Convert Rhino 4 to Rhino 2
Rhino 2 cannot open files saved in the newer Rhino 4 format. RhinoFileConverter re-writes your .3dm file using the official OpenNURBS libraries so it opens natively in Rhino 2 — geometry, layers, and object structure preserved.
Files will be converted to Rhino 2 (if compatible).
Why convert Rhino 4 files to Rhino 2?
Rhino 2 users can't open .3dm files saved by Rhino 4 — the format isn't forward-compatible. Rather than upgrading licenses or emailing colleagues to re-save files, convert them here in seconds.
- Open Rhino 4 files in Rhino 2 without upgrading your license
- Official OpenNURBS write pipeline — the same code Rhino uses
- NURBS surfaces, curves, meshes, layers and blocks preserved
- Runs in seconds, right in your browser — files stay private
- No plugins or software installation required
- Works on Windows, macOS and Linux
How it works
- 1
Upload your Rhino 4 .3dm file (drag & drop or browse)
- 2
We detect the file version instantly from the file header
- 3
Click Convert — the file is rewritten in Rhino 2 format using the official OpenNURBS libraries
- 4
The converted file downloads automatically
Rhino 4 to Rhino 2 — FAQ
Can Rhino 2 open Rhino 4 files?
Not directly. Rhino file formats are not forward-compatible: Rhino 2 cannot read .3dm files saved by Rhino 4. Converting the file to the Rhino 2 format with RhinoFileConverter solves this.
Will my geometry change when converting Rhino 4 to Rhino 2?
NURBS geometry, curves, meshes and layers are preserved. Features introduced after Rhino 2 (for example newer annotation styles or SubD in pre-7 formats) are translated to their closest older equivalent, exactly as Rhino's own "Save As" would do.
Is my file uploaded to a server?
No. The conversion runs entirely in your browser using the official OpenNURBS WebAssembly build. Your model never leaves your computer.
Is there a file size limit?
Free conversions support files up to 25 MB. Paid plans raise the limit to 100 MB and 250 MB.