Convert COB to AMF
Free, in your browser, with nothing uploaded. Drop your .cob file in and take the .amf away.
Drop your COB file here
.cob in, .amf out
Choose filesNothing is uploaded No account, no email No file size limit
How to convert COB to AMF
- 01
Add your .cob file
Drag your Caligari trueSpace 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 .amf file
Press convert. The Additive Manufacturing 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 COB file becomes an AMF file.
| Data | COB | AMF | Survives |
|---|---|---|---|
| Geometry | Yes | Yes | Yes |
| Materials & colour | Yes | Yes | Yes |
| Texture maps | Yes | No | Dropped |
| Animation & rigs | No | No | n/a |
| Scene hierarchy | Yes | Yes | Yes |
Expect to lose
- AMF has no concept of texture coordinates or image maps; the model comes out untextured.
None of this is a defect in the conversion; it is what AMF 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 AMF writer puts in the file
Geometry, per-volume material colour and the unit, written as plain XML rather than the zipped form, because half the readers that claim AMF support take only the plain one.
About Caligari trueSpace Object
COB is Caligari trueSpace’s object format, from a modeller that put 3D on ordinary PCs in the 1990s and was eventually given away for free by Microsoft. Its .scn scene variant is handled by the same reader. Mostly of archive interest now, but a lot of early amateur 3D work exists nowhere else.
Commonly seen in: trueSpace, 1990s 3D archives. More on the COB format page.
About Additive Manufacturing Format
AMF is the ISO/ASTM standard that took the first run at replacing STL: XML-based, unit-aware, with support for graded materials, colour and curved triangles that subdivide smoothly instead of faceting. It largely lost the format race to 3MF in practice, but it remains the standardised choice and turns up in research and industrial additive-manufacturing workflows.
Commonly seen in: Slic3r, PrusaSlicer, Netfabb, academic and industrial AM tooling. More on the AMF 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 COB 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 AMF 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.
COB to AMF: common questions
Is my COB 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 COB 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 AMF file look untextured?
AMF 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 COB:
Other ways to get to AMF:
Or do something else with it: