Question 1

How do I open a STEP file without CAD software?

Accepted Answer

Drop the .step or .stp file on the free Online 3D Viewer at https://tool.adjiebrotots.com/online-3d-viewer/. OpenCascade, running in your browser, reads the exact CAD surfaces and shows the part or assembly in 3D with its colours, so no CAD licence or install is needed.

Question 2

Is my 3D model uploaded to a server?

Accepted Answer

No. The Online 3D Viewer reads the file inside your browser, so the model never leaves your device. Only the free reader libraries are downloaded, once, from a public CDN.

Question 3

Which 3D file formats can it open?

Accepted Answer

CAD files: STEP (.step, .stp), IGES (.igs, .iges), OpenCascade BREP and Rhino 3DM. Meshes: STL (ASCII and binary), OBJ with MTL and textures, 3MF, AMF, PLY (including point clouds), OFF and 3DS. Scenes: glTF and GLB (with Draco, Meshopt and KTX2 compression), FBX, COLLADA (.dae), USDZ, USDA, USDC and VRML (.wrl).