OFF to STL Converter
Convert a bare OFF geometry file to binary STL for 3D printing. Both formats are geometry-only, so nothing is lost. Runs in your browser.
Drag & drop your OFF file here
or click to browse
Supported Formats
Format Information
Source Format
OFF.off
OFF (Object File Format)
OFF is a minimal, human-readable geometry format from the Geomview project: a header line, a count line, then a list of vertex positions and a list of polygon vertex lists. There is deliberately nothing else in the specification.
What it carries: Vertex positions and face index lists, written out as triangles. No normals, no colours, no UVs, no materials, no textures and no animation.
Open a OFF file in the viewerTarget Format
STL.stl
STL (Stereolithography)
STL is an additive-manufacturing format from the 1990s: a flat list of triangles and nothing else. It has no concept of a scene, a material or a texture, which is why it is the lingua franca of 3D printing and also its most lossy interchange format.
What it carries: Triangle positions and, optionally, one facet normal per triangle. No UVs, no vertex colours, no materials, no node hierarchy, no animation.
Open a STL file in the viewerAbout this conversion
The bare minimum surface conversion. OFF vertices and faces become a binary STL with facet normals — the same geometry in the format every printer and mesh tool accepts.
Why convert OFF to STL
- Send bare geometry to a 3D printer or slicer.
- Hand a minimal geometry file to a mesh-repair or analysis tool that only reads STL.
- Produce a compact, dependency-free shape file for sharing.
What happens during the conversion
Geometry
The vertex positions and face list are triangulated and written as a binary STL with one facet normal per triangle. There is no hierarchy to flatten, because OFF has none.
Materials and textures
None, and none are lost — OFF has no materials, colours, UVs or normals either. Both formats are geometry-only.
Common use cases
- Preparing bare geometry for printing.
- Running STL-based mesh repair or analysis.
- Sharing a minimal shape file with anyone.
Limitations of this conversion
- No colour, material, texture or UV data exists in either format, so appearance must be added later.
- Everything is merged into a single triangle list.
- STL carries no unit metadata, so confirm the scale in your slicer.
How to convert OFF to STL
Three steps in the browser. Nothing is uploaded to a server, so an unwieldy file is limited only by your own device's memory.
Upload your .off
The plain-text OFF file is read directly, and one facet normal per triangle is derived from the face winding.
Convert to STL
Vertices and faces are triangulated and written as a binary STL with facet normals.
Check the scale in your slicer
STL has no unit field, so confirm the OFF file's coordinates are in millimetres before printing.
Related tools and formats
Other conversions from this format
Check the file in a viewer
Frequently Asked Questions
Questions people ask when turning OFF files into STL.
Looking for a different direction? See every supported conversion.