Free online STEP and IGES viewer
Last updated: 21 October 2026
DIMview opens STEP and IGES files in your browser, so you can look at a CAD part or assembly without a CAD program and without sending the file anywhere.
Open a STEP or IGES file
- Open DIMview with the button below.
- Drag the file onto the page, or press the open area and choose it. The extensions .step, .stp, .stpz (zipped STEP), .iges, .igs and .brep are recognised.
- Wait a moment while the shape is converted to a mesh. Orbit with the left mouse button, pan with the right one and zoom with the wheel.
The conversion is done by OpenCascade, the open source geometry kernel behind FreeCAD, compiled to WebAssembly and run in a background worker. The CAD solids are turned into a triangle mesh for display, so curved faces are shown as many small flat facets.
What you can do with the model
- Measure. Click two points. DIMview snaps to vertices, edges and edge midpoints, and shows the distance together with the X, Y and Z differences.
- Measure from the origin and measure the angle between two lines, with the origin axes available as lines.
- Cut sections along the X, Y and Z axes to look inside a part.
- Change the view: wireframe, perspective or orthographic, the view cube, and a grid you can switch off.
- Print the view with its measurements, using Ctrl+P.
Millimetres are assumed for STEP and IGES files, which is what almost all mechanical CAD exports use. The Units list in the status bar changes how measurements are shown. Z is up, as in the CAD program that exported the file.
Privacy
The file is read by your browser and is not uploaded. That is the reason many engineers use DIMview for parts they are not allowed to send to an online converter. Our visitor statistics count page views without cookies and never see the file (privacy policy).
What DIMview does not do
DIMview shows the geometry. It does not show the feature tree, parametric dimensions or tolerances stored in the file, and it does not edit or convert the model to another CAD format. If you need an STL for 3D printing, export it from your CAD program.
Questions
Is the STEP viewer free?
Yes. There are no ads, no account and no time limit.
Why does a curved face look faceted?
The solid is converted to triangles before it is drawn. Measurements snap to the vertices and edges of that mesh, so for small radii treat the result as an approximation of the CAD value.
Can I look at the parts of an assembly one by one?
Each solid in the file is a separate element in the Tree panel, so you can hide or isolate it. The assembly structure and part names of the CAD program are not shown.