Is it a replacement for Microsoft 3D Viewer?

Yes. Microsoft removed 3D Viewer from the Store in July 2026. Open3D Viewer supports the same formats plus STEP, IGES, DXF and DWG.

Does it cost anything on Windows?

No. The Windows build is fully free, no ads, no subscriptions, no Microsoft account required.

Windows 10 · Windows 11

STL viewer for Windows.

Free from the Microsoft Store. Registers as the default .stl handler so double-click just works again — the way it used to before Microsoft retired 3D Viewer in July 2026. Also opens STEP, IGES, DXF, DWG, GLB, OBJ, FBX, 3MF and eight more formats.

Get on Microsoft Store → The full replacement story

What you can do with it

Double-click any .stl in File Explorer, Outlook, or a browser download — opens instantly
Orbit with the right mouse button, pan with middle, zoom with scroll
Measure point-to-point in mm, cm, m, or inches — the print size before you slice
Cross-section any axis with a draggable plane
Solid, wireframe, X-ray, matte modes — press W, X, or S to switch
Screenshot to PNG or record a 360° orbit GIF for a build log
Print-readiness check: manifold, normals, wall thickness before the slicer
In v1.2, connect Claude or ChatGPT via MCP and ask the AI to fill holes or preview materials on the file

The Microsoft 3D Viewer story

Microsoft removed 3D Viewer from the Store in July 2026. That broke a workflow a lot of Windows users had settled into: double-click an STL from your slicer, from a Bambu download, from a Thingiverse export, and see it in a viewer within seconds.

Open3D Viewer re-enables that. Install it from the Microsoft Store; it registers file associations for .stl, .glb, .obj, .fbx, .3mf, .step, .iges, .dxf, and .dwg. From that point on, File Explorer opens 3D files with Open3D by default, and every double-click behaves the way it used to.

Privacy: no upload, no account, no ads

The Windows build has no ads, no telemetry beyond a crash report you can opt out of, and no account requirement. Files are parsed on-device by native code; nothing crosses the network.

FAQ

How do I open an STL file on Windows now that 3D Viewer is gone?

Install Open3D Viewer from the Microsoft Store, then right-click any .stl → Open with → Choose another app → Open3D Viewer → check Always use this app. Double-click works from then on.

Is Open3D Viewer a real replacement for Microsoft 3D Viewer?

Yes. Same formats plus more (STEP, IGES, DXF, DWG on Windows). Same double-click file-association workflow. Free, ad-free on Windows, no Microsoft account required.

Can I open a large STL from a photogrammetry scan?

Yes. The Windows build handles STL files up to 2 GB. Real usable ceilings are around 50 million triangles on a modern desktop.

Does it work offline?

Yes. Fully offline after install. Optional Crashlytics ping if the app crashes; that can be disabled in Settings.

What about ASCII vs binary STL?

Both are auto-detected and load the same way. Binary is far more common. If you need to inspect ASCII structure, open the file in Notepad or VS Code alongside.