Free Online CAD Viewer for the 3D Printing & Prototyping
A lightweight, online tool to convert 3D file like the Custom Spacer—anytime, anywhere, without installing any software.
Drag & drop your 3D files
Supported formats: STEP (.step, .stp), IGES (.igs, .iges), STL (.stl), PLY (.ply), OFF (.off), BREP (.brp, .brep)
File stay private
Automatically deleted after 24hrs
add upto 300MBCustom Spacer Essentials
The Custom Spacer is a key part in the 3D printing and prototyping workflow. CAD formats like STEP, IGES, BREP, STL, OBJ, PLY enable rapid modeling, printing, and iteration of this component. This part is commonly used to evaluate design aesthetics, mechanical fit, or test functional attributes before final production. With Marathon-OS, teams can collaborate in real-time, manage multiple iterations, and maintain complete traceability across the prototype lifecycle.
Used forFit testing
Common CAD File FormatsSTL, OBJ, STEP
Who uses CAD files?
Product DesignersR&D EngineersPrototype TechniciansNeed CAD access
Marketing TeamsClientsBusiness AnalystsWhy they cant view CAD files?
Clients and marketing teams are left out of early 3D design discussions due to lack of CAD tools or skills. They often see final outputs instead of contributing during ideation, which delays feedback and increases iterations.
The Solution: Marathon-OS CAD Viewer
Why Choose Marathon OS CAD Viewer?
Marathon OS CAD Viewer renders any CAD file instantly with a proprietary engine, ensuring seamless, lag-free visualization—no matter the model size.
Lightning-Fast Rendering
Marathon OS optimizes real-time CAD visualization with smooth performance, even for large and intricate models.
Supports Multiple Formats
View STEP, IGES, STL, BREP, and more with precision and clarity—right in your browser.
No Installation Required
Skip heavy software—just upload and start viewing instantly.
Cloud-Based & Secure
Files stay private and automatically delete after 24 hours for security.
Engineered for Professionals
Designed for engineers, manufacturers, and designers needing quick, high-quality CAD previews.
Essential Features of Marathon OS CAD Viewer
Effortlessly upload and view CAD files with a high-speed, secure, and scalable tool. Experience smooth, real-time rendering—no software installation required.
Seamless CAD File viewing
View STEP, IGES, STL, BREP, OBJ, PLY, OFF, and more—instantly and without setup delays.
Handles Large & Complex Models
Optimized to convert even intricate engineering models with accuracy and speed—no matter the size or complexity.
No Installation Required
view 3D files directly from your browser. no plugins—just drag, drop, and go.
Secure & Privacy-Focused
Your files are encrypted during upload, processed securely, and automatically deleted after 24 hours to protect your data.
FAQ
Find answers to common questions about Marathon OS CAD Viewer. Whether you're getting started or looking for advanced features, we've got you covered.
What is Marathon OS 3D CAD File Viewer?
What file formats are supported?
Is Marathon OS 3D File viewer free to use?
How is my data stored and secured?
Do I need any special software or training?
Can I view large and complex CAD models?
Simplifying Cloud PDM & PLM