Free online 3DM viewer
Drop a Rhino .3dm to look at it without a Rhino licence: meshes, curves and points, with object and layer counts and the document’s units. It is read in your browser and not uploaded.
How to open a 3DM file
- Drop the .3dm on the viewer. The first time, the page fetches Rhino's own file reader (rhino3dm, about 2.7 MB) from this site; after that it is cached.
- Orbit and zoom. Rhino is Z-up and so is the view; objects on layers that were hidden when the file was saved stay hidden.
- Read the panel: how many Rhino objects of each kind, how many layers, the model unit system, and the bounding box in those units. A note appears for any surface that could not be drawn.
What a .3dm holds
.3dm is the file format of Rhinoceros, the NURBS modeller from McNeel, and of the open-source openNURBS library that reads and writes it. Unlike the mesh formats on the neighbouring pages it stores exact geometry — NURBS curves and surfaces, polysurfaces, extrusions, SubD — alongside ordinary meshes, points and annotations, organised in layers, with a declared unit system.
The file is parsed here by rhino3dm, McNeel’s own build of openNURBS for the web, so reading is as faithful as it gets outside Rhino. Drawing is another matter: a browser draws triangles, and the page does not tessellate NURBS itself. A surface is shown through the render mesh that Rhino caches in the file when the model has been displayed in a shaded view.
For avatars: this is a CAD format with no skeleton or skin weights. A Rhino model can be a prop or an accessory once it is meshed and exported, never an avatar on its own.
What this viewer does not do
A surface or polysurface saved without a render mesh is not drawn; the panel counts those and says how to fix it in Rhino. There are no layer toggles, no measuring, no section cuts and no editing. Block instances, annotations, dimensions and hatches may be missing or simplified. Materials are approximated from the Rhino material’s colour and basic settings; a texture is used only if you drop the image file alongside, since the .3dm stores a path to it on the author’s disk. Grasshopper definitions (.gh) are a different file type and are not read.
Frequently asked questions
How can I open a .3dm file without Rhino?
Drop it here. The page uses rhino3dm, the reader McNeel publishes, compiled to WebAssembly, so the file is parsed on your own machine by the same code family Rhino uses. It shows the model; it does not replace Rhino for editing.
Some of my surfaces are missing. Why?
They have no render mesh in the file. Rhino stores NURBS surfaces as mathematics and adds a triangle mesh for display only after the object has been shown shaded. Open the file in Rhino, switch a viewport to Shaded or Rendered, save, and the surfaces appear here. Files saved with “Save small” have their render meshes stripped on purpose.
Which Rhino versions are supported?
The reader is openNURBS from the Rhino 8 generation, which opens files written by Rhino 8 and by every earlier version. A file from a newer Rhino than the reader knows may be refused; saving it as Rhino 8 or earlier settles that.
Does it show the real dimensions?
Yes, as far as the file states them. The document's model unit system — millimetres, inches, metres and so on — is read and shown, and the bounding box is given in those units. The ground grid's squares are a round number of the same unit.
Is my file uploaded?
No. Both the file reader and the drawing run in your browser. The reader itself is served from this site rather than a third-party CDN, so no other company sees that you opened a file.
Can it open Grasshopper files?
No. A .gh or .ghx file is a Grasshopper definition, a program that generates geometry, and needs Rhino to run. Bake the geometry in Rhino and save a .3dm to view it here.
Can a Rhino model be used as a VTuber avatar or prop?
As a prop, after exporting a mesh (OBJ, FBX or glTF) from Rhino. As an avatar, no: a .3dm has no bones, and a character would need to be retopologised and rigged in a tool made for that before a VRM could be made.
Exported a mesh from Rhino?
Rhino exports OBJ, STL, 3MF and FBX, and each has a viewer here: the OBJ viewer, the STL viewer, the 3MF viewer and the FBX viewer. They are the quickest way to check what the export actually contains before sending it on.