Your model stays on your device
The selected file is read into browser memory and parsed locally. This viewer does not upload the model file to Nox servers or save a server copy.
How to view a STEP or STP file online
Step 1
Choose a model
Drop a .step, .stp, or .stl file onto the viewer, or select one from your device.
Step 2
Let the browser parse it
The model is read and processed locally in browser memory. It is not sent to a Nox upload endpoint.
Step 3
Inspect the preview
Drag to orbit, use the wheel to zoom, right-drag to pan, and review the X, Y, and Z bounding box.
Viewer controls and features
- Interactive orbit, pan, and zoom controls
- Overall X × Y × Z bounding-box dimensions
- Inch and millimeter display toggle
- Reset-view and open-another-file controls
- STEP, STP, and STL visual previews
- No account, desktop install, or model upload
The bounding box is the model's overall axis-aligned envelope. It is useful for a quick size check, but it is not a substitute for inspecting individual faces, holes, tolerances, or manufacturing annotations in CAD software.
Supported file formats
| Format | Extensions | What this viewer does |
|---|---|---|
| STEP | .step, .stp | Interactive triangulated preview of supported model geometry and its overall bounding box. |
| STL | .stl | Interactive triangle-mesh preview. Verify scale against the source because STL files do not provide dependable unit metadata. |
| Other CAD formats | IGES, OBJ, native CAD | Not accepted by this viewer. Export a compatible STEP, STP, or STL file first. |
Local processing and CAD-file privacy
When you choose a file, the browser reads its bytes and runs the geometry parser on your device. The viewer does not post the selected model to a Nox API, create a public link, or retain a copy after the page is closed.
Local processing reduces unnecessary transfer of design data. Your browser, device, extensions, and organizational security policies still apply, so regulated workflows should follow their own approved handling requirements.
STEP, STP, and STL explained
STEP and STP
STEP is the common name for the ISO 10303 product-data standards. ISO 10303-21 defines a clear-text exchange structure, and .step and .stp are conventional extensions for files that use it. The two extensions do not identify different geometry formats.
STEP versus STL
STEP is intended to exchange structured product data and may contain parts, assemblies, and manufacturing information depending on the application protocol and exporter. STL describes an object's surface as triangles. This viewer renders both as interactive previews but does not convert between them.
Technical references: ISO 10303-21, NIST's STEP overview, and the Library of Congress format description.
What this browser viewer does not replace
Preview limitations
- Read-only display; it does not edit or repair model geometry.
- No feature tree, assembly browser, part names, BOM, PMI, or GD&T inspection.
- No point, edge, hole, angle, volume, or surface-area measurement.
- The displayed mesh is a visual preview, not a manufacturing validation.
If a file will not load
- Confirm the filename ends in .step, .stp, or .stl.
- Try a current browser with WebGL enabled.
- Re-export the model from its source CAD application.
- For a large assembly, close other heavy tabs or test a simplified export.
Frequently asked questions
What is a STEP file?
STEP is a family of ISO 10303 standards for representing and exchanging product data. Files commonly use the .step or .stp extension. This viewer converts supported model geometry into an interactive browser preview.
Are STEP and STP files the same?
Yes. .step and .stp are common filename extensions for the same STEP Part 21 exchange format. Renaming the extension does not change the model data inside the file.
Is my STEP file uploaded or stored?
No. The selected file is read into browser memory and parsed on your device. This viewer does not upload the model file to Nox servers or save a server copy.
Can I view a STEP file without CAD software?
Yes. You can inspect the model, orbit, pan, zoom, and read its overall bounding box without installing a desktop CAD package. Editing and manufacturing validation still require appropriate CAD or inspection software.
Can this viewer measure a STEP model?
It reports the axis-aligned X, Y, and Z extents of the model. It does not provide point-to-point, hole-diameter, angle, tolerance, or GD&T inspection tools.
Does the viewer support STEP assemblies?
It can preview geometry returned from files with multiple meshes, but it combines that geometry for display. It does not expose an assembly tree, part names, a bill of materials, or product manufacturing information.
What is the difference between STEP and STL?
STEP is designed for product-data exchange and can carry structured geometry and other engineering information. STL describes a surface as a triangular mesh. This tool previews both, but it does not turn an STL mesh into editable STEP geometry.
Why will my STEP file not open?
The file may be empty, damaged, use unsupported content, or require more browser memory than is available. Try re-exporting it as a standard .step or .stp file, using a current browser, or testing a smaller model.