At One Place

.stl files

.stl file
Stereolithography Model
The universal 3D printing format — a shell of triangles with no colour or units.

What opens a .stl file

Windows
Ultimaker Cura, PrusaSlicer, Bambu Studio, Blender, MeshLab
macOS
Ultimaker Cura, PrusaSlicer, Bambu Studio, Blender, MeshLab
Linux
Ultimaker Cura, PrusaSlicer, Blender, FreeCAD
In a browser
Autodesk Viewer

What a .stl file is

STL came out of 3D Systems in 1987 and describes an object as a mesh of triangles. It carries no colour, materials or scale information, which is the classic cause of a model printing at the wrong size. Slicers such as Cura, PrusaSlicer and Bambu Studio open one and turn it into printer instructions; nothing on Windows or macOS previews an STL out of the box, so you install one of those or Blender to look at it.

Converting it

A .stl file is commonly converted to .obj, .3mf, .gcode, .step or .fbx. It is a binary format, so a text editor will show unreadable characters rather than its contents.

Details

Extension
.stl
Full name
Stereolithography Model
Category
3D and CAD
MIME type
model/stl
Created by
3D Systems
Format
Binary

Common questions

How do I open a .stl file?
On Windows use Ultimaker Cura; on macOS use Ultimaker Cura; on Linux use Ultimaker Cura. The universal 3D printing format — a shell of triangles with no colour or units.
What is a .stl file?
Stereolithography Model. STL came out of 3D Systems in 1987 and describes an object as a mesh of triangles. It carries no colour, materials or scale information, which is the classic cause of a model printing at the wrong size.
Can I convert a .stl file?
Yes. It is usually converted to .obj, .3mf, .gcode, .step or .fbx, either by exporting from one of the programs listed above or with a format converter.

Related pages

Sources

  1. Media Types Registry — IANA
  2. Official vendor product documentation — At One Place

How these figures are compiled and checked