The STEP file format stands for the “standard for the exchange of product model data”, and it’s an ISO-standardized file format for CAD design. You might have also seen it referred to as “STP”, and that’s because it uses the file extensions “.step” and “.stp” interchangeably.
STEP files stand out for their high fidelity and transferability, requiring minimal conversion between different programs. As such, they’re a popular choice for sharing editable 3D files, preserving geometric accuracy despite numerous changes of hands.
In this article, we explore ways of viewing these versatile STEP files, whether for inspection or to provide visualizations for clients. But before we get started, let’s first take a look at what it is that makes a great STEP file viewer.
Considerations
We’ll be focusing primarily on viewing STEP files as opposed to editing them. Towards that end, here are some items we took into consideration:
- Free or competitive pricing: Simply viewing a file shouldn’t require expensive software. As such, we’ve prioritized programs that are free or have free versions. Of course, if you’re looking for more advanced features, we’ve highlighted paid premium options as well.
- Easy to use: In the same vein as pricing, we’re looking for software that makes it easy to view your files. Depending on your uses, what’s “easy” may look different. To that end, we’ve covered everything from the most bare-bones options to advanced, enterprise-grade tools, each at the appropriate ease of use for their target audience.
- Helpful additional features: Some users may only want to view their files, but others may be looking for additional embedding, editing, and inspection options. Thus, we cover a range of tools from basic, browser-based viewing to advanced metrology and CAD software.
With that, let’s get into our top picks for the best STEP file viewers!
Offline Options
These first options consist of software that can not only open and view STEP files, but also likely have additional features to allow editing, measurements, and several other inspection tools.
ABViewer
Developed by CADSoftTools, ABViewer is a graphic design and drawing software that’s compatible with over a hundred different file formats, including 3D model formats like STEP. While ABViewer’s user interface looks a bit archaic, the software is still actively updated to patch bugs and add new features.
ABViewer is packed with visualization and editing tools that you can use to inspect and even modify elements of your imported STEP model. Perhaps most importantly, the rendering for STEP files on ABViewer looks spectacular, and you can even adjust the model shading, display the wireframe, and change the background color.
Other tools on ABViewer allow you to measure segments of your model and compare designs side-by-side; there’s even a command line feature for running scripts. ABViewer also allows you to export models in the STEP format, which might be useful if you need to make an adjustment to a model and then move it to a different platform (e.g. special CAD software).
- Price: 30-day free trial; $73 for a lifetime Professional license
- OS: Windows
- Where to find it? CADSoftTools
- Developer: CADSoftTools
FreeCAD
FreeCAD is feature-rich CAD software with STEP-viewing capabilities. Beyond the basic viewer, FreeCAD offers general-purpose parametric modeling for a wide range of users.
This free program is capable of both 2D and 3D modeling, with powerful plug-ins for additional functionality, including finite-element analysis, CAM and CNC, robot simulation, and rendering tools. While the layout may be overwhelming at first, FreeCAD’s many functions are for those who want more than just simple STEP file viewing. To help you get started, we have a handy tutorial on FreeCAD’s basics.
- Price: Free
- OS: Windows, MacOS, Linux
- Where to find it? FreeCAD
- Developer: FreeCAD (with other sponsors)
PrusaSlicer
If you have a 3D printer, then you’ve probably heard of PrusaSlicer, the free, popular 3D slicer software developed by Prusa Research. As a 3D slicer, PrusaSlicer is home to hundreds of print settings that enable the software to convert digital models into 3D printable G-code files. And, unlike most other slicer software (e.g. Cura), PrusaSlicer supports the STEP file format.
Unfortunately, PrusaSlicer only allows you to import STEP files, not export them. However, it’s still a great platform for visualizing STEP models, especially if you plan on 3D printing them. On this note, if you plan on 3D printing your imported STEP file, you can use PrusaSlicer’s basic modeling tools (e.g. scale, rotate, move) before slicing the model. Lastly, it’s worth mentioning that PrusaSlicer has a terrific user interface that’s easy to use and no special steps are required for importing STEP models.
- Price: Free
- OS: Windows, Mac, Linux
- Where to find it? Prusa
- Developer: Prusa Research (with help from the community; open-source)
Fusion 360
Autodesk’s Fusion 360 is a fully-featured parametric CAD tool. A popular choice for students and professionals alike, the software includes rendering, CAM, FEA, mesh modeling, surface modeling, PCB design, and more.
