Open and view STEP files online — free, no signup, no upload
A STEP file (ISO 10303, .step/.stp) is the universal CAD exchange format for solid models. Unlike a mesh, it stores exact boundary-representation geometry, so it's what SolidWorks, Fusion 360, CATIA and Onshape read and write. This viewer opens STEP files right in your browser so you can rotate, zoom and pan a model and check its bounding-box dimensions and triangle count — without installing software or sending your file anywhere.
How to view an STEP file
1. Drag your file onto the box above, or click Open STEP file. 2. Drag to orbit, scroll to zoom, right-drag to pan. 3. Read the width/depth/height and triangle count in the panel.
Frequently asked questions
How do I open a STEP file online?
Drag your .step or .stp onto this page or click Open File. It's read by an OpenCASCADE engine running in your browser and rendered in 3D — nothing is uploaded. The first STEP you open loads the engine (a one-time few-second download).
Is STEP the same as STP?
Yes — .step and .stp are the same format; the extension just differs by system. This viewer opens both.
Do I need CAD software like SolidWorks?
No. The STEP geometry is tessellated and displayed right in your browser, so you can inspect a model without any CAD program installed.
Is my STEP file uploaded?
No — the whole thing runs on your device. Your CAD model never leaves your computer.