D printing file that stores a model together with its unit, colours, materials and the layout of the build plate. It is a zip archive of XML files, published by the 3MF Consortium in 2015, and it is the project format of Bambu Studio, PrusaSlicer, OrcaSlicer and Cura.

Drop your 3MF file here

Extension	.3mf
Name	3D Manufacturing Format
Created by	3MF Consortium (Microsoft, Autodesk, HP and others), 2015
Stores	Meshes, units, colours, materials, several objects, build plate
Container	Zip archive of XML
Units	Stored in the file, usually millimetres
Opens in	Bambu Studio, PrusaSlicer, OrcaSlicer, Cura, this page

What 3MF fixes compared with STL

STL was designed in 1987 and stores only triangles. 3MF was designed to keep everything a print job needs in one file.

The unit is stored, so a model can no longer arrive 25 times too small.
Vertices are shared between triangles, so the same mesh is much smaller, and compressed as a zip on top.
Colours and materials are stored per object or per triangle, which multi-colour printers need.
Several named objects keep their positions on the plate.
Slicers add their own settings, such as supports and print profiles, so a project reopens exactly as you left it.

A 3MF from one slicer in another

The model data in 3MF is standard, so any slicer reads the shapes and their positions. Print settings are not standard: Bambu Studio, PrusaSlicer and Cura each store their own, and the other slicers ignore them. Expect the model to open everywhere and the settings only in the slicer that wrote them.

How to open a 3MF file

Use the viewer at the top of this page to look at it without installing anything. To print it, open it in Bambu Studio, PrusaSlicer, OrcaSlicer or Cura, all free. To get a plain STL for an older printer or a tool that does not read 3MF, use the 3MF to STL converter.

Free tools for 3MF files

3MF to STL Turn a .3mf from your slicer into a plain .stl any printer accepts. 3D file viewer Open any common 3D file in your browser. STL viewer Open a .stl file and check the mesh before you print it.

Frequently asked

Is 3MF better than STL?

For printing, usually yes. It is smaller, it stores the unit, and it keeps colours and several parts. STL is still the safest choice when you send a file to an unknown tool or service, because everything reads it.

Can I convert 3MF to STL?

Yes, with the 3MF to STL converter on this site, in your browser. The shape and the plate positions are kept. Colours, materials and print settings are lost, because STL cannot store them.

Why is my 3MF file so small?

3MF shares vertices between triangles and compresses everything as a zip archive. The same mesh is often several times smaller as 3MF than as binary STL.