3D & CADFreeNo uploadNo sign-up
STL Viewer
Preview a 3D-printing model in seconds: open the STL, spin it around, check its size and mesh, then send it to the slicer.
Drag to rotate · scroll to zoom · right-drag to pan
Opened in your browser. The file is never uploaded to a server.
How to use the STL Viewer
Drop the STL
Drag a binary or ASCII .stl file into the viewer. OBJ, 3MF, PLY and GLB models open too.
Look at it from every side
Rotate with the mouse or one finger, zoom with the wheel or a pinch, and pan with the right button or two fingers.
Check before printing
Read the size, triangle count and vertex count, turn on wireframe to see the mesh density, or save a PNG preview.
About the STL Viewer
STL is the standard file for 3D printing. Thingiverse, Printables, Cults3D and almost every CAD program export it, and every slicer, from Cura and PrusaSlicer to Bambu Studio, imports it. An STL is nothing more than a list of triangles that describe the surface of an object: no colours, no materials and no units.
That simplicity is why it helps to look at an STL before you print it. In this STL viewer you can see straight away whether a download is the part you expected, whether it is in one piece, which side should face the build plate and roughly how big it is. Because the file is opened on your own device, models you are designing for a client stay private.
Frequently asked questions
How do I open an STL file without installing software?
Drop it onto this page. The STL viewer runs in the browser on Windows, Mac, Linux, Android and iPhone, so you do not need Cura, Blender or any 3D app just to look at a model.
Does it support binary and ASCII STL?
Yes. Both variants open, including binary STL files that store per-face colours, which some programs export.
Is there a file size limit?
There is no fixed limit. Models of 100–200 MB open on a typical computer; very large scans may need more memory than a phone has.
Can the viewer repair or slice my model?
No, it is a viewer. It helps you check the shape and size before printing. Repairs and slicing are done in a slicer such as PrusaSlicer, Cura or Bambu Studio.
Are my STL files uploaded?
No. The file is read by your browser and drawn with WebGL on your graphics card. Nothing is sent to our server.