Free STEP file viewer for your browser
Drag a .step, .stp, .iges or .igs file into your browser and see it instantly. No AutoCAD, Fusion 360 or SolidWorks install required. Works the same on phone and desktop.
What you can do with it
- Open STEP (.step, .stp) and IGES (.iges, .igs) files — the two main CAD interchange formats
- Orbit, pan, zoom with mouse or touch
- Measure real-world distances in millimetres
- Cross-section any axis to inspect internal geometry
- Solid, wireframe, X-ray and matte view modes
- Screenshot or rotating GIF capture for documentation and sharing
- Works in any modern browser — Chrome, Firefox, Safari, Edge
For when you don't want to install CAD software just to look at one file
The typical reason someone opens a STEP viewer: a vendor or supplier sent a .step, you are not at your CAD workstation, and you do not want to install Fusion 360 or SolidWorks on whatever machine you happen to be using. The viewer at open3d.app handles that case in one step — drop the file into the page, see the model.
Equally useful for Fusion 360, SolidWorks and Onshape users who export STEP to share with clients or contractors who don't have CAD installed. Send the link, drag the file in, the recipient sees the model immediately.
Privacy: STEP files stay on your device
STEP files are often confidential — vendor parts, supplier designs, work-in-progress assemblies. The viewer is a static page that parses everything locally in your browser. Nothing is uploaded, nothing is logged, the file never leaves your device.
FAQ
Do I need AutoCAD, Fusion 360 or SolidWorks installed?
No. The viewer runs entirely in your browser. You can open a STEP file from a vendor, client or supplier without any CAD software installed on your machine.
What is the difference between .step and .stp?
They are the same format with two common file extensions. STEP (.step) is the full name; .stp is the short version used on Windows systems for the 3-character extension limit. The viewer reads both interchangeably.
Does it open IGES files too?
Yes. Both .iges and .igs are supported in the same viewer. IGES is the older CAD interchange format, still used by some industries.
Can it edit STEP files?
No. It is a viewer only — orbit, measure, cross-section, screenshot, but no editing. For editing you still need a CAD package like Fusion 360, SolidWorks, Onshape, or the free FreeCAD.
How big a STEP file can it handle?
For most everyday parts and small assemblies the viewer is comfortable. Very large assemblies with thousands of unique bodies may take longer to tessellate. A quick test: drop a file in, give it 5–15 seconds, see if it opens. If it does not, drop us a note.
Does my STEP file get uploaded anywhere?
No. The viewer is a static page and your file is parsed locally in your browser. Useful for confidential vendor or client STEP files that you do not want to upload to a cloud service.