STL Viewers: Free and Open Source Programs to Download

3D printing

If you have a 3D printer or are seriously contemplating one, you have probably seen a few ways to get your data from design stage over to the printer itself. Some older machines (if you are buying used or using an older machine in a makerspace, for instance) have SD card access only – meaning you have to load your file to the SD card (from your computer) and then plug that card into the 3D printer itself. Most newer machines offer one or more ways, most often a USB direct cable from your PC.

It is important to have software that allows you to view STL files before you print them. However, CAD software can cost thousands of dollars making it an expensive purchase for the small business, consumer or prosumer (meaning you are contemplating a business but are still on the fence). If you want this ability to view and print without the traditional cost of software, this post is for you.

Free STL Viewers

  1. For a powerful viewer that also allows you to scale, cut, repair, and edit meshes, you can try netfabb Basic. The Basic version installs quickly and uses the same interface as the Professional version (with fewer features).
  2. ModuleWorks created STL View, which is a free, basic viewer available for multiple platforms. It supports both ASCII and binary formats of STL and lets you load more than one model at once.
  3. MiniMagics is a free STL viewer that works on older Windows versions (XP, Vista, 7). It has a tabbed, simple interface and allows you to attach comments to the file. The downside is that you must give them all your contact information before they will send you a link to download this viewer. However, there are English, German, and Japanese versions that you are free to share with others once you get their download.
  4. For an all-around general 3D CAD designed specifically for use with 3D printers, you can try Meshmixer. This program has limited files it can import or export (OBJ, PLY, STL, and AMF), but its 3D printing focus makes it stand out above the rest.
  5. SolidView/Lite is an STL Viewer that allows you to print, view, and rotate STL and SVD files. You can also measure SVD files with this software.

Open Source STL Viewers

  1. Assimp’s open3mod is a 3D model viewer that allows you to import and view many file formats (including STL). It exports STL, OBJ, DAE, and PLY files. The user interface is tabbed for easy inspection of the model.
  2. A good open source parametric modeling tool is FreeCAD. It allows you to import and export a variety of files including STL, DAE, OBJ, DXF, STEP, and SVG. Because it is a full-service CAD program, you can design from the ground up as well as adjust designs. It works on parameters, and you adjust designs by adjusting those.
  3. Wings 3D is a comprehensive CAD program available in many languages. You can import and export many file formats including STL, 3DS, OBJ, SVG, and NDO. Right-clicking in the program brings up a context-sensitive menu with descriptions that display when you hover over it. This interface requires a three-button mouse to use effectively.
  4. If you want STL viewing ability on the go, check out the very basic KiwiViewer for iOS and Android. It allows you to open and view a variety of file formats on your mobile device and manipulate the 3D image on the screen to get a more complete view of it. There aren’t any features that allow you to change the image, but it is a great way to look at ideas on the go.
  5. Meshlab is an STL viewer and editor created by students at the University of Pisa. It imports and exports a nice variety of file formats and allows you to clean, remesh, slice, measure, and paint models. It also comes with 3D scanning tools. Due to the ongoing nature of the project, it is constantly obtaining new features.
  6. For a bare-bones open source STL viewer, you could use Viewstl. This ASCII format STL viewer has very basic, easy-to-learn commands and works best with a three-button mouse.
  7. Someone asked if there are any “STL Viewers Online” meaning that they are completely online, no download. 3DViewer is your online option: it is not a download but a browser-based STL viewer. You need to create a free account to use this service, but once created, they offer you unlimited cloud storage and the ability to embed the images you view in your website or blog.
  8. If you are looking for a full-service modeling program, BRL-CAD contains many advanced modeling features. It has been in production for more than 20 years. It has its own interface and allows you to convert from one file format to another. This one is not for the basic user, though.
  9. To view STL, OFF, 3DXML, COLLADA, OBJ, and 3DS files, you can use GLC_Player. It offers an English or French interface for Linux, Windows (XP and Vista), or Mac OS X. You can also use this viewer to create albums and export these as HTML files.
  10. With a built-in post-processor and CAD engine, Gmsh is more than just a viewer. It balances somewhere between a full CAD program and a simple viewer.
  11. Pleasant3D was designed to work specifically on a Mac OS. It allows you to view both STL and GCode files, but it will not convert one to the other and it only offers basic editing abilities. It works nicely as a basic viewer without the clutter of many extras.