Each one is right for something and wrong for something else, and both are stated at the top of its entry. That includes Heimdall3D, which is last on the list. The tables under the list are built from each product's own documentation.
For Sharing.
Wrong for A file that must stay private, or a folder of them.
A model uploaded once opens for anyone with the link, in any browser, with its animation playing. The editor sets materials, lights and post-processing. The free plan allows 10 uploads a month at 100 MB each, all of them public, and each file in a folder is a separate upload. Pro is $15 a month billed yearly.
For One file, once, on any machine.
Wrong for Anything animated. Playback has been an open request since November 2021.
It opens in a browser tab and reads STEP, IGES, IFC and 3DM among others. Heimdall3D reads none of those four. It exports to glTF, OBJ, STL, PLY, OFF, 3DM and BIM. Free and open source under MIT.
For A Windows 10 machine that already has it.
Wrong for A fresh Windows 11 machine. It left the Store on 1 July 2026.
It opens 3MF, FBX, GLB, glTF, OBJ, PLY and STL in its own window, free. Microsoft deprecated it in February 2026. Installed copies keep working.
For JPEG, PNG and TIFF.
Wrong for Any 3D file on Windows 11.
Windows 11 draws thumbnails for those three. A 3D file gets a generic icon and nothing in the preview pane. Windows 10 previewed GLB, OBJ and FBX through the Mixed Reality Viewer component. Windows 11 does not ship that component.
For The images it already reads.
Wrong for 3D files on a machine without the Windows component. A fresh Windows 11 machine is one.
Its viewer opens JPEG, PNG, TIFF, WebP and, since version 13, DDS. Since Opus 12.10 the viewer pane also shows 3MF, FBX, GLB, glTF, OBJ, PLY and STL through the Windows Mixed Reality Viewer component. The 3D object preview plugin on the Resource Centre is that feature. It ships inside Opus and there is nothing to download. Since 1 July 2026 the Store no longer supplies the component.
For Changing the file.
Wrong for Looking through a folder. Each file opens in turn, in its own window.
It imports OBJ, FBX, glTF, Collada, PLY, STL, BVH, Alembic and USD, edits all of it, plays and edits animation, and exports to each of those. Its image editor opens EXR, Radiance HDR, TIFF, TGA, PNG, JPEG and WebP. Free under the GPL, on Windows, macOS and Linux.
For Thumbnails on Windows and Linux, and STEP, USD, point clouds and splats.
Wrong for The preview pane in Explorer or Directory Opus, thumbnails on a Mac, and any change to the file.
It draws 3D thumbnails in Windows Explorer through a shell extension that its installer registers, and on Linux in nautilus, thunar, pcmanfm and caja through the XDG thumbnailer. macOS gets the viewer window. That window takes its instructions from the command line, configuration files, hotkeys and drag and drop. Its documentation states there is no plan for menus and buttons. It plays animation. It reads STEP, IGES, IFC, USD, Alembic, DXF, point clouds and Gaussian splats. Heimdall3D reads none of those. Free under the BSD licence, on Windows, macOS and Linux.
For A folder of files on Windows.
Wrong for A Mac, Linux, a phone or a browser, STEP, IFC, USD or a point cloud, and any change to the file.
Every 3D file and HDR image in the folder draws its own thumbnail. The selected one opens in the preview pane of Explorer or Directory Opus, where it orbits and its animation plays. The extensions are in the table below. The renderer is a separate process, so a rendering crash cannot take the host down. Windows 10 and 11 only. Thumbnails, the pane and the viewer window are free. Saving a picture out of the viewer costs €49 once.
