Online STEP / STP CAD Viewer
Inspect engineering STEP and STP solids and assemblies directly in your browser. Powered by OpenCascade WebAssembly with 100% client-side privacy.
Drag & drop your STEP / STP file here
or click below to select from your device (100% private, zero uploads)
STEP / STP Technical Specifications & Guidelines
In-depth technical reference for ISO 10303 Product Model CAD Solid.
| Supported Extensions | .step, .stp |
| Format Category | Mechanical CAD & Solid Modeling |
| File Encoding | ISO 10303-21 Clear Text Physical File |
| Compatible CAD & 3D Software | SolidWorks, Autodesk Inventor, Siemens NX, PTC Creo, CATIA, FreeCAD |
| Standard Compliance | ISO 10303-21 (STEP Physical File format AP203, AP214, AP242) |
| Geometry Engine | OpenCascade Technology (OCCT) compiled to single-threaded WebAssembly |
| Color & Topology | Retains per-face and per-solid colors, assembly hierarchies, and part names |
| Conversion Options | Export directly to GLB, OBJ, STL, or USDZ in-browser |
STEP / STP Frequently Asked Questions
Everything you need to know about opening, inspecting, and converting STEP / STP files in your browser.
How does Universal 3D Viewer render STEP files without a backend server?
We compile the industrial OpenCascade Technology (OCCT) CAD geometric modeling kernel into WebAssembly (WASM). When you drop a .step or .stp file, the WASM kernel runs client-side in your browser tab, tessellating B-Rep NURBS surfaces into GPU meshes locally. Very large assemblies can take a while, because the kernel is single-threaded.
Can I inspect inner chambers and cross-sections of a STEP assembly?
Yes. You can activate the Cross-Section Clipping tool to slice through solid assemblies along the X, Y, or Z axis in real time, exposing internal tolerances, wall thicknesses, and hidden sub-components.
Which STEP application protocols are supported?
Universal 3D Viewer supports AP203 (Configuration Controlled 3D Designs), AP214 (Automotive Mechanical Design Process), and AP242 (Managed Model-Based 3D Engineering) geometry, colors and assembly structure.
Are large STEP assemblies kept secure and private?
Yes. Because processing is 100% client-side with WebAssembly, your model files never leave your device: no geometry, metadata or proprietary data is transmitted.
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