Convert VTK to 3MF
Free, in your browser, with nothing uploaded. Drop your .vtk file in and take the .3mf away.
Drop your VTK file here
.vtk in, .3mf out
Choose filesNothing is uploaded No account, no email No file size limit
How to convert VTK to 3MF
- 01
Add your .vtk file
Drag your Visualization Toolkit 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 .3mf file
Press convert. The 3D 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 VTK file becomes a 3MF file.
| Data | VTK | 3MF | Survives |
|---|---|---|---|
| Geometry | Yes | Yes | Yes |
| Materials & colour | No | Yes | n/a |
| Texture maps | No | Yes | n/a |
| Animation & rigs | No | No | n/a |
| Scene hierarchy | No | Yes | n/a |
This is a comparatively lossless pairing: 1 of the five categories above are supported by both formats, so most of what is in your VTK file has somewhere to go in the 3MF file.
About Visualization Toolkit
VTK legacy files come out of the Visualization Toolkit and the applications built on it, most visibly ParaView. They are the standard container for simulation output, finite-element meshes and medical imaging surfaces, carrying arbitrary scalar and vector fields attached to points and cells. Converting one extracts the surface geometry so it can be opened in ordinary 3D software.
Commonly seen in: ParaView, VTK, FEA and CFD post-processing, medical imaging tools. More on the VTK format page.
About 3D Manufacturing Format
3MF is what STL should have been. Built by the 3MF Consortium as a zipped XML package, it records units, colours, materials, per-object print settings and the arrangement on the build plate, and it defines what a valid manifold mesh is so slicers stop guessing. Bambu Studio, PrusaSlicer and Cura all treat it as a first-class project format.
Commonly seen in: Bambu Studio, PrusaSlicer, Cura, Windows 3D Builder, Fusion 360. More on the 3MF 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 VTK 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 3MF 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.
VTK to 3MF: common questions
Is my VTK 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 VTK 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 3MF file look untextured?
Because this writer leaves them out. 3MF references an image by filename rather than storing it inside the file, so the images would have to travel separately and land where the file expects them, which is how a converted model arrives broken. Convert to GLB, FBX or USDZ instead if the textures need to stay with the model.
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 VTK:
Other ways to get to 3MF:
Or do something else with it: