A .STL file is a Stereolithography 3D Mesh associated with CAD & 3D. Raw 3D surface mesh format composed of triangular facets used universally in 3D printing.

How do I open a .STL file on Windows or Mac?

You can open .STL files using PrusaSlicer, Cura Slicer, Blender 3D Suite, Windows 3D Builder. If you do not have native software installed, you can use OpenAnyFile's free File Identifier or convert .STL to a standard format in your browser.

Is a .STL file safe to open?

This format carries a safety rating of Low Risk. Pure geometric vertex mesh data. Completely safe.

Can I convert a .STL file to other formats?

Yes! .STL can be converted to formats such as .OBJ, .3MF directly in your web browser.

What should I do if a .STL file is corrupted or won't open?

If your .STL file displays an invalid header or signature error, check its magic bytes hex header (73 6F 6C 69 64 (ASCII: solid) or 80-byte header (Binary)) using OpenAnyFile's Magic Byte Detector or follow our step-by-step file repair guide.

CAD & 3D • MIME: model/stl

.STL – Stereolithography 3D Mesh

Raw 3D surface mesh format composed of triangular facets used universally in 3D printing.

Primary Category CAD & 3D

MIME Type model/stl

Magic Bytes Signature 73 6F 6C 69 64 (ASCII: solid) or 80-byte header (Binary)

Security Risk Rating Low Risk

Recommended Software to Open .STL

PrusaSlicer

windows, mac, linux • Free

Cura Slicer

windows, mac, linux • Free

Blender 3D Suite

windows, mac, linux • Free

Windows 3D Builder

windows • Free