| Extension | Heimdall3D | Windows Explorer | Directory Opus 13 | Microsoft 3D Viewer | Online 3D Viewer | Sketchfab | Blender 4.5 | F3D |
|---|---|---|---|---|---|---|---|---|
| Models and motion capture | ||||||||
.3ds | ✓ | ✓ | ○ | ○ | ✓ | |||
.3mf | ✓ | ✓1 | ✓ | ✓ | ○ | ○ | ✓ | |
.bvh | ✓ | ○ | ✓ | |||||
.dae | ✓ | ✓ | ○ | ✓ | ✓ | |||
.fbx | ✓ | ✓1 | ✓ | ✓ | ✓ | ✓ | ✓ | |
.glb | ✓ | ✓1 | ✓ | ✓ | ✓ | ✓ | ✓ | |
.gltf | ✓ | ✓1 | ✓ | ✓ | ✓ | ✓ | ✓ | |
.obj | ✓ | ✓1 | ✓ | ✓ | ✓ | ✓ | ✓ | |
.mtl | ✓ | ○ | ○ | ○ | ✓ | ✓ | ||
.ply | ✓ | ✓1 | ✓ | ✓ | ✓ | ✓ | ✓ | |
.stl | ✓ | ✓1 | ✓ | ✓ | ✓ | ✓ | ✓ | |
.vrm | ✓ | ○ | ○ | ○ | ||||
| HDR images | ||||||||
.exr | ✓ | ○ | ○ | ✓ | ✓ | |||
.hdr | ✓ | ○ | ○ | ✓ | ✓ | |||
.pfm | ✓ | ○ | ○ | ○ | ||||
.pic | ✓ | ○ | ○ | ○ | ||||
| Textures and images | ||||||||
.basis | ✓ | ○ | ○ | ○ | ||||
.dds | ✓ | ○ | ✓ | ○ | ||||
.jpg | ✓ | ✓ | ✓ | ✓ | ✓ | |||
.ktx2 | ✓ | ○ | ○ | ○ | ||||
.png | ✓ | ✓ | ✓ | ✓ | ✓ | |||
.tga | ✓ | ○ | ○ | ✓ | ✓ | |||
.tif | ✓ | ✓ | ✓ | ✓ | ✓ | |||
.tiff | ✓ | ✓ | ✓ | ✓ | ✓ | |||
.webp | ✓ | ○ | ✓ | ✓ | ✓ | |||
✓ the product's own documentation lists the extension. An empty cell means the documentation does not list it. ○ not checked. 1 through the Windows Mixed Reality Viewer component, which Windows 11 does not preinstall and which left the Microsoft Store on 1 July 2026.
| Heimdall3D | Windows Explorer | Directory Opus 13 | Microsoft 3D Viewer | Online 3D Viewer | Sketchfab | Blender 4.5 | F3D | |
|---|---|---|---|---|---|---|---|---|
| Runs | Inside Windows Explorer and Directory Opus 13, on Windows 10 and 11 | Windows | Windows | Its own window on Windows. Preinstalled on some Windows 10 machines, on no Windows 11 machine, and withdrawn from the Store on 1 July 2026 | A browser tab | A browser tab, after upload | Its own window on Windows, macOS and Linux | Its own window on Windows, macOS and Linux |
| Thumbnails in the file list | Every supported file, rendered from the file and cached | JPEG, PNG and TIFF | Images. 3D files not checked | Not checked | There is no file list | There is no file list | There is no file list | Windows through a shell extension its installer registers, and Linux through the XDG thumbnailer in nautilus, thunar, pcmanfm and caja. None on macOS |
| Preview pane | Explorer and Opus. The model orbits and its animation plays | None for 3D files on Windows 11 | 3D through the Windows component when it is present1 | Its own window | The tab | The tab | Its own window | |
| Animation | Plays, with skinning. A skeleton-only BVH is retargeted onto a rigged mannequin | Not checked. An Opus developer reported in April 2019 that the Windows component stopped playing animation after a Windows update | Plays the animations in the file, per Wikipedia. The same April 2019 report applies | An open request since November 2021 | Plays skeletal, solid and morph target animation | Plays and edits | Plays | |
| HDR images | Decoded in floating point. Exposure in EV stops, tone mapping, gamma, channel isolation, the RGBA value under the pointer | Not checked | Not checked | EXR and Radiance HDR open in the image editor | Opens .hdr and .exr | |||
| Edits the model | Not checked | Materials, lights and post-processing in its editor | Everything | |||||
| Converts | Not checked | Exports 3DM, BIM, glTF, OBJ, OFF, STL and PLY | Not checked | Exports every format it imports | ||||
| The file leaves your machine | Never. Everything runs locally | Never | Never | Never | Not checked | Yes. It is uploaded to Sketchfab, and on the free plan every upload is public | Never | Never |
| Price | Thumbnails, the pane and the viewer are free. €49 once for saving an image, copying a frame, a sprite sheet and a recorded turntable | Part of Windows | Included with Directory Opus | Free | Free, MIT licence | Free plan: 10 uploads a month, 100 MB per file, all public. Pro is $15 a month billed yearly | Free, GPL | Free under the BSD licence |
Heimdall3D runs on Windows 10 and 11 only. It lives inside Windows Explorer and Directory Opus 13 and never opens in a browser tab, so a model on a Mac, on Linux or on a phone needs one of the others.
It reads the file and changes nothing in it. Editing and conversion need Blender or Online 3D Viewer. STEP, IGES, IFC, USD, Alembic and point clouds are outside its list, and F3D reads all of them and thumbnails them on Windows.
Thumbnails, the preview pane and the viewer window are free and do not expire. Saving an image, copying a frame, rendering a sprite sheet and recording a turntable cost €49 once. Blender does all four for nothing.
Thumbnails, the preview pane and the viewer window are free, need no account and do not expire. The installer asks which of Windows Explorer and Directory Opus 13 to install into.
Sketchfab, Blender, Online 3D Viewer, 3D Viewer and F3D are the products of their own makers.