Open STL file

The most common choise: Stereolithography CAD data

How to open Stereolithography CAD data .stl files

stl file icon Have you had trouble opening the stl file on your computer? What are stl files? We explain what they are and recommend software that we know will open them.

What is stl file?

Files with stl extension can be mainly found as stereolithography files for 3D printers. Used in many CAD programs as output format for models and prototypes that could be printed in stereolithography devices.

Stereolithography CAD data description

The stl file extension is mainly  associated with Standard Tessellation Language, a common CAD stereolithography format for 3D modeling, prototyping and for use in 3D printers.

The STL format was developed by the Albert Consulting Group (Albert-Battaglin Consulting Group today) for 3D Systems in 1987 for moving 3D CAD models to its stereolithography apparatus (SLA) machines. 

The stl file describe only the surface geometry of a 3D object without any representation of color, texture or other common CAD model attributes. It exists in both binary and ASCII format and probably many variants were created through the years.

Historically, the use of this format is tightly tied with stereolithography - 3D printing in series slices.

It is easy to output, so most CAD programs that deal with 3D models can export to STL.

Note that STL is one of the world's worst 3D file formats. Many people continue to believe it is a high quality CAD file format when that has little reality. It should never be used to convert data from one 3D program to another, and especially not from any CAD program. If you are sent a STL file then the data vendor should be asked for the original, native CAD file, IGES or STEP file instead.

A .stl file only contains a run of individual triangles with only vertex information and nothing else. There is no accurate vertex normals smoothing information, no uv texture coordinates or vertex colors, no materials, no hierarchy, no lights, no cameras, etc. It doesn't get much worse.

Note: In Windows, the STL extension is by default associated with Certificate Trust List. This is not in any way related to stereolithography.

MIME type:

Suggested software to open stl file


A family of 2D/3D CAD software products for Windows

TurboCAD for Mac

A 2D/3D CAD software for OS X

There are other STL filename extensions with the same .stl suffix

stl - Adobe Fireworks style library

An stl file extension is related to the Adobe Fireworks, a picture editing software and used for its style libraries.

stl - C++ standard template library

An stl file extension is related to the Microsoft Visual C++ IDE for C/C++ programming language. An stl file stores C++ standard template library.

stl - ClarisWorks data

An stl file extension is related to the ClarisWorks office suite and used for its data files.

stl - EBU-standard open and teletext

Files with stl file extension might also be found as part of SoftNI software solutions. EBU-standard related file.

stl - Micrografx Designer stylesheet

An stl file extension is related to the Micrografx Designer and iGrafx Designer. An stl file is used to store stylesheet.

stl - ROSE Online game data

Files with stl file extension can also be found as game resource data packs for ROSE Online MMORPG computer game.

stl - SPEFO stellar spectra analysis

An stl file extension is associated with the SPEFO and used for its stellar spectra analysis files.

stl - Win2020 screen subtitle

Files with stl file extension can also be possibly found as old subtitles saved in Win2020 format.

What file extension actually is?

Simply put, file extensions are the characters after the dot in the computer file name, so for example document-name.pdf has file extension „pdf“. This helps Windows to identify which program should be used to open the file.

We can help you to open your file

Our database contains a huge list of different file extensions, usually with detailed description and programs that can be used to open or otherwise work with that particular file type.

Only original software

Every software listed in our database is verified and ve provide link to the developer or to the software own website, which should hopefuly be enough for you to download the most recent version of the program.