Format guide

STL

Stereolithography

STL is the lingua franca of 3D printing, every slicer (PrusaSlicer, Bambu Studio, Cura, Simplify3D) reads it. Files are unstructured triangle soup: no scene graph, no materials, no scale info, just vertices and triangles. The format is ancient (1987) and primitive but its simplicity is exactly why it's universal. Two variants: ASCII (human-readable, big) and binary (compact, what most software produces).

How to open a STL file

Every 3D printing slicer, every CAD/3D tool (Blender, FreeCAD, Fusion 360, SolidWorks, Tinkercad). Free viewers: ViewSTL, MeshLab, online STL viewers.

Primary use

3D printing, feed an STL into your slicer to get G-code.

Convert other formats to STL

3MF → STL
OBJ → STL

Convert STL to other formats

STL → 3MF
STL → OBJ

Looking for something else? Browse the full list of 192 converters.