STL (.stl)


    • MIME type: application/sla
    • STL computer-aided design and manufacturing format.
    • 3D geometry format.
    • Commonly used for representing solid models in rapid prototyping systems.
    • Native format of the 3D Systems stereolithography CAD software.
    • Developed in 1989 by 3D Systems, Inc.
    • STL is an acronym derived from stereolithography.
    • ASCII or binary format.
    • Stores a 3D object, including solid, as a surface formed by a collection of adjacent triangles.

Import & Export

  • Import["file.stl"] imports an STL file as a MeshRegion object representing the surface.
  • Import["file.stl",elem] imports the specified element from an STL file.
  • The import format can be specified with Import["file","STL"] or Import["file",{"STL",elem,}].
  • Export["file.stl",expr] exports a 3D mesh-based geometric region to a binary STL file. The expr can be any region that is ConstantRegionQ or a Graphics or Graphics3D object.
  • The export format can be specified with Export["file",expr,"STL"] or Export["file",expr,{"STL",opt1->val1,}].
  • See the reference pages for full general information on Import and Export.
  • ImportString and ExportString support the STL format.

Import Elements

  • General Import elements:
  • "Elements"list of elements available in this file
    "Rules"list of rules for each element
    "Options"list of options and settings
    "Summary"summary of properties
    "CoordinateTransform"transformation function from STL format
  • Data format representation elements:
  • "BinaryFormat"whether the file is a binary or ASCII STL
    "VertexData"list of vertex coordinates
    "PolygonData"list of polygon elements in indexed form
    "PolygonCount"number of polygons
  • Geometry representation elements:
  • "BoundaryMeshRegion"boundary mesh representation of a solid
    "MeshRegion"mesh representation of a surface
  • Graphics representation elements:
  • "Graphics3D"STL file represented as a Graphics3D object
    "GraphicsComplex"STL file as a GraphicsComplex object
    "PolygonObjects"list of polygon primitives in absolute coordinates
  • Import and Export use the "MeshRegion" element by default for STL files.


  • Export options:
  • "BinaryFormat"Truewhether to write a binary or ASCII file


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Basic Examples  (2)

Import a 3D model from STL as a MeshRegion object:

Click for copyable input

Summary properties of the solid model:

Click for copyable input

Export a 3D model to an ASCII STL file:

Click for copyable input

Print the raw textual contents of the file:

Click for copyable input

Scope  (13)

Import Elements  (12)

Export Options  (2)

Introduced in 2000
Updated in 2015