Convert 3DM to GLB
Convert 3DM to GLB in your browser. The conversion runs on this page and the file never leaves your computer.
Result
Before you convert: what this keeps and what it destroys
Preserved
- The shape, to within the tessellation tolerance
- Overall dimensions and proportions
- Watertightness, where the input is watertight
- Colour
- Separate parts and their positions
Destroyed
- Exact curves and surfaces, replaced by triangles
- The feature tree and any parametric history
- A recorded unit: GLB stores none
Why people convert 3DM to GLB
Putting a Rhino model on a product page, in a browser viewer, or into AR on Android.
This is a good pairing. GLB keeps object colours as PBR base colours and keeps a real node hierarchy, so a jewellery piece or a piece of furniture arrives as its component parts rather than one merged mass, and a viewer can let people click them.
The scale changes. 3DM declares its unit, so this conversion knows exactly what it is starting from, and every coordinate is converted into glTF's metres. A ring modelled at 20 mm becomes 0.02 in the file, which is correct and looks alarming the first time you open the JSON.
What you get
You get a binary GLB file containing triangles. The reader tessellates supported surfaces or uses saved render meshes where required by the source format. Inspect curved faces at the intended output size. The triangle count depends on the model and the reader's meshing settings.
The output uses metres, as required by the glTF specification.
Carried across: supported base or vertex colour, the supported part structure.
The conversion runs in your browser. Your file stays on your computer and is not uploaded.
What to check afterwards
- 3DM declares its unit in the file. Check the output dimensions in the receiving application, especially when its import settings can override the unit.
- Curves become facets. 3DM stores exact surfaces, so a hole is a cylinder with a radius. GLB stores triangles, so that cylinder becomes a many-sided prism. Look at curved faces in the result at the size you intend to make the part.
- Coordinates are stored as 32-bit floats. For a part measured in millimetres that's far finer than any machine tolerance. For a model spanning hundreds of thousands of units it isn't.
If you need something this conversion cannot give you
If you need editable CAD geometry, don't convert at all. Open the 3DM file directly in FreeCAD, Fusion, Onshape or SolidWorks. Every mesh format destroys the exact surfaces, and no later conversion brings them back.
Going the other way
This site reads 3DM but does not write it. For the reverse conversion, use an application that can export 3DM.
How we know this conversion works
This pair was checked against 3 files from the test corpus on 2026-09-04. Each run parses its own output back in and compares the bounding box, the triangle count and, for closed solids, the volume against the input.
A pair that fails those checks doesn't get a page. That's why this site lists 120 conversions and not the several hundred a format-times-format grid would suggest.