With a full CAD program like Fusion 360, you can view your STEP files and decide how you want to edit them with incredible flexibility. As such, Fusion is an excellent tool for anyone incorporating STEP files into a larger workflow, from design to fabrication.
- Price: Free for students and educators; ~$550/yearly for commercial use
- OS: Windows, MacOS
- Where to find it? Autodesk
- Developer: Autodesk
GOM Inspect
GOM Inspect is more than just a STEP file viewer, it’s a full metrology package, with volume, surface, and shape inspections alongside file comparisons. From there, you can generate detailed reports on the inspection results, as visualized above.
This professional tool is free, but you can contact GOM for a paid version that has additional functionality including opening more file formats, digital assembly capabilities, scripting, and parametric inspection for more advanced users. If you’re simply looking to view your STEP files, GOM Inspect Suite may not be the best choice since it offers such powerful functionality. However, if you need to tackle other complex tasks in the inspection process, it may be your perfect solution. Just be aware that there’s a steep learning curve involved.
- Price: Free for the basic version; contact GOM for Pro plan pricing
- OS: Windows
- Where to find it? Zeiss
- Developer: Zeiss
Online Options
These tools can be used straight in your browser, no matter which OS you have. While they may not be as decked out with features as some of the software above, if you are just looking for something quick and simple to open a STEP file, it doesn’t get easier than these options!
eMachineShop
A terrific (and free) online option for viewing STEP files is eMachineShop. Unlike many of the other options on this list, eMachineShop isn’t a site dedicated to opening and viewing files. Instead, it’s an on-demand manufacturing service with a terrific built-in STEP file viewer. And, if you’re interested in ordering your imported STEP 3D model, you can do so directly through the viewer by clicking the “Price Quote” button and then specifying the material, manufacturing process, and other options.
As file viewing isn’t the main purpose of eMachineShop, it makes sense that the features are a bit limited. However, there are still some useful tools on the site, including the ability to export files (as a 3D model or image), change the background color, and set the units.
- Price: Free
- Where to find it? eMachineShop
- Developer: eMachineShop
3D Viewer Online
3D Viewer Online is a web service dedicated to providing easy viewing of 3D files. The free offering gets you everything you need for basic STEP viewing, packaged into a clean and user-friendly interface.
Where the service really shines, however, is in their paid premium and business plans. There, you’ll find a much wider range of upload and rendering settings with advanced, seamless embedding. This allows you to integrate 3D views directly into your website for users to interact with, a valuable feature for those looking to share 3D views of their STEP files.
- Price: Free for general users, or ~$15/month for a premium plan (billed annually)
- Where to find it? 3D Viewer Online
- Developer: 3D Viewer Online
Autodesk Viewer
Autodesk Viewer is a formidable web-based service offered by software giant Autodesk. Here, we’re beginning to see features that extend beyond simple viewing and sharing of STEP files.
Aside from the basic zoom, pan, and orbit, a unique first-person view is included for navigating 3D scenes. In addition, you have options to make measurements, build section and exploded views, create markups, write comments, and take screenshots. Every view is automatically saved to your Autodesk account, so they’re easily managed and shared via the cleanly-designed dashboard.
- Price: Free
- Where to find it? Autodesk
- Developer: Autodesk
Onshape
Onshape is a professional, enterprise-grade CAD tool. It has everything you would expect from CAD software, granting you the freedom to view and edit STEP files as you wish.
What makes Onshape stand out is its emphasis on collaboration. Designed to be used by teams of people, it allows easy tracking of file versions and the like, perfect for larger corporations. It’s also browser-based and can be accessed from a variety of devices, including your phone.
- Price: Free (non-professional), commercial-use plans from $1,500/ year
- Where to find it? Onshape
- Developer: PTC
ShareCAD
ShareCAD is as straightforward as STEP file viewers get: simply upload your file and it loads the model directly in your browser. From there, you have bare-bones navigation and shading tools, along with basic sharing and embedding options.
While the interface may not be as clean as other options on this list, it’s quick to learn. No account is needed either, making ShareCAD an excellent option for those who just want a quick, no-hassle visualization of their file.
- Price: Free
- Where to find it? ShareCAD
- Developer: CADSoftTools
License: The text of "The Best STEP File Viewers of 2023 (Online & Offline)" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.