# 3MF to STL converter

> Convert any 3MF file to STL in your browser, including multi-part Bambu Studio and OrcaSlicer projects. Real millimetre size, free, no upload.

Source: https://freestlviewer.com/3mf-to-stl/  
Updated: October 22, 2026

Turn a .3mf — including Bambu Studio and OrcaSlicer projects — into an STL any slicer or service can read. Converted in your browser, never uploaded. The tool is interactive: open https://freestlviewer.com/3mf-to-stl/ and drop a file onto the page.

## When you need STL from a 3MF

3MF is the better printing format, but STL is still what everything accepts:
older slicers, online print services, CNC and CAM tools, scripts and many
model-repair tools. Converting gives you a file anyone can open.

## Bambu Studio and OrcaSlicer projects

Bambu Studio and OrcaSlicer save each object's mesh in its own file inside the
3MF and place them with the 3MF Production extension. Converters that only
read the simplest 3MF layout produce an empty or scrambled STL from these. This
converter reads the package the way the slicer wrote it:

- every object and component is followed across files and transformed to its
  saved position;
- the declared unit is converted to millimetres;
- a sliced `.gcode.3mf` print job is recognised and reported, instead of
  producing an empty file.

## What changes in the STL

| In the 3MF | In the STL |
| --- | --- |
| Several objects with names | One merged mesh |
| Plates and object positions | Positions kept; all plates in one file |
| Units (usually mm) | Millimetres, unlabelled |
| Colours and filament choices | Dropped |
| Supports, modifiers, slicer settings | Dropped |

If you need each object as its own STL, export them individually from the
slicer, or load the merged STL and use **Split to objects**.

## Keep the colours? Stay in 3MF

If the receiver can read 3MF, sending the 3MF is usually better: smaller, with
units and colours. Choose **3MF** above to rewrite a project as a clean,
single-object 3MF that keeps its standard colours.

## On a phone

The converter works in a phone browser; the STL lands in Downloads or Files.
The Mes3D app for iPhone, iPad, Mac and Android opens 3MF projects directly and
exports STL, OBJ or 3MF after measuring, cutting or resizing.

## Frequently asked questions

### How do I convert a Bambu Studio 3MF to STL?

Drop the project .3mf onto this page and click Convert and download with STL selected. Every object in the project is placed where Bambu Studio had it and written as one STL in millimetres. You do not need Bambu Studio installed.

### Why does my 3MF fail to convert?

If it is a sliced print job (often named .gcode.3mf), it contains toolpaths rather than the model. Open the project file saved with File > Save Project in your slicer and convert that instead.

### Are colours kept when converting 3MF to STL?

No — STL cannot store colour. The geometry is converted completely. Bambu and Orca keep painted AMS colours in their own project data, which no STL can carry.

### Will the STL be the right size?

Yes. 3MF records its unit, and the converter writes the STL in millimetres at the model's real size.