Novus Convert
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Vector & CAD format

OFF converter

An .off file is about the simplest polygon mesh format that exists: the word OFF, a line giving the vertex, face and edge counts, then the vertex coordinates and then the faces, each written as a vertex count followed by that many indices. There are no materials, no transforms and no scene graph — only geometry.

Private for supported formats — processed in your browser

Convert supported files

Runs on your device

Drop OFF files here

Batch files can each use a different output. Nothing uploads for local conversions.

Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.

Where OFF comes from

OFF came out of the Geomview visualisation system developed at the Geometry Center at the University of Minnesota around 1990. Geomview itself is long retired, but the format survived because it is trivial to write by hand and trivial to parse, which made it the default interchange format for computational-geometry research. Princeton's shape benchmarks distribute in OFF, and most mesh-processing libraries still read it.

How OFF works

  • Plain ASCII. The header line is literally OFF, optionally COFF or NOFF when colours or normals are present.
  • Line two gives vertex count, face count and edge count — the edge count is conventionally 0 and is ignored by every reader.
  • Faces are arbitrary polygons, written as an n followed by n vertex indices, so quads and n-gons are legal and must be triangulated by the reader.
  • Indices are zero-based, unlike OBJ, which is the single most common source of off-by-one bugs when converting between the two.
  • There is no unit, no up-axis and no coordinate-system declaration, so scale and orientation are conventions rather than data.

When to use OFF

  • Computational-geometry and mesh-processing research, where the format's simplicity is the point
  • Hand-authoring a small test mesh without a modelling tool
  • Moving raw triangle soup between academic tools that share no other format
  • Converting a research mesh into STL or GLB for printing or viewing

Strengths and limitations

Strengths

  • Almost impossible to get wrong — the parser fits on a page
  • Human-readable and diffable, so a geometry change shows up in version control
  • Supports arbitrary polygons, not just triangles

Limitations

  • No materials, textures, normals or scene structure in the base variant
  • No units or up-axis, so orientation and scale must be agreed out of band
  • ASCII, so files are several times larger than an equivalent binary mesh

Compatibility

MeshLab, Blender (via add-on), CGAL, libigl, Open3D and most academic mesh libraries read OFF. No operating system or browser previews it natively. Novus Convert reads it locally and converts to STL, OBJ, 3MF, GLB, glTF, PLY and USDZ; polygons are triangulated on the way out because every one of those targets expects triangles.

None. OFF carries geometry only — no names, no units, no authorship.

Convert OFF to another format