# What is a 3MF file?

> A 3MF file (.3mf, 3D Manufacturing Format) is a ZIP package containing an XML description of one or more 3D models, published by the 3MF Consortium in 2015 as a modern replacement for STL. Unlike STL, it records units in millimetres, colours, materials, several objects and slicer settings. Modern slicers open it directly.

URL: https://kenerateai.com/what-is-a-3mf-file
Publisher: Kenerate AI (https://kenerateai.com)
Last updated: 2026-10-02

## Key facts
- Full name: 3D Manufacturing Format
- Published by: 3MF Consortium, 2015
- Container: ZIP with XML model
- Stores: Units, colours, materials, objects, settings
- Opens in: Bambu Studio, PrusaSlicer, OrcaSlicer, Cura

## In depth

### What's inside a 3MF
Rename a .3mf to .zip and you can look inside: a content-types file, relationships, and a 3D/3dmodel.model XML file listing vertices and triangles that share them, plus a unit [1]. Slicers add thumbnails, colour data and their own settings as extra parts of the package.

### 3MF vs STL in one table
Units — Stored (mm by default) [1] — None [2]
Colours / materials — Yes — No
Several objects — Yes, with positions — One triangle list
Vertices — Shared — Repeated per triangle
Compression — ZIP — None
Support — Modern slicers — Everything

### Why slicers moved to 3MF
The 3MF Consortium — founded by companies including Microsoft, Autodesk, HP and Shapeways — designed the format to carry everything a print needs in one file [1]. Saving a project as 3MF keeps the plate layout, colours and settings together, which STL never could [2].

### How to open or convert a 3MF
- Open: Bambu Studio, PrusaSlicer, OrcaSlicer, Cura, Windows 3D Builder — or the free online 3D viewer.
- Convert to STL: for older tools; colours and settings are dropped.
- Convert from STL: STL to 3MF adds a unit and shares vertices, usually shrinking the file.

References:
[1] 3MF Consortium — 3MF specification: https://3mf.io/specification/
[2] Wikipedia — STL (file format): https://en.wikipedia.org/wiki/STL_(file_format)

## FAQ
Q: What does 3MF stand for?
A: 3D Manufacturing Format.

Q: Is 3MF better than STL?
A: For printing, usually: it stores units, colours and multiple objects. STL is simpler and opens everywhere.

Q: How do I open a 3MF file?
A: In a modern slicer, Windows 3D Builder, or an online 3MF viewer.

Q: Can I convert 3MF to STL?
A: Yes — the geometry converts cleanly; colours and slicer settings are dropped.

Q: Can Blender open 3MF files?
A: Not out of the box — Blender has no built-in 3MF importer, though a free 3MF add-on adds one. The quick route is to convert the 3MF to GLB, OBJ or STL with the free 3D model converter and import that.

Q: How do I edit a 3MF file?
A: Open it in a slicer such as Bambu Studio, PrusaSlicer or OrcaSlicer to move, scale, paint colours or change settings, then save it again as 3MF. To reshape the mesh itself, convert it to STL or OBJ and edit it in Blender or the free STL editor.

Q: Why is my 3MF from Bambu Studio big?
A: Project 3MFs can include thumbnails, settings and sometimes sliced data alongside the model.

## Related pages
- 3MF to STL: https://kenerateai.com/3mf-to-stl
- STL to 3MF: https://kenerateai.com/stl-to-3mf
- 3MF vs STL: https://kenerateai.com/3mf-vs-stl
- What is an STL file?: https://kenerateai.com/what-is-an-stl-file

## Sources
- 3MF Consortium — 3MF specification: https://3mf.io/specification/
- Wikipedia — STL (file format): https://en.wikipedia.org/wiki/STL_(file_format)