STL Viewer

Drop an .stl and look at it in 3D straight away — binary or ASCII, one file or several. The size in millimetres and the triangle count are shown under the view.

How to open an STL file online

Drop one or more .stl files above, or click Choose file.
Drag to rotate, scroll to zoom, right-drag to pan. Click an object in the list to focus it.
The bar under the view shows the selection's size (X × Y × Z) in millimetres and its triangle count.

More than a viewer

Several STLs at once, each listed separately — tick them on and off.
Convert to 3MF, OBJ, GLB or STEP with the export panel.
Files open locally, so even large models load without waiting for an upload.

Frequently asked questions

Which STL files does it open?

Binary and ASCII STL, including binary files whose header starts with "solid" and files with a Materialise colour in the header.

Can I open STL files on a phone?

Yes, in any current mobile browser with WebGL.

Is my file uploaded?

No. It is read and displayed in your browser only.