Free Online STEP Viewer
Open a .step or .stp file in your browser — no CAD program, no upload. Rotate it, measure it, cut a section and export it as STL or GLB.
What it opens
- STEP files (.step, .stp) from SolidWorks, Fusion, Inventor, FreeCAD, Onshape, KiCad and other CAD tools
- IGES (.igs, .iges) as well
- Assemblies: every part is listed in the scene tree, with the colours saved in the file
- Read by OpenCASCADE compiled to WebAssembly, in your browser — the file never leaves your computer
What you can do with it
- Measure between two points in mm or inches; size, area and volume
- Section view with a clipping plane
- Hide a part or give it another colour in the scene tree; explode an assembly
- Export to STL, OBJ, PLY, glTF, GLB, USDZ, 3MF — STL to print, GLB for the web, USDZ for AR
STEP models of PCBs
Electronics parts and whole boards travel as STEP: KiCad and Altium export a board with its components. Open that STEP here — or open the PCB file itself in the PCB viewer and see the same parts on the board, with nets and the BOM.
Exact surfaces, drawn as triangles
STEP stores exact surfaces (B-rep). To draw them, the viewer turns them into triangles, so a curved face shows fine facets and an exported STL is a triangle mesh of the part — not editable CAD. Editing still needs a CAD program.
Convert a STEP file
The viewer exports to STL, OBJ, PLY, glTF, GLB, USDZ, 3MF. Or go straight to a converter:
Frequently asked questions
Is the STEP viewer free? Do I need CAD software?
It is free, needs no account, and no CAD program — the browser does the work.
Is my STEP file uploaded?
No. OpenCASCADE runs in your browser as WebAssembly and reads the file on your computer; nothing is sent to a server.
Which STEP versions open?
The application protocols CAD tools write — AP203, AP214 and AP242 — and IGES. A file that fails to open usually opens after re-exporting it as AP214.
Can I edit the model?
No — it is a viewer and converter. You can measure, section, hide and recolour parts, scale and export; changing the geometry needs CAD.
How large a file can it open?
Tens of megabytes open on a desktop browser. Big assemblies take longer because the surfaces are turned into triangles on your computer.
What is the difference between STEP and IGES?
Both carry exact CAD geometry; STEP also carries assemblies, colours and product data and is the better choice today. Both open here.
Open your STEP file now
Drop it in the 3D viewer — 13 formats, measure, section and export.
Open the 3D viewer