STEP is an ISO 10303 product-data exchange format used to transfer 3D CAD geometry and product structure between engineering and manufacturing systems. Files commonly use the .step or .stp extension.
Yes. The NS3D STEP Viewer opens supported STEP and STP files directly in a modern browser without requiring specialist CAD software or an account.
No. Supported files are processed locally in your browser and do not need to be uploaded to NS3D.
Yes. Add several STEP or STP files, position and rotate them independently, isolate individual models and fit either the selection or full workspace.
Yes. Use vertex-snapped distances, persistent drawing dimensions and diameter measurements in millimetres or inches.
Where supported data exists in the source file, the viewer preserves part and face colours, displays the component tree and supports exploded views.
Yes. Continue to the linked STEP to STL Converter when you need a tessellated mesh for 3D printing or another mesh-based workflow.
Select a STEP or STP file from your device, or drag it into the viewport. The CAD geometry is processed locally in the browser and converted from its boundary representation into display meshes. Rotate with the left mouse button, pan with the right mouse button and use the wheel to zoom. Fit Model returns the active geometry to the centre of the viewport.
Use Add STEP Files to place several models in the same workspace. Each model can be selected, shown, hidden, isolated, removed, repositioned and rotated independently. Fit Selected frames the active model, while Fit All includes every visible model. This is useful for visual comparison, layout checks and measuring between separate imported components.
The component tree exposes supported assembly and part relationships, while the information panel reports vertices, triangles and overall dimensions. Source part and face colours are retained where the STEP data provides them. Wireframe view reveals the generated tessellation and exploded view separates supported assembly components. STEP is part of the ISO 10303 family for product-data exchange; further background is available from the NIST STEP overview.
Measure Distance creates a temporary two-point check. Add Dimension retains an engineering-style dimension, and Measure Diameter creates a diameter annotation from supported snapped geometry. Measurements snap to tessellated vertices and can be displayed in millimetres or inches. Existing annotations update when the unit setting changes and remain visible in screenshot export.
STEP normally preserves engineering geometry more effectively than a mesh format, but most slicing workflows require STL or another tessellated format. Use the STEP to STL Converter below when a mesh export is required, then open the STL Viewer or STL Repair tool to inspect print scale and mesh condition. Retain the original STEP file because conversion to STL does not preserve the full product structure, exact surfaces or CAD feature history.
Supported files are processed on the current device without an account or server upload. STEP is a broad standard and files can vary by application protocol, exporter and included product data. The viewer focuses on supported geometry, hierarchy and appearance used for browser-based inspection; it is not a replacement for the originating CAD system or a controlled drawing.