Which CAD file formats can this viewer open?

This page accepts STEP and STP files using the ISO-10303-21 exchange format. It does not currently open DWG, DXF, IGES, SolidWorks, NX, CATIA, Creo, or Revit files.

Is this an exact CAD or measurement viewer?

No. The tool tessellates supported CAD geometry for visual display and reports millimeter bounding-box dimensions. It does not provide exact surface inspection or manufacturing-grade measurement.

Is my STEP file uploaded?

No. The file is read and tessellated in a dedicated browser worker. BaseToolbox does not upload or store the model.

Why can a valid STEP file still fail to open?

Preview cost depends on CAD face count, model complexity, and generated triangles. The tool stops at its file, face, triangle, or time limits instead of risking an unresponsive browser.

STEP File Viewer - View STEP and STP Online

Open and inspect a STEP or STP CAD file locally in your browser. The viewer tessellates supported geometry for 3D display, and your file is not uploaded.

Drag and drop a STEP or STP file here

Accepts one .step or .stp file

Choose file

Maximum file size: 20.00 MiB. The CAD engine starts only when you select Preview.

Lighting

StudioBright

STEP geometry

Geometry statistics appear after a successful preview.

Browser-local STEP viewing

Your file is read in a dedicated browser worker. BaseToolbox does not upload or store it, and the CAD engine loads only when previewing starts.

Browser safety limits

Each preview stops after 30 seconds, or if tessellation produces more than 100,000 triangles. Complex assemblies may reach a limit even when the file is under 20 MiB.

A visual mesh preview, not a CAD editor

The viewer tessellates supported bodies and displays a flattened mesh in millimeters. It does not preserve assembly hierarchy, part names, PMI, parametric features, modeling history, materials, tolerances, or analytic surfaces, and it is not a manufacturing-grade measurement tool.

View STEP and STP files locally in your browser

This STEP file viewer reads supported CAD geometry in a dedicated browser worker, normalizes declared model units to millimeters, tessellates the geometry, and renders the resulting 3D preview without uploading the source file.

How to preview a STEP file online

Choose one STEP or STP file up to 20 MiB. The file remains on your device.
Select Preview to load the local CAD engine and tessellate supported geometry in a background worker.
Rotate, pan, zoom, switch lighting, inspect bounds and geometry counts, or save a PNG screenshot.

What the STEP preview does not preserve

The displayed result is a tessellated and flattened visual mesh. It does not expose an assembly or part tree, PMI, exact analytic surfaces, editable features, modeling history, materials, tolerances, section analysis, or manufacturing-grade precise measurement.

Related CAD and 3D tools

Convert STEP or STP to STL Open the general 3D Model Viewer

STEP file viewer FAQ

Which CAD file formats can this viewer open?: This page accepts STEP and STP files using the ISO-10303-21 exchange format. It does not currently open DWG, DXF, IGES, SolidWorks, NX, CATIA, Creo, or Revit files.
Is this an exact CAD or measurement viewer?: No. The tool tessellates supported CAD geometry for visual display and reports millimeter bounding-box dimensions. It does not provide exact surface inspection or manufacturing-grade measurement.
Is my STEP file uploaded?: No. The file is read and tessellated in a dedicated browser worker. BaseToolbox does not upload or store the model.
Why can a valid STEP file still fail to open?: Preview cost depends on CAD face count, model complexity, and generated triangles. The tool stops at its file, face, triangle, or time limits instead of risking an unresponsive browser.