The free replacement for Windows 3D Viewer
Microsoft removed 3D Viewer from the Microsoft Store on July 1, 2026. Open3D Viewer opens the same files — STL, GLB, OBJ, FBX, PLY, 3MF — plus CAD formats the old app never supported (STEP, IGES, DXF). Free. No account. No ads on Windows.
What happened to Microsoft 3D Viewer
Microsoft deprecated its Windows 3D Viewer app and pulled it from the Microsoft Store on July 1, 2026. If you double-click an .stl or .glb file on a fresh Windows 10 or Windows 11 install, you now see "no app associated with this file". Existing installs keep working — until you reinstall Windows or move to a new machine, at which point the app is gone.
Open3D Viewer is a direct drop-in: same "open the file, look at it" workflow, no sign-up, no Mixed Reality baggage, and it's actively maintained.
Open3D Viewer vs Microsoft 3D Viewer
| Capability | Microsoft 3D Viewer | Open3D Viewer |
|---|---|---|
| Opens STL, GLB, OBJ, FBX, PLY, 3MF | Yes | Yes |
| Opens STEP, IGES, DXF (CAD formats) | No | Yes |
| Walk-through mode | No | Yes |
| Measure two points in real units | Limited | Yes |
| Cross-section on any axis | No | Yes |
| HDRI environments | No | Yes |
| Screenshot + animated GIF capture | Screenshot only | Both |
| Runs in a web browser | No | Yes (open3d.app) |
| Available on Android and iOS | No | Yes |
| Requires a Microsoft account | No | No |
| Cost | Free (discontinued) | Free |
Every format the old app opened, plus more
Mesh formats. STL (ASCII and binary), GLB, GLTF, OBJ (with MTL sidecars), PLY, 3MF, FBX, DAE / Collada, 3DS.
CAD / engineering formats. STEP, STP, IGES, IGS, DXF. Microsoft 3D Viewer never opened any of these — Open3D Viewer does.
Point clouds. PLY files from photogrammetry, LiDAR scans, and Gaussian-splat exports render as point clouds instead of failing.
How to make Open3D your default STL / GLB opener
- Install Open3D Viewer from the Microsoft Store.
- Right-click any .stl or .glb file in File Explorer.
- Choose Open with → Choose another app.
- Select Open3D Viewer, tick Always use this app to open .stl files, and click OK.
Windows sets one default per extension, so repeat once per file type you commonly open.
What Open3D Viewer adds on top
- Walk-through mode — step inside architectural GLBs and STLs. Virtual joystick on mobile, WASD + mouse on desktop.
- Point-to-point measurement in mm, cm, m, or inches.
- Cross-section — drag a clipping plane through any axis to inspect interiors and wall thickness.
- HDRI environments — Studio, Sunset, Sky lighting presets, plus arbitrary background colours (independent of the HDRI).
- Persistent settings — model colour and background stick across every file and across app restarts.
- Print-readiness sniff test for STL / OBJ / 3MF — manifold check, overhang count, bed fit against Bambu A1, Prusa MK4, Ender 3.
Try it in a browser first
Not ready to install? The web viewer at open3d.app/viewer opens the same file formats in a browser tab. Drag a file in and it renders locally — nothing uploads to a server.
FAQ
Why did Microsoft remove Windows 3D Viewer?
Microsoft removed 3D Viewer from the Microsoft Store on July 1, 2026, along with a group of legacy Windows Mixed Reality apps. Microsoft has not published a replacement. Existing installs continue working, but new users on Windows 10 or Windows 11 can no longer download it.
Does Open3D Viewer open every format Windows 3D Viewer opened?
Yes — STL, GLB, OBJ, FBX, PLY, and 3MF all work. Open3D Viewer additionally supports STEP, IGES, and DXF, which Microsoft 3D Viewer never handled.
Is Open3D Viewer really free?
Yes. The Windows app has no ads, no in-app purchases, no subscription, and no Microsoft account requirement. The mobile apps carry a single banner ad; the web viewer at open3d.app is completely free.
Does it work offline?
Yes. Once installed from the Microsoft Store, Open3D Viewer opens and renders files fully offline. There are no network calls to load a model.
Can I open STEP or IGES CAD files?
Yes. Open3D Viewer opens .step, .stp, .iges and .igs files directly, no Fusion 360, SolidWorks, or AutoCAD required. This is the biggest capability gap versus the discontinued Microsoft 3D Viewer.
Does it need a Microsoft account?
No. You need to be signed into the Microsoft Store to install any app (that's a Store requirement), but Open3D Viewer itself has no account of its own and never asks you to sign in.
Is my file uploaded anywhere?
No. Both the Windows app and the web viewer render your file entirely on your device. Nothing crosses the network. You can verify this in your browser's network tab or Windows' network activity monitor.