.off File Extension

What kind of file is a .off?

OFF is a compact text format for polygon meshes. Its header identifies the format, followed by counts for vertices, faces, and edges; subsequent records list coordinates and face indices. Variants add conventions for colors or higher-dimensional data, so applications should validate the header. The suffix normally uses the model/x-off MIME type.¹

How do I open a .off?

MeshLab and CGAL tools can import OFF Object File Format files on desktop systems; Blender is another practical choice for conversion when its importer supports the asset. Keep any companion resources with the model, and validate scale, winding order, and whether the surface is closed before sending it to a print or CAD workflow.

Export to GLB for a scene package with richer materials and animation, or to 3MF for additive manufacturing when package metadata matters. Renaming a suffix does not convert a file.

Poly support for .off

Poly previews supported geometry, makes the filename searchable, and provides visual similarity for supported 3D content. Available geometry metadata appears in the details panel. An optimized rendition of the 3D object or scene is provided to the agent, allowing compact yet information-rich multimodal interaction with 3D files.

Keep the original source when exact topology, custom attributes, or companion-file relationships matter.

History and alternatives

OFF became associated with the Geomview and computational-geometry communities as a simple way to exchange polygonal objects. Its small vocabulary is easy to inspect, but it intentionally carries less scene information than modern asset formats. ¹

Use glTF or GLB for interactive scenes, 3MF for manufacturing packages, and STL when a simple triangular surface is enough. Convert in a 3D application and verify the exported model rather than relying on a filename change.