.STL File Extension
Stereolithography File
| Developer | 3D Systems |
| Popularity |
3.8 | 97 Votes |
What is an STL file?
An STL file is a 3D model saved in the Stereolithography (STL) file format developed by 3D Systems. It contains plain text or binary data that describes a set of triangular facets, which comprise a model. STL files are quite common, and they can be opened in many CAD and 3D modeling programs.
More Information
Stereolithography is a form of 3D printing primarily used for creating product prototypes. In the late 1980s, 3D Systems co-founder Chuck Hull patented stereolithography technology, and 3D Systems created the STL file format. Primarily, STL files contain 3D models meant to be printed using stereolithography.
Because the STL format was one of the first formats used to store models for 3D printing, a large number of 3D model viewers and CAD programs support it. STL files may be saved as plain text files, which contain human-readable triangular tessellation data, or as binary files, which contain the same data saved in a binary format. When opened in a text editor, plain text STL files appear as a list of facets and vertexes, complete with coordinates. These files always begin with the string solid ModelName.
NOTE: STL files are also sometimes referred to as Standard Triangle Language files and Standard Tessellation Language files.
How to open an STL file
You can open an STL file in many image viewers, 3D modeling, and CAD programs, including:
- Microsoft 3D Viewer (Windows)
- Apple Preview (Mac)
- MeshLab (multiplatform)
- Autodesk Fusion 360 (multiplatform)
You can also open plain text STL files in text editors, such as Microsoft Notepad and Apple TextEdit, to view the plain text data they contain. (If you open a binary STL file in a text editor, its data will appear as a series of unintelligible characters.)
How to convert an STL file
Several CAD and 3D model editing programs, including Autodesk Fusion 360 and Microsoft 3D Builder, can convert STL files to other 3D model formats. For example, Fusion 360 can export STL files to:
- .F3D - Fusion 360 Archive
- .3MF - 3D Manufacturing File
- .IPT - Inventor Part
- .FBX - Autodesk FBX Interchange File
- .OBJ - Wavefront 3D Object
- .SKP - SketchUp Document
- .SMT - Autodesk Shape Manager Text File
- .STP - STEP 3D Model
- .USDZ - Universal Scene Description Zipped
Apple Preview and Microsoft 3D Viewer can convert STL files to raster images. For example, Microsoft 3D Viewer can convert an STL file to the following formats:
- .PNG - Portable Network Graphic
- .JPEG -JPEG Image
- .BMP - Bitmap Image
- .TIFF - Tagged Image File Format
Apple Preview can also convert STL files to .PDF documents.