STL is one of the most popular 3d file formats in the 3d printing industry because it is very light and easy to edit.
The STL file is much lighter in size than other 3d file formats because it does not contain data about colors, materials, and textures but only the surface geometry data of the object.
By default, you will not be able to view the designs inside the STL file. You need to use the STL viewer software. STL viewer software will help you preview the model’s design before using them for more specific tasks in slicer software or editing the model in CAD software.
This article will summarize the best STL viewer software available today, classified by software type (offline or cloud), operating system (Windows or Mac, Android or IOS).
To save you time, the table below is a quick summary of the top 23 best free STL viewers, including software type (standalone or cloud) and compatible operating systems and our rating.
Best free offline (standalone) STL viewer software for Windows OS | ||||
Name | File type | Special features | Rating | Download |
Papa’s Best STL Viewer  | FBX, STL, OBJ, glTF, GLB, PLY, 3MF | Enable thumbnail for STL | 9.5 | |
Materialise MiniMagics | Free STL File Viewer  | .stl, .magics, .mgx, and .3mf | Verify Part Printability | 9 | |
3D-Tool Free Viewer  | 3ds, 3mf, asc, dwg (2D), dxf (2D), obj, iv, ply, slp, stl, wrl, xgl, zgl | 3D-NativeCAD Converter | 8.5 | |
EasyViewStl  | stl | Support up to 10,000,000 triangles mesh. | 8 | |
STLView - A Free STL Viewer  | stl | Super lightweight, touchscreen support on android. | 7.5 | |
Paint 3d  | .fbx, .3mf, .stl, and .obj | 3d modeling | 7 | |
Gmsh  | .stl .obj | Super lightweight | 6.5 | |
ADA 3D  | .stl .obj | Super lightweight | 6 | |
Best free offline (standalone) STL viewer software for MAC | ||||
Pleasant3D v2.6  | .stl .obj | Super lightweight | 8 | |
Mac OS X Preview  | .stl | built-in STL file viewer for MAC OS. | 7.5 | OS built-in app |
Matt Keeter // fstl  | .stl | Super lightweight, work on multiple OS. | 7 | |
Best free online (cloud) STL viewer software | ||||
Autodesk Viewer  | Over 80 file types including STL, STEP, OBJ, RVT, and Solidworks. | stl file store on Autodesk cloud storage for 30 days for free. | 9.5 | |
ViewSTL  | STL, OBJ, 3MF, VF, VSB, VSJ | Send model to 3d printing service. | 9 | |
Tinkercad  | .stl .obj .svg | an online 3D modeling program that runs in a web browser. | 8.5 | |
3DViewer.net  | obj, 3ds, stl, ply, gltf, glb, off, bim, 3dm, fbx, dae, wrl, 3mf, stp, ifc | Open source | 8 | |
Sharecad  | STEP, STP, IGES, IGS, BREP, STL, SAT (ACIS), Parasolid® (X_T, X_B), SolidWorks® (SLDPRT), IPT, IFC, OBJ | free iframe API | 7.5 | |
Modelexchange  | stl | auto rotation | 7 | |
Best Android STL viewer app | ||||
CAD Assistant  | STEP, IFC, IGES, BREP, glTF, JT, PLY, STL, OBJ, 3DM | 3d file converter | 8 | |
Fast STL Viewer  | stl | auto rotation | 7.5 | |
exocad webview – Fast STL 3D Viewer  | STL, OBJ, PLY | Change model transparency | 7 | |
Best IOS STL viewer app | ||||
STL Simple Viewer  | stl | Load stl file from zip file | 8 | |
Emb3D 3D Model Viewer  | 3DS ASE DAE FBX GLB GLTF OBJ PLY STL ZIP | Enhanced Visualization | 7.5 | |
STL Master  | STL, OBJ | Custom background & Screen recording | 7 | |
If you want to learn more about each software, scroll down and read our detailed review.
Contents
What is STL file format
If you are involved with 3d printing, you will be very familiar with the STL file format. STL is an acronym for “Standard Triangle Language” or StereoLithography. The model surface in the STL file is created by linking many small triangles.
The number of these small triangles acts as the resolution of the model. The greater the number of triangles, the smoother and more beautiful the surface of the object will be.
However, it should be noted that the more triangles are used, the larger the size of the STL file will be.
Some 3d printers also do not support high resolution, so even if you set up a high-resolution STL file, the machine will not be able to handle it.
