Convert Q3O to OFF
Free, in your browser, with nothing uploaded. Drop your .q3o file in and take the .off away.
Drop your Q3O file here
.q3o in, .off out
Choose filesNothing is uploaded No account, no email No file size limit
How to convert Q3O to OFF
- 01
Add your .q3o file
Drag your Quick3D Object file onto the drop zone, or click it to browse. Nothing is uploaded: it is read where it already sits.
- 02
Check the preview
The model is parsed on your machine and drawn in the viewport, so a wrong axis or a missing texture shows up before you commit rather than downstream.
- 03
Save the .off file
Press convert. The Object File Format file is written in the tab and lands in your downloads folder. No link, no expiry, no account.
What carries over, and what does not
A format conversion is a translation, and translations lose things. Here is what actually happens when a Q3O file becomes an OFF file.
| Data | Q3O | OFF | Survives |
|---|---|---|---|
| Geometry | Yes | Yes | Yes |
| Materials & colour | Yes | No | Dropped |
| Texture maps | Yes | No | Dropped |
| Animation & rigs | No | No | n/a |
| Scene hierarchy | Yes | No | Dropped |
Expect to lose
- OFF has no concept of texture coordinates or image maps; the model comes out untextured.
- The scene hierarchy is flattened: separate objects in the Q3O file are merged into one mesh.
None of this is a defect in the conversion; it is what OFF is specified to hold. If you need the missing data, convert to GLB instead, which carries geometry, PBR materials, textures and animation in a single file.
What our OFF writer puts in the file
Geometry only, which is all OFF holds. A model with more than one material comes out as COFF with a colour on each face.
About Quick3D Object
Q3O and its scene variant .q3s are the native formats of Quick3D, a Windows utility built for viewing and converting between the many competing 3D formats of its era. Files in it are usually the by-product of somebody else’s conversion.
Commonly seen in: Quick3D, legacy conversion pipelines. More on the Q3O format page.
About Object File Format
OFF is about as simple as a mesh format gets: the word OFF, three counts, a list of vertices, and a list of faces indexing them. It comes out of Princeton’s Shape Benchmark and the geometry-processing world, which is where you still meet it: segmentation datasets, computational geometry papers and course assignments almost always ship OFF.
Commonly seen in: Princeton Shape Benchmark, MeshLab, CGAL, Geomview, academic datasets. More on the OFF format page.
How the conversion works
When you drop a file in, the bytes are handed to a parser compiled to run in your browser. The Q3O data is decoded into an in-memory scene graph of meshes, materials and transforms, which is what the preview is drawing. Pressing convert walks that scene graph back out through a OFF writer and hands you the resulting bytes as a download.
The whole round trip is local. The page itself is static: it is delivered once and then does its work offline. That is why the privacy claim is checkable rather than a promise.
Q3O to OFF: common questions
Is my Q3O file uploaded anywhere?
No. The file is read by code running inside this browser tab and never crosses the network. You can prove it by disconnecting from the internet before you convert, the page keeps working, or by watching the Network tab in your browser's developer tools while you drop a file in.
How large a Q3O file can I convert?
There is no server-side limit because there is no server. The practical ceiling is your own machine's memory: a browser tab can usually handle models up to a few hundred megabytes. Very dense scans or scenes with millions of triangles will take a few seconds and a lot of RAM.
Why does my converted OFF file look untextured?
OFF stores geometry only; it has no way to record materials or texture maps. If you need the surfacing to survive, convert to GLB or glTF instead.
Does it cost anything?
No. There is no fee, no account, no watermark and no per-file limit. Since the conversion runs on your hardware rather than ours, serving this page costs about as much as serving a blog post.
Does it work on a Mac, on Windows or on a phone?
All of them. There is nothing to install: any browser with WebGL 2 will do, which covers current Chrome, Edge, Firefox and Safari on desktop, and Safari and Chrome on mobile. A phone has less memory than a laptop, so a very heavy scene may be the one thing it cannot finish.
Related conversions
Other things to do with the same file.
From Q3O:
Other ways to get to OFF:
Or do something else with it: