Free Online STL Viewer
Open your STL file right on this page: rotate and zoom it, measure distances and angles, cut a section and see its size, volume and holes.
- Free
- No sign-up
- No install
Open Files → rotate and zoom → Measure or Section
What you can do with your STL file
Rotate, zoom and pan
Turn the model with the mouse or touchpad and zoom in on any detail. Front, Top and Isometric views are one click away.
Measure distances and angles
Measure Distance shows the distance between points you pick on the model, and Measure Angle the angle between edges.
Cut a section
Section cuts the model with a plane, so you can look inside it and check walls and cavities.
Check size and volume
Bounding Box draws the overall size. The Information panel shows the dimensions, volume, area, triangle count and holes.
Convert the file
Save your STL file in another format on the converter pages below or in the free desktop app.
How to open an STL file in 3 steps
Open your STL file
Click Open Files in the viewer above, then Browse… and pick your .stl file. It opens in your browser, with no account and no install.
Rotate and zoom
Drag to turn the model and scroll to zoom. The View Settings tab has Front, Top and Isometric views, and Fit Data brings the model back into view.
Measure or cut a section
Click Measure Distance, Measure Angle or Section on the Viewer tab. To save the model in another format, use a converter below or the desktop app.
STL viewer FAQ
How do I open an STL file online?
Click Open Files in the viewer at the top of this page, then Browse… and pick your .stl file. MeshInspector opens binary and ASCII STL files right in your browser, with no account and no install. The file is read in the memory of your browser and is not uploaded to a server.
Is this STL viewer free?
Yes. Viewing STL files on this page is free and needs no sign-up: open the model, rotate it, measure distances and angles, and cut sections. The desktop MeshInspector app is free on the Community plan too; some advanced tools, such as Mesh Healer, need a paid plan.
Can I measure an STL model in the browser?
Yes. Measure Distance shows the distance between points you pick on the model, and Measure Angle the angle between edges. Bounding Box draws the overall size, and the Information panel lists the dimensions, volume, surface area and triangle count. Section cuts the model with a plane so you can look inside.
Why does my STL file not open?
Check that the file is complete: an interrupted download or an empty export will not open. Very large models are limited by the memory of your browser, so open those in the desktop app. If the model opens but has holes or flipped triangles, check and fix it with our free STL File Repair tool.
How do I convert an STL file to another format?
Use the STL converters linked below. STL to OBJ, 3MF and PLY run in your browser without sign-up: open the file, click Export and choose the format. STL to glTF needs the free desktop app, which writes glTF with Save Scene As.
Add an STL Viewer to Your App
- Multi-Format Support — meshes, point clouds, voxels, and line data
Modern UI — built with Dear ImGui: ribbon interface, scene tree, view cube, and measurement tools.
Order-Independent Transparency (OIT) — realistic rendering of transparent materials.
Customizable Interaction — support for mouse, keyboard, touch gestures, and SpaceMouse devices.
Plugin Architecture — extend the Viewer with your own tools and workflows.
