Free STEP File Viewer Online
Open a STEP (.step, .stp), IGES, STL or OBJ file in your browser — free account, no CAD software. Rotate, zoom and inspect the part in 3D, with its size, solid count and weight. Sheet-metal parts also get a fabrication BOM (gauge, flat blank, bends).
Part summary
STEP, STL or IGES: what the viewer shows
STEP / STP
Exact solids from SolidWorks, CATIA, Inventor, Fusion, Creo or NX. Each body is a separate part, with its size and weight from the true volume.
IGES / IGS
The older neutral format, still common from legacy CAD and suppliers. Opens the same way as STEP.
STL / OBJ / PLY
Triangle meshes from 3D printing and scanning. You can rotate and measure them; weight is estimated from the mesh volume.
Quoting a sheet-metal part? The STEP to BOM tool reads gauge, flat-pattern blank, bends, strip layout and scrap from the same file. Got a 2D drawing instead? Convert PDF to DWG.
Frequently asked questions
How do I open a STEP file without CAD software?
Drop the .step or .stp file on this page and sign in (or create a free account). It is converted on Aginera’s OpenCascade service and opens as an interactive 3D model — drag to rotate, scroll to zoom. Nothing to install. The sample part on this page opens without an account.
Which file types can I view?
STEP (.step, .stp), IGES (.iges, .igs), STL, OBJ, PLY and GLB. STEP and IGES keep each solid as a separate part, so multi-body files and assemblies show their part count.
Is the STEP viewer free?
Yes. Viewing your 3D file, its bounding size, solid count and estimated weight is free with a free account, as is the fabrication BOM for sheet-metal parts (gauge, flat-pattern blank, bends, strip layout, scrap); downloading that BOM is $5 per part.
Is my file kept private?
Your part is stored in your own private project in your Aginera account and is not shared.
What is a STEP file?
STEP (ISO 10303, .step or .stp) is the neutral 3D CAD exchange format. SolidWorks, CATIA, Inventor, Fusion, Creo, NX and Onshape all export it, which is why suppliers and machine shops receive parts as STEP. Unlike STL it stores exact solid geometry (faces, edges, curves), not just triangles.