IGES is one of the oldest neutral CAD exchange formats, dating back to 1980. It represents models as surfaces and curves rather than watertight solids, and although STEP has largely replaced it, IGES files remain everywhere in legacy archives, tooling data and supplier exchanges.
IGES files come out of older CAD and CAM systems and out of long-lived supplier archives: mould and tooling surfaces, legacy mechanical parts, and exports made by systems that are now decades out of support. The format dates from 1980 and refuses to die because everything can still read it.
Best for: Opening legacy CAD data and surface models from older systems. There is a fuller write-up on the IGES format reference page.
Every format on this site also gets the same viewport tools: orbit, pan and zoom with fit-to-view, isometric and the six standard views, a perspective/orthographic toggle, shaded, shaded-with-edges, wireframe and X-ray display, hide-selected, and a PNG screenshot of the current view. The same controls are on the general 3D and CAD viewer, which accepts every importable format at once.
Worth knowing before you rely on it. A viewer that overstates what it can read wastes more of your time than one that is specific about its limits.
| IGES files | |
|---|---|
| Extensions | .iges, .igs |
| Geometry | B-rep surfaces & curves |
| Units | Yes, embedded |
| Colors & materials | Limited |
| Animations | No |
| Typical use | Legacy CAD exchange |
IGES carries its units in the file header, and the kernel is asked for millimetres, so the dimension readout is in real millimetres.
IGES is read-only here. If you need to keep working with the geometry, tessellate it into a mesh format first. The converter runs on the same local pipeline as this viewer, so a conversion is just as private as a preview: IGES to STL is the usual choice.
This page can: it reads IGES with a full CAD kernel in your browser and gives you shaded, wireframe and X-ray display, section planes and measurements. No CAD licence and no install are involved.
Almost always because the IGES file contains only curves, points or wireframe entities. There are no surfaces to tessellate, so there is nothing to shade. Re-export from the source system with surfaces or solids included.
IGES stores independent trimmed surfaces, and small gaps between adjacent patches are a normal translation artefact. They are in the file rather than in the viewer, which is precisely why STEP replaced IGES for solid exchange.
No. Parsing happens in your browser through WebAssembly. Nothing about the geometry is transmitted, so old supplier data can be opened without a review.
Geometry: b-rep surfaces & curves. Units: