What Is a 3MF File? 3MF vs STL Explained
Definition
3MF (3D Manufacturing Format) is a file format for 3D printing that stores meshes in defined units together with colors, materials, multiple objects, their positions on the build plate and, often, print settings. It is a zip archive of XML files maintained by the 3MF Consortium.
Also called: 3D Manufacturing Format, .3mf.
3MF was created to fix STL's limits. An STL is a bag of triangles with no units or color. A 3MF describes the whole job: which objects, in which units, where on the plate, in which materials and colors.
Inside a 3MF
Rename a .3mf to .zip and you can look inside. The model lives in 3D/3dmodel.model, an XML file with vertices and triangles. Slicers such as Bambu Studio and PrusaSlicer store extra objects and settings in more files, linked with the 3MF Production extension.
Converting
Need an STL? Use the 3MF to STL converter, or read how to convert 3MF to STL. To just look at a file, open it in the STL viewer.
Questions
Is 3MF better than STL?
For printing, usually yes: it carries units, colors, multiple objects and settings, and files are compressed. STL is simpler and more widely supported by older software.
How do I open a 3MF file?
Open it in a slicer such as Bambu Studio, OrcaSlicer, PrusaSlicer or Cura, or in a viewer that supports 3MF, like the Depthue STL viewer.