Visualization Toolkit .vtk
Scientific visualisation meshes from ParaView and VTK.
What a .vtk file holds
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.
| Data | Stored in VTK |
|---|---|
| Geometry | Yes |
| Materials and colour | No |
| Texture maps | No |
| Animation and rigs | No |
| Scene hierarchy | No |
| Read here | Yes |
| Written here | No |
Tested against a real file
The last sweep loaded bunny.vtk from three.js examples with its 2 sidecar files through the viewer on this site: 69,451 triangles across 1 meshes and 1 materials, in 2.2 seconds. Every format's result is on the test results page, run 2026-09-08.
Convert VTK to another format
Every pairing has a page saying what survives the trip.
Other things to do with a .vtk file
Questions about VTK
How do I open a .vtk file?
Drop it into the viewer on this site and it opens in the browser, with the scene tree, the materials and the mesh statistics. Nothing is uploaded. If you want it in another program instead, convert it to GLB, which almost everything reads.
Is VTK a good format to archive in?
VTK stores geometry. Anything outside that list will not be in the file at all, so archive the original alongside it if the surfacing or the rig matters.
Does converting VTK lose quality?
Geometry is copied vertex for vertex, so the shape does not degrade. What gets lost is whatever the target format has no field for: convert to STL and the materials go, convert to OBJ and the animation goes. The comparison table on each converter page says exactly which.
Formats that hold the same things
Or go back to the full format reference.