OFF to STEP Converter
FileFlip converts OFF to STEP entirely inside your browser, using Assimp compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an OFF file to STEP?#
- Drop your OFF file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to STEP and the conversion starts on its own. FileFlip downloads 11.2 MB of WebAssembly the first time and nothing after that, then runs Assimp on your own machine.
- Save the STEP file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting OFF to STEP lose quality?#
Not in the sense of pixels or samples. Converting OFF to STEP rebuilds the file in STEP's own model rather than re-encoding it, so everything STEP can represent comes through exactly and anything it cannot has to be dropped. Expect the geometry to be exact, and anything the target has no place for, such as a rig, to be left behind.
Is it safe to convert OFF files online?#
Yes, because nothing is uploaded. FileFlip converts OFF files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What OFF to STEP actually does to the file#
Converting OFF to STEP runs on Assimp, downloads 11.2 MB of WebAssembly the first time and nothing after that, rebuilds the file in the target's own model, and drops skeleton and animation.
| Engine | Assimp |
|---|---|
| Conversion path | One step: OFF → STEP |
| Downloaded to your browser | 11.2 MB, once, then cached by your browser |
| Quality | Rebuilt in the target's model |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Materials | Sometimes | Survives for some files and not others. |
| Textures | Sometimes | Survives for some files and not others. |
| Skeleton and animation | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- if the source carries a skeleton or animation, this target has no place to store it
What is an OFF file?#
An OFF file is plain text written for the Geomview viewer built at the University of Minnesota's Geometry Center, starting with the word OFF and a line giving the vertex and face counts before listing each vertex's coordinates and each face's vertex indices in order.
Use OFF when a mesh needs to move between computational geometry tools or research code that already expects the format.
Convert OFF to OBJ or STL when the mesh needs to open in mainstream 3D software, since OFF support outside academic tools is limited.
What is an STEP file?#
An STP file holds a STEP product model in ISO 10303's plain-text exchange syntax, encoding exact boundary-representation solids, surfaces and curves rather than a triangulated mesh.
Use STEP whenever exact CAD geometry, not an approximated mesh, needs to move between two different CAD systems.
Convert a STEP file to a mesh format like STL or OBJ once the model is finished and only needs to be viewed, rendered or 3D printed rather than edited as a solid.
OFF to STEP questions people ask#
What is an OFF file?
An OFF file is a minimal 3D mesh format: a vertex count, a face count, a list of vertex coordinates and a list of faces given as vertex indices, with nothing else. It comes from Geomview, the visualisation tool built at the University of Minnesota's Geometry Center, and shows up throughout computational geometry research and teaching material.
What software opens OFF files?
MeshLab and Geomview both open OFF files directly, and most computational geometry libraries such as CGAL can read and write it. Outside of research and mesh-processing tools, general-purpose 3D software rarely supports it natively.
Does an OFF file support color?
Yes, an OFF file can carry an optional RGBA colour value on each vertex or each face, appended right after its coordinates or indices. It's the one piece of surface information the format supports beyond raw geometry.
What does STP stand for?
STP is the file extension for STEP, the Standard for the Exchange of Product model data, formally ISO 10303. It's the neutral format mechanical CAD systems use to hand solid models to each other.