Convert Rhino 5 to Rhino 3

Rhino 3 cannot open files saved in the newer Rhino 5 format. RhinoFileConverter re-writes your .3dm file using the official OpenNURBS libraries so it opens natively in Rhino 3 — geometry, layers, and object structure preserved.

Files will be converted to Rhino 3 (if compatible).

Why convert Rhino 5 files to Rhino 3?

Rhino 3 users can't open .3dm files saved by Rhino 5 — the format isn't forward-compatible. Rather than upgrading licenses or emailing colleagues to re-save files, convert them here in seconds.

  • Open Rhino 5 files in Rhino 3 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. 1

    Upload your Rhino 5 .3dm file (drag & drop or browse)

  2. 2

    We detect the file version instantly from the file header

  3. 3

    Click Convert — the file is rewritten in Rhino 3 format using the official OpenNURBS libraries

  4. 4

    The converted file downloads automatically

Rhino 5 to Rhino 3 — FAQ

Can Rhino 3 open Rhino 5 files?

Not directly. Rhino file formats are not forward-compatible: Rhino 3 cannot read .3dm files saved by Rhino 5. Converting the file to the Rhino 3 format with RhinoFileConverter solves this.

Will my geometry change when converting Rhino 5 to Rhino 3?

NURBS geometry, curves, meshes and layers are preserved. Features introduced after Rhino 3 (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.