Open and view STL files online — free, no signup, no upload
An STL file (STereoLithography) stores a 3D model's surface as a mesh of triangles. It's the standard format for 3D printing and CAD exchange. This viewer opens STL files right in your browser so you can rotate, zoom and pan a model and check its bounding-box dimensions and triangle count — without installing software or sending your file anywhere.
How to view an STL file
1. Drag your file onto the box above, or click Open STL file. 2. Drag to orbit, scroll to zoom, right-drag to pan. 3. Read the width/depth/height and triangle count in the panel.
Frequently asked questions
How do I open an STL file online?
Drag your .stl onto this page or click Open File. It renders instantly in your browser — rotate, zoom and pan. Nothing is uploaded; the file is read and displayed entirely on your device.
Is it safe to view my STL here?
Yes — the viewer is 100% client-side. Your STL never leaves your computer and is never sent to a server, so there is no upload and nothing is stored.
Does it support binary and ASCII STL?
Yes. The format is detected automatically, so you can open either kind without converting first.
What do the dimensions mean?
The panel shows the bounding-box size (width, depth, height) in the file's own units — usually millimetres — plus the triangle count, so you can check a model's real size before printing.