Convert OFF to PLY
Free OFF to PLY converter that runs in your browser. See real dimensions before you download.
How to convert OFF to PLY
- Drop your OFF file onto the converter — it opens in your browser, nothing is uploaded.
- Check the preview and the dimensions in mm; fix units or the up axis in “Units & orientation” if the size or orientation looks wrong.
- Choose PLY as the output and click Convert. Several files download as one ZIP.
What carries over from OFF to PLY
| OFF | PLY | Result | |
|---|---|---|---|
| Colour / materials | No | Yes | — |
| Textures | No | No | — |
| Units stored in file | No | No | Numbers in mm |
| Separate parts | No | No | — |
| Usual up axis | Z | Z | Unchanged |
About OFF files
OFF, the Object File Format, was defined for Geomview, an interactive geometry viewer developed at the Geometry Center at the University of Minnesota in the 1990s. A file is plain text. The first line holds the keyword OFF, the second gives the counts of vertices, faces and edges, then each vertex appears as three coordinates and each face as a vertex count followed by index numbers. Variants add colour (COFF), normals (NOFF) or texture coordinates (STOFF) through prefixes, and colour is optional at the end of each line. The simplicity made it a favourite in computational geometry, and benchmark sets such as ModelNet used it for machine-learning research on shape classification. CGAL and libigl read and write it directly. It has no units, materials or scene structure, so it is rarely a printing format, but converting it is common.
About PLY files
PLY was developed in the mid-1990s by Greg Turk and colleagues at the Stanford Graphics Lab to store data from 3D scanners, and the Stanford Bunny and Happy Buddha models made it famous. A PLY file starts with a text header that declares elements, such as vertex and face, and the properties each element has. The body then follows in ASCII, binary little-endian or binary big-endian. Because properties are declared in the header, a file can carry any extra per-vertex data: normals, colour channels, intensity, confidence or custom scalars. This flexibility made PLY a standard output for scanners, depth cameras, photogrammetry and point-cloud tools. It can store a point cloud with no faces at all, or a polygon mesh. It does not define units or a scene structure.
3D printing notes
Few slicers open OFF directly, so the usual job is converting a research or dataset mesh into STL or 3MF. Dataset meshes such as those in ModelNet are often unit-less, normalised to a small box and not designed for printing, so they can be scaled to a size of one unit and have thin shells or holes. Set the printed size deliberately, then run a repair. MeshShift reads and writes OFF in the browser, shows real dimensions, lets you rescale, and converts to STL, 3MF, OBJ, GLB or PLY. Its print check finds holes and flipped normals and can rebuild a closed solid at the same size before you slice.
Frequently asked questions
Is this OFF to PLY converter free and private?
Yes. The conversion runs in your browser with JavaScript and WebAssembly, so your OFF file is never uploaded to a server. There is no sign-up, no watermark and no daily limit; very large files are limited only by your device's memory.
What is an OFF file used for?
OFF is a simple mesh format used mainly in geometry processing and machine-learning research. Datasets like ModelNet ship as OFF because the format is easy to parse. It is a plain text list of vertices and faces.
Does PLY store colour?
Yes, usually as red, green and blue values attached to each vertex, not as a texture image. Colours are smooth across triangles, which suits scans. Many slicers ignore vertex colour, so use 3MF or another format if you need to preserve it for printing.