What is a 3MF file?

3MF (3D Manufacturing Format) is a 3D printing file format created by the 3MF Consortium, an industry group founded by Microsoft, HP, Autodesk and other companies. A 3MF file is a ZIP archive with the model, its units and colours, and often a slicer's project settings.

What is inside a 3MF

Rename a .3mf to .zip and you can open it like any archive. Typical contents:

3D/3dmodel.model — the main model: an XML list of vertices and triangles, objects, colours and where each object sits on the build plate.
3D/Objects/*.model — in Bambu Studio and OrcaSlicer projects, the actual meshes are often stored in these separate files.
Metadata/ — thumbnails and slicer data: plates, filament colours, print profiles (model_settings.config, project_settings.config, Slic3r_PE.config).
_rels/.rels and [Content_Types].xml — bookkeeping that tells programs which part is the model.

How to open a 3MF file

In the browser: use the 3MF viewer below — no install.
In a slicer: Bambu Studio, OrcaSlicer, PrusaSlicer, Cura and most manufacturer slicers open 3MF directly.
In CAD and 3D software: Fusion, Blender (with an add-on) and many others import 3MF, or convert it to OBJ or GLB first.

Project 3MF vs plain 3MF

A plain 3MF holds geometry, units and colours. A project 3MF from a slicer adds plates, filament assignments, modifiers and print settings — handy if you have the same slicer, confusing if you don't. You can turn a project into a plain 3MF or into STL here.

Open a 3MF file now

Frequently asked questions

What program opens 3MF files?

Any current slicer (Bambu Studio, OrcaSlicer, PrusaSlicer, Cura), many CAD tools, and online viewers like the one on this page.

Is a 3MF file safe to open?

A 3MF is a ZIP archive of XML and images; it doesn't contain programs. This viewer only reads geometry and metadata from it.

Can I convert a 3MF to STL?

Yes, use the 3MF to STL converter. You can export all objects, one plate or each object separately.