Convert 3DM
to STL.

Updated 2026-10-19

To convert 3DM (.3dm) to STL (.stl), drop the file below and download the result, in the browser with nothing installed. The Rhino geometry is triangulated into a STL mesh.

5 conversions a day with no account. No card, no install.

No account needed
Drop a 3DM file.3dm · 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.

ResultTessellated

NURBS surfaces and extrusions are tessellated, existing meshes taken directly and SubD objects meshed from their smooth surface, in millimetres, one object per Rhino object where the STL format keeps objects apart. Trimmed boundaries and holes keep their silhouettes.

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

Rhinoceros 3D model file (.3dm)

A 3DM file is a Rhino model. Rhino is a NURBS modeller, dominant in industrial design, jewellery, marine and architecture. A 3DM can mix exact breps, surfaces, meshes and curves on layers; polysurfaces and extrusions convert exactly, and mesh objects come along: as meshes in a mesh format, rebuilt as true surfaces in a solid one.

A designer works in Rhino and engineering or manufacturing needs the shape in a format their system reads.

STL file (stereolithography) (.stl)

STL is the lingua franca of 3D printing: a flat list of triangles. No unit, colour, material or history — a cylinder is a fan of flat strips. The missing unit is the classic cause of scale accidents. Every slicer and mesh tool reads it.

You are printing, meshing or sending to a bureau — where triangles are what is wanted.

Questions7 answered
Is the 3DM to STL converter free?
Yes. 5 conversions a day with no account and no card. A free account raises the limit and adds 25 credits.
Do I need Rhino installed?
No. The 3DM file is read in the browser with nothing installed and no Rhino licence.
How accurate is the STL mesh?
The Rhino geometry is triangulated into a STL mesh. NURBS surfaces and extrusions are tessellated, existing meshes taken directly and SubD objects meshed from their smooth surface, in millimetres, one object per Rhino object where the STL format keeps objects apart. Trimmed boundaries and holes keep their silhouettes.
Will the STL file be the right size?
It is written in millimetres. STL records no unit, so choose millimetres if your slicer asks. 3MF records units in the file.
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 3DM 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 3DM 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 STL to 3DM.

Rhinoceros® and Rhino® are registered trademarks of Robert McNeel & Associates. MeshWeave is an independent tool and is not affiliated with, endorsed by, or sponsored by Robert McNeel & Associates.