If you've tried to open an STL, OBJ, or 3MF file on Windows recently and found that nothing happens — you're not alone. Microsoft has systematically removed every 3D viewing tool from Windows over the past two years, and the final removal is happening on July 1, 2026.
Here's the full story.
The timeline: death of 3D on Windows
In 2017, Microsoft launched the "Creators Update" with a big push into 3D content. They shipped three apps: Paint 3D for creating, 3D Builder for editing, and 3D Viewer for viewing. There was even a "Remix 3D" online community (shut down in 2020).
Nine years later, all three are gone:
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July 20243D Builder removed from Microsoft StoreThe STL editing and 3D printing prep tool disappeared without prior announcement. Users who relied on it for basic mesh viewing and repair were left without a replacement.
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August 2024Paint 3D deprecatedMicrosoft announced Paint 3D would be removed. It was widely used in schools for STEM education and by hobbyists for simple 3D creation.
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November 2024Paint 3D removed from Microsoft StoreThe app was pulled. Existing installs continue working but receive no updates and can't be reinstalled on new machines.
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February 20263D Viewer deprecatedMicrosoft officially deprecated the last remaining 3D tool. The deprecation notice links to "Babylon.js Sandbox" as the suggested alternative.
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July 1, 20263D Viewer removed from Microsoft StoreThe final cut-off. After this date, Windows has zero built-in 3D file viewing capability.
Why did Microsoft do this?
Microsoft hasn't given a detailed explanation. The deprecation pages simply list the apps under "features removed from Windows" alongside other Creators Update-era features. The most likely reasons:
- Low usage numbers. Most Windows users never touched the 3D apps. Microsoft prioritizes features that serve the broadest audience.
- Maintenance cost. Keeping desktop apps updated across Windows versions is expensive. Browser-based alternatives shift that cost to the user's browser.
- Strategic refocus. Microsoft's 3D efforts have shifted to enterprise (HoloLens, Azure Object Anchors, Dynamics 365 Guides). Consumer 3D viewing isn't a priority.
What does Microsoft suggest?
"For 3D content creation, we recommend Paint. For 3D viewing, we suggest Babylon.js Sandbox." — Microsoft Deprecation Resources page
The "Paint" suggestion is for 2D only — it has no 3D features. The "Babylon.js Sandbox" is a developer tool at sandbox.babylonjs.com. It can load 3D files, but it has no material presets, no AR, no sharing, no export — it's a debugging tool, not a viewer. For most users, this isn't a practical replacement.
Your alternatives
The good news: there are better options than anything Microsoft ever shipped. Here are the main categories:
GeometryViewer
Free, browser-based. STL, OBJ, GLTF, GLB, 3MF. AR, 24 materials, share links. No install.
3D Viewer (if still installed)
Works until you reinstall Windows. No updates. Will eventually break.
Babylon.js Sandbox
Microsoft's suggestion. Developer tool, no UI chrome, no materials.
MeshLab
Free, open source. Powerful but complex. Desktop install required.
3D Viewer.net
Browser-based. 18 formats. No AR, no materials, no sharing.
Blender
Free, open source. Overkill for viewing — it's a full 3D suite. 500MB install.
Why we built GeometryViewer
We saw this coming. When 3D Builder was removed in 2024, it was clear the other apps would follow. We built GeometryViewer to be the simplest possible way to view a 3D file — no install, no account, no upload to a server.
It runs entirely in your browser. Your files never leave your computer. And it does things the Windows apps never could:
- AR on your phone — tap "View in AR" and the model appears in your room at real-world scale
- 24 material presets — see your model in PLA with layer lines, chrome, wood, carbon fiber, jade
- Share with anyone — get a link, send it to a colleague, they see it in 3D instantly
- Embed on websites — two lines of code, works on Shopify, WordPress, anywhere
- Works everywhere — Windows, Mac, Linux, Chromebook, iPhone, Android
Try it right now
Drop any STL, OBJ, GLTF, GLB, or 3MF file onto the viewer. It opens in 3D instantly. On your phone, you can place it in AR.
Open GeometryViewerWhat about my existing 3D Viewer installs?
If you already have 3D Viewer installed on your PC, it will keep working — for now. But:
- It won't receive any updates or bug fixes
- If you reinstall Windows or get a new PC, you can't reinstall it from the Store
- Future Windows updates may break it (as happened with Paint 3D)
- It doesn't support 3MF, has no AR, and can't share models with a link
The writing is on the wall. It's worth switching now while it's not urgent, rather than scrambling when it finally breaks.
For 3D printing users specifically
If you used 3D Builder for STL viewing before printing, check out our 3D Print Preview page. GeometryViewer can simulate layer lines at different layer heights (0.12mm, 0.20mm, 0.35mm) so you can see what your print will actually look like. You can also check real-world size by placing the model in AR on your phone — no more printing at the wrong scale.
For educators and students
Paint 3D was popular in classrooms because it was free and pre-installed. GeometryViewer fills that gap: no install required (works on school Chromebooks), no accounts to manage, no IT department involvement. Students can view and interact with 3D models by just opening a browser tab.