Convert 3MF
to SLDPRT.

Updated 2026-10-19

To convert 3MF (.3mf) to SLDPRT (.sldprt), drop the file below and download the result, in the browser with nothing installed. The mesh comes back as a SLDPRT solid with real surfaces: a round hole becomes one cylindrical face.

2 solid-geometry conversions a day with no account. No card, no install.

No account needed
Drop a 3MF file.3mf · up to 200 MB

On our servers. No account: deleted within 24 hours. Signed in: kept until you delete them. Never shared or used for training.

ResultSurfaces recovered

Planes, cylinders, cones and spheres are rebuilt as true surfaces where the triangles fit them, and freeform regions as smooth patches, in a closed solid that mates, measures and cuts like modelled geometry. Where they cannot be rebuilt the body is faceted instead, and every conversion says which of the two you got.

The STEP as a faceted converter writes it: 524 flat faces, one per triangle.

One face per triangle · 524 faces. Each hole is a ring of flat strips you cannot select or measure.

The STEP from MeshWeave: 10 faces, 7 planes and 3 cylinders.

MeshWeave · 10 faces: 7 planes and 3 cylinders. The hole measures Ø12.00 mm.

The same 524-triangle STL, converted both ways and coloured one shade per face. A synthetic test part, run through the converter, not drawn.

Surfaces are only as accurate as the mesh they come from, and there is no feature history.

HowThree steps
  1. Drop your .3mf file above — up to 200 MB without an account.
  2. SLDPRT is already selected as the output.
  3. Download the .sldprt. Without an account, files are deleted within 24 hours; signed in, they are kept until you delete them.
FormatsWhat you are holding

3D Manufacturing Format file (.3mf)

3MF was designed to replace STL for 3D printing. It records units, colour and material, keeps multiple objects separate, and is compressed. Bambu Studio, PrusaSlicer, Cura and Windows all read it. The shape is still a triangle mesh.

You are printing and want units, colour and part structure to survive the handover.

SOLIDWORKS part file (.sldprt)

A SLDPRT file is a single SOLIDWORKS part: the exact solid — true planes, cylinders and splines — plus its feature history, sketches, material and custom properties. It is proprietary, so nothing else on your machine may open it. Assemblies are SLDASM files. One SLDPRT can hold several bodies, and those should stay separate when converting.

You were sent a SLDPRT, do not have SOLIDWORKS, and need the geometry in something your CAD system, slicer or mesher opens.

Questions6 answered
Is the 3MF to SLDPRT converter free?
Yes. 2 solid-geometry conversions a day with no account, of 5 in total. A free account converts 4 solid files a day and adds 25 credits. No card.
Does the SLDPRT result have real curves, or flat facets?
The mesh comes back as a SLDPRT solid with real surfaces: a round hole becomes one cylindrical face. Planes, cylinders, cones and spheres are rebuilt as true surfaces where the triangles fit them, and freeform regions as smooth patches, in a closed solid that mates, measures and cuts like modelled geometry. Where they cannot be rebuilt the body is faceted instead, and every conversion says which of the two you got. Surfaces are only as accurate as the mesh they come from, and there is no feature history.
Will the SLDPRT file open in Fusion 360, Inventor or Onshape?
Yes. SLDPRT is read directly by Fusion 360, Inventor, Onshape, SOLIDWORKS, Creo, NX and FreeCAD. It usually arrives as a solid body with true surfaces, without feature history, and the conversion says when it came back faceted instead.
How big a file can I convert?
To a mesh format like STL: 300 MB with a free account, 200 MB without one. To STEP, Parasolid or SLDPRT: 140 MB, because rebuilding a solid takes about twice the memory of writing a mesh. Maker and Studio convert up to 830 MB and 380 MB — a large conversion on a paid plan gets the server to itself.
Is it safe to upload my 3MF file?
Files travel encrypted and are processed by machine on our own servers — no third parties, no ads or trackers, no AI training.
Is my 3MF file deleted after converting?
Without an account, the upload and the result are deleted within 24 hours. With an account, both stay in your files until you delete them; deleted files leave our servers within 24 hours.
Beyond convertingSame file, four workspaces

Keep the part open: fill it with a lattice, check it with FEA, texture a surface, or slice it into cut-ready sheets. These workspaces are in early access — create an account, then apply from inside the app.

Create free account See pricing

AlsoOther ways in
MoreRelated conversions

Going the other way? Convert SLDPRT to 3MF.

SOLIDWORKS® is a registered trademark of Dassault Systèmes SolidWorks Corp. MeshWeave is an independent tool and is not affiliated with, endorsed by, or sponsored by Dassault Systèmes.