Open STL file online Free STL viewer
- No upload
- No account
- Size in mm and inches
- Up to 100 MB
Loading the viewer
How to
How to open an STL file
Four steps, all in the viewer above. Most files open in a few seconds; the only wait is your own computer reading the mesh.
- 01
Drop the STL file on the viewer
Drag the file onto the stage above, or press Open a file. OBJ, GLB, glTF, PLY, FBX and 3MF open too. No file at hand? Try the sample model opens one of our own 3D models.
- 02
Turn it and zoom in
Drag to orbit, scroll to zoom and right-drag to pan. Switch on Wireframe to see the triangles. If the model lies on its back, use the Z is up switch.
- 03
Check the size and the triangle count
The panel shows the size of the model in millimetres and inches, and its triangle and vertex count. If the size looks wrong, change File units: a 3D file stores numbers, not units.
- 04
Convert it if you need another format
Need GLB for the web or OBJ for an older program? Open the free 3D model converter and save the same file in another format.
What you see
A free STL viewer for print checks
- 01
Size in mm and inches. The width, depth and height of the model's bounding box, so you can see if it fits your printer bed before you slice it.
- 02
Triangle and vertex count. A quick check of how heavy the mesh is. Millions of triangles slow down slicers and web viewers.
- 03
Wireframe view. Shows the mesh itself, so you can see thin walls, dense areas and where a model was cut.
- 04
The right way up. STL and 3MF files usually treat Z as up. The viewer turns them upright, and you can switch that off.
From a photo
No STL yet? Make one from a photo
The studio can turn a photo of an object into a 3D model. Image to 3D gives you a textured GLB, which the 3D model converter saves as STL for your slicer. Open the result here first to check its size.
Generated models are a strong start, not a finished print. The side the camera never saw is a guess, and thin parts can come out soft. Check wall thickness in your slicer before you print.
Drop it on the viewer on this page. It opens in your browser in a few seconds, with no install, no account and no upload. It works in any current browser with WebGL, on Windows, Mac, Linux and most tablets.
Yes. There is no account, no watermark, no daily limit and no paid tier. The file is read by your own browser, so it costs us nothing to run.
No. The file is read in your browser and never leaves your device. We do not see it and cannot keep a copy.
A 3D file stores numbers without units. The viewer reads STL, OBJ, PLY and 3MF as millimetres, GLB and glTF as metres (the glTF standard) and FBX as centimetres. If your model was made in other units, change File units in the panel and the size updates.
OBJ, GLB, glTF, PLY, FBX and 3MF, up to 100 MB. A .gltf file that points to separate .bin or texture files may not open; use the .glb version instead. Files with Draco compression are not supported yet.
Yes, in two steps. Make a 3D model from the photo with Image to 3D in the studio (that part uses plan credits), then save it as STL with the free 3D model converter, or pick STL as the output format on the models that offer it.