What happened to 3D Viewer
3D Viewer (first released as Mixed Reality Viewer in 2017) was the built-in Windows app for opening 3D files with a double-click. Microsoft has since moved it to its list of deprecated Windows features, and from July 2026 it can no longer be downloaded from the Microsoft Store. Installed copies keep working, but they are frozen: no updates, no fixes, and new PCs do not get it.
So on a fresh Windows 11 machine, double-clicking an .stl or .glb now asks
which app to use. Microsoft's own guidance points to the web-based Babylon.js
Sandbox, which is aimed mainly at glTF scenes.
The browser option: same files, nothing to install
Mes3D runs in Edge, Chrome or Firefox on any Windows PC. Drop a file on this page and it opens full screen.
| Format | 3D Viewer | Mes3D in the browser |
|---|---|---|
| STL (binary and ASCII) | Yes | Yes |
| 3MF | Yes | Yes, including Bambu Studio and OrcaSlicer projects |
| GLB / glTF | Yes | Yes (a .gltf with its .bin and textures from a folder or ZIP) |
| OBJ | Yes | Yes, with .mtl materials and textures |
| PLY | Yes | Yes |
| FBX | Yes | Yes |
| STEP / STP (CAD) | No | Yes, converted on your PC with OpenCASCADE |
| USDZ / USD | No | Yes |
| 3DM (Rhino) | No | Yes |
| DAE, 3DS, AMF, OFF, ABC | No | Yes |
| Animation playback, lighting effects | Yes | No |
| Works offline after first load | Yes | Yes |
| Install needed | Was built in | No |
3D Viewer had a mixed-reality mode and played FBX and glTF animations; Mes3D does not. What it adds is aimed at printing and CAD users: STEP files, point-to-point measurements in millimetres, and print checks such as volume, weight, watertightness and overhangs.
Make it feel like an app
You cannot make a website the default app for a file type, but you can get close:
- Edge: open this page, then ⋯ → Apps → Install this site as an app. Mes3D gets its own window, Start-menu entry and taskbar icon.
- Chrome: ⋮ → Cast, save and share → Install page as app (or More tools → Create shortcut… → Open as window on older versions).
- Drag files from File Explorer straight into that window.
Because everything runs locally, the window keeps working without an internet connection once it has loaded.
If you want an installed program
Being honest about the alternatives:
- Slicers — PrusaSlicer, OrcaSlicer, Bambu Studio and Cura all open STL,
3MF and OBJ, and can be set as the default app for
.stl. Best if you print. - Blender — opens nearly every format and lets you edit, but it is a large install and a heavy tool just to look at a file.
- F3D — a small, fast, open-source desktop viewer that can be the default app for many 3D formats.
Mes3D's niche is the case where you just want to see a file now, on any machine — a work PC without admin rights, a borrowed laptop — without installing anything or uploading the file.
What you can do once it is open
- Rotate, zoom and pan with the mouse; snap to front, top and side views.
- Switch between perspective and orthographic projection, or wireframe.
- Read the bounding-box width, height and depth in millimetres.
- Click two points to measure the distance between them.
- Open the analysis panel for volume, surface area, estimated print weight, watertightness and overhangs.
- Save a PNG snapshot of the current view.
On your phone
The same viewer works in a phone browser for viewing and dimensions. For measuring, analysis, cross-sections and AR on the phone itself, the Mes3D app is available for iPhone, iPad and Android.