Your objects. Together or separately.

A 3MF can place the same mesh more than once. This tool exports placed build instances, so a repeated part keeps every selected placement.

Choose the output that fits your next step

Export separate objects in four steps

1. Open your 3MF in the converter.
2. Review the Objects tab. All exportable placed instances are selected initially.
3. Uncheck anything you do not need. Unselected geometry fades in the preview.
4. Choose “Download separate files.” Extract the ZIP and import the STL files as millimeters.

What counts as an object here?

Each list item represents one printable build instance. If that instance references a component assembly, the components stay together in its STL. A single instance containing two disconnected shells still produces one file. This tool does not split by connected shell, material, or arbitrary mesh resource.

Unused mesh resources are not added to the output. Non-printable build items are excluded and reported. A missing object or circular reference stops the conversion instead of silently dropping a piece.

Are relative positions preserved?

Yes. Component and build transforms are applied to the exported vertices. We do not center each object or move it to the bed. For our two-instance sample, the first cube spans X = 0–10 mm and the second spans X = 30–40 mm. Each contains 12 triangles.

When should I use the source slicer?

If you need modifier volumes, support parameters, paint assignments, or project editing, open the original 3MF in its originating slicer. For a rejected file, consult the supported subset and error guide. Converting an STL copy does not transfer those project features.