Online STEP File Viewer
Drop a STEP or STP file to view the CAD model in 3D, with its parts and colors, and check its real dimensions. It runs in your browser: nothing is uploaded.
How to open a STEP file online
- 1
Drag your STEP or STP file onto the box above, or click it to choose a file.
- 2
Wait a few seconds the first time: the CAD engine (OpenCascade) is downloaded once and reused for the next files.
- 3
Rotate the model by dragging, zoom with the mouse wheel or a pinch, and pan with the right button or two fingers.
- 4
Switch between front, top, right and isometric views, and turn the wireframe and the grid on or off.
- 5
Check the dimensions, volume and surface area in the measurements panel, and save a PNG image of the view.
What is a STEP file?
STEP (ISO 10303, extensions .step and .stp) is the standard format for exchanging CAD models between programs such as SolidWorks, Fusion 360, Inventor, CATIA, Creo or FreeCAD.
Unlike STL, a STEP file stores the exact geometry of the part (flat faces, cylinders, curves), its units, its colors and how an assembly is made of several parts. That is why suppliers and engineers use it to share designs.
Units and accuracy
STEP files store their units, so the viewer shows the real size of the part whether it was designed in millimeters, inches or meters.
To display it, the exact geometry is converted into a fine mesh of triangles. Dimensions are practically exact; the volume and surface area of curved parts are very close approximations.
Private by design
CAD files are often confidential. Here the file is read by your own browser and is never sent to any server, so you can open supplier or client parts without worrying.
Frequently asked questions
Can I open a STEP file without CAD software?
Yes. This viewer opens STEP and STP files in your browser, without installing SolidWorks, Fusion 360 or any other program.
Are my files uploaded to a server?
No. The file is processed entirely in your browser and never leaves your device.
What is the difference between STEP and STP?
None: they are two extensions for the same format. Both open the same way.
Does it show assemblies and colors?
Yes. Assemblies with several parts are shown complete, with the colors defined in the file, including colored faces.
Why does the first file take longer?
The first time, the browser downloads the CAD engine (about 7 MB). After that it stays loaded and the next files open faster.