Note: The STL file cannot be used to proceed with 3d printing right away. You will need to use slicer software to convert the STL file to G-CODE, a plain text script that tells a 3D printer what to do.
Best free offline (standalone) STL viewer software for Windows OS
Papa’s Best STL Viewer
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Papa’s Best STL Viewer is a super lightweight STL viewer software (only ~60kb after installing).
This software has all the necessary features of STL viewer software such as converting material colors and background.
In addition, you can also add other STL files to the view panel and easily hide or show them through the list tree on the right side of the interface.
You can also switch between 3 different view mode: Solid, Outline, and Wireframe using quick hotkeys F5, F6, F7
In addition to helping you to view STL files quickly and easily, this software also helps you enable thumbnails for STL files.
All in all, Papa’s Best STL Viewer is one of my favorite STL viewer software because of its simplicity and compactness.
Materialise MiniMagics | Free STL File Viewer
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Materialize MiniMagics is a Free STL File Viewer designed to help 3D printing service providers communicate efficiently with account managers and customers.
The software has a streamlined interface but still has all the features needed for an STL viewer software.
You can choose different ways to display the model like Shade, Triangle, Shade&Wire, Wireframe, or Bounding Box, and enable or disable transparency.
The measurements feature makes it easy to measure the lengths of sides, the distances between points, or the circumference and area of circles. You can easily create measurement notes right on the view screen
Cross-section views help you see inside the model easily in the X or Y, Z . axis
When you select a part, the software will display detailed part information such as Dimensions, volume, surface, mesh information (how many triangles and point in mesh). The software even helps you detect bad edges, flipped triangles, and multiple shells automatically.
If you need a software that is lightweight, smooth but full of professional features, Materialize MiniMagics Free STL File Viewer is a very worthy choice.
3D-Tool Free Viewer
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3D-Tool Free Viewer is a tool in the software suite of 3d-tool. This is a relatively professional STL viewer software compared to other software.
This software has a user-friendly interface that supports many different file extensions including 3D design and 2D CAD files.
There are some unique features in this software, such as the Cross section feature.
The Cross Section View allows you to see inside of your model. You can easily adjust the direction and angle of the slicer to view the 3d design in the most comprehensive and detailed way
The Measure markup feature makes it easy to measure the edge length, angle, wall thickness, radius, and diameter of the 3d model. You will love this feature because it helps you to accurately measure the parameters of the 3d print, thereby making the necessary adjustments before proceeding to 3d printing.
The Model Info feature helps you easily calculate the weight, volume, and surface area of the 3d model. The software provides about 30 pre-defined materials for you to choose from. In case your material is not in the pre-defined list, you can easily add new material.
For example, I use Model Info feature and I set my material to ABS and this is what I got:
My model has the following parameters:
| Material: ABS(1.060) Density[g/cm³]: 1.060 X[in]: 17.500 Y[in]: 20.207 Z[in]: 42.000 |
Weight[g]: 52423.578 Volume[in³]: 3018.0 Surface[in²]: 3684.5 Open edges: 0 |
Quick note: the premium version of the software (paid versions) will support more features and file types.
If you only use it to view STL files, the software completely meets your needs because STL viewer is a feature available in the free version.
EasyViewStl
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Easyviewstl is a free STL file viewer that supports 2 languages: German and English. The software has a friendly and intuitive interface, all the features can be easily found on the menu bar and toolbar
Besides basic features such as changing material and background colors, or changing view modes, this software also supports many advanced features required when working with STL files such as Cross-section and automatically finding out errors in the 3D model.
The model statistics panel provides all the necessary information about the model like the number of mesh, points, and triangles.
You can also use Easyviewstl to convert STL files to different 3D file formats like IV, OBJ, OFF, PLY, and VRML97/WRL.
STLView – A Free STL Viewer
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If you are simply looking for a lightweight STL viewer software that has the most basic features like changing material color, background, or changing polygon mode, then STLView is the software you should use.
In the Options menu, you can see all the features of the software such as Change Model Color, Background Color, and change Polygon mode.
Unfortunately, the software does not have the Cross-Section feature that allows you to see inside of the object. If you need to use this feature, you should consider other software.
Paint 3d
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If you are a Windows user, you must have used Paint software. Paint 3d is an upgrade of the old Paint, with basic 3d modeling features. Paint 3d perfectly supports popular 3d file formats such as STL, OBJ…
If you don’t want to install new STL viewer software to view STL files, you can use Paint 3d, a default Windows application, to open STL files.
In addition to being able to view STL files easily, you can also perform basic 3d modeling tasks such as zooming in and out, changing shapes, or adding new shapes, and 3D text to your design.
However, Paint 3d has some limitations such as there are quite a few options for professional editing and you cannot compress files as much as other software. Some users have even complained that Paint 3d slows down their machines.
That’s why I recommend using Paint 3d only as an STL viewer. Take a look at this article if you are looking for a good and free 3d modeling software.
Microsoft 3d Viewer
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Microsoft 3d Viewer is my favorite software in the first place because it is very light and easy to install. You can install the software through the download link above or install it directly through the Microsoft Store. Just search for the keyword 3d viewer and you will find it.
The software interface has 3 main parts:
- (1) Model viewing area.
- (2) the property panel.
- (3) the animation panel.
You can open the STL file by choosing File > Open or more conveniently, drag and drop the file into the interface. If you have set this software as the default application for STL files, just double-click on the STL file to view the STL file.
In the viewing area, you can perform operations such as zoom in, zoom out, and change the viewing angle. In the property panel area, the Environment and Lightning sections have some useful options such as changing the theme, changing light rotation, light color, and environment color.
A pretty useful feature in the Windows 3d viewer is the Stats and Shading section. In this section, you can choose options to display Mesh data, Texture data, and animation data. For example, this is my model after I enable Display triangle mesh data. The software shows that there are 226,880 triangles in this mesh
You can also apply motion to the model in the STL file so you can view the model from different angles
Another feature that maybe not much related to 3d printing but worth mentioning is Mixed reality. This feature allows you to bring 3d objects into the realistic scene through the camera. Take a look at the picture below, a 3d dinosaur placed right in your garden with the Mixed Reality feature.
Gmsh
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Gmsh is a free open-source mesh generator with a built-in CAD engine and post-processor. The software provides a meshing tool with parametric input and advanced visualization capabilities, but this section is not for beginners. If you are interested in meshing features, take a look at their detailed instruction here.
Here’s a quick overview of the software’s modules
Although the software is a meshing tool with a lot of advanced features, you can use Gmsh as a free STL viewer. The software has split-view feature, which allows you to view the model from different angles
ADA 3D
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ADA free stl viewer is a simple and lightweight STL file viewer software, about 500kb in size.
The software has the most basic features to view STL files such as zooming, changing object and background color, and changing view mode.
Users can also view mesh information including Size, vertices, number of triangles on the top right side of the view screen
ADA STL viewer is suitable for users who only need to quickly view the design in the STL file without the need for advanced features such as cross-section or model measurement.
Best free offline (standalone) STL viewer software for MAC
Pleasant3D v2.6
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Pleasant3d is software developed by Eberhard Rensch specifically for the Mac OS X operating system.
Pleasant3d allows you to view and do some minor editing of STL and Gcode files like moving the model to the center of the build platform or a resize.
The software was developed by a user who often 3d printing, so it provides exactly the features that users need in an STL viewer software.
Mac OS X Preview
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You may not know that MAC OS has a built-in stl viewer called MAC OS preview. This is actually a preview application of MAC OS that supports a lot of file formats, not just STL files
This STL viewer for MAC is quite simple and does not support advanced features such as changing material colors, or cross-section. You can just darken the background color to see the 3d model more clearly.
To use this built-in application, just right-click on the stl file you want to view => select Open With => Click Preview
Matt Keeter // fstl
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fstl is a lightweight STL viewer software that works on multiple OS: Mac OS, Windows and Linux. The software is optimized to quickly load and render very high-polygon models.
You don’t need to install this software to use, just right click your stl file and choose Open With, then select fstl as default app for STL file type.
The software is fairly simple, there’s no option to change material color or background color.
Best free online (cloud) STL viewer software
Autodesk Viewer
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Although it is a cloud stl viewer, Autodesk viewer supports many features that are only available in offline software such as Cross-section view, measurements, explode, markup
To start using Autodesk viewer, you will need to create a free Autodesk account. This process just takes a few seconds, after that you can store all your uploaded STL file here to share or view again.
In addition, Autodesk viewer has a setting panel with quite a few tweaks in terms of performance, display such as shading, changing background color, and reflection.
In short, this professional stl viewer covers everything you would look for in an STL viewer.
ViewSTL
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Viewstl.com was created in 2020 to help 3d printing users easily view the design of STL files directly in the browser.
As soon as you visit the website viewstl.com, you will be able to upload your STL file to instantly view the design inside the STL file.
Although just a web-based STL viewer, viewstl.com supports all the necessary features of an STL viewer software. You can change material color, switch between 3 different view modes: flat shading, smooth shading and wireframe.
You can also change model opacity, and change the background color. The info tab also displays model info such as size, number of triangles…
Viewstl also support embed function, which means you can directly embed view screen on your website, read instruction here *(java script knowledge is required).
Tinkercad
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Tinkercad is known as one of the most famous web-based 3d modeling software because of its very user-friendly and easy-to-use interface.
Besides the main 3d modeling feature, Tinkercad can be used as a web-based STL viewer.
You just need to choose Import STL file to Tinkercad to easily view the model.
Tinkercad’s view screen has features that help you easily change the viewing angle, zoom in and out, and change the color of the model.
The limitation of Tinkercad is that the software also does not support cross-section view.
3DViewer.net
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3Dviewer.net is a free and open-source web solution based on three.js library that allow user to view 3D models right in the browser.
This web-based stl viewer works very smoothly, with a minimalistic interface that includes only useful functions for viewing 3d designs. You can either import model from your computer or from a URL.
Measurement tool to easily measure angle and length between points
With model display setting tab, you can change model color, background color, edge color and switch to the dark mode
With 3dviewer.net, you can also export the design to different file types, so it can be used as a 3d file converter.
Lastly, the software is fully open source, so if you are looking to build your own 3d stl viewer you can download source code and learn how to deploy code here: https://github.com/kovacsv/Online3DViewer
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Sharecad is a web-based stl viewer that supports 25 commonly used 2D and 3D formats. Sharedcad’s STL viewer feature in my opinion is a bit limited, only including change view mode (shading, wireframe) and change view angles.
In addition, every time you change view angles, rotate or zoom in, or zoom out the model, it will take a few seconds for the browser to render, so you may feel quite uncomfortable.
Sharecad also support a free iframe plugin that enables viewing drawings on your website
Modelexchange
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Modelexchange allows you to View 3D STL files directly in your browser.
There’s not many functions on this web-base stl viewer. You can view model info, change display mode (3 modes), change material and background color.
Best Android STL viewer app
CAD Assistant
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- Basic tools: changing material color & view angle
- Advanced tools: Clipping plane (cross-section view), measurement tool
Fast STL Viewer
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Fast STL viewer is the most popular stl viewer app on android with over 500k downloads.
This application helps you to view STL files on your android phone, easily rotate, zoom model with swipe gestures on your phone.
There are 4 view mode: Shaded, Combined, Wireframe and Points.
Fast STL viewer is the most popular stl viewer app on android with over 500k downloads.
This application helps you to view STL files on Android phones, easily rotate, zoom models with swipes on your phone.
If your phone is connected to Google Driver, you can directly import the STL file from Google Driver into this application without having to download the file to the internal storage of your device.
exocad webview – Fast STL 3D Viewer
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Exocad webview is a fast and lightweight STL viewer with essential features for viewing stl 3d designs.
There are not many special things about this software, it only supports the most basic features of a software to view stl files on android phones. You can change model transparency as well as display mode, there’s 3 display modes to switch.
Best IOS STL viewer app
STL Simple Viewer
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STL Simple Viewer let you quickly view STL file content on your Iphone or Ipad. You can change model color, change display mode like enable wireframe
There’s a unique feature within this app which allows you to load STL files directly from a Zip file (you won’t need to exact zip file). I love this feature because it’s unconvenient to unzip file on IOS.
Emb3D 3D Model Viewer
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Emb3D 3D Model Viewer is an application that supports cross-platform, from Android to Windows, IOS
Emb3d allows you to preview designs in STL files before proceeding to 3d printing, the software has useful features such as changing Draw mode, change material color, change background gradient, turn on-off light
STL Master
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STL Master is a free software to view stl files on the OS operating system with a special feature that allows you to change the background with your photo.
In addition, this app also supports recording and taking pictures for sharing purposes
Conclusion
Depending on your needs, choose the software that best meets your needs. If your needs are only at the basic level of viewing the design without measuring or using advanced features like cross-section view, then you should use lightweight software like Microsoft 3d Viewer or Papa’s Best STL Viewer.
If you need advanced features, use professional stl viewer software like Materialize MiniMagics | Free STL File Viewer, Autodesk Viewer, CAD Assistant.
Hope my compilation of the best free STL software on different operating systems has helped you find the best free stl viewer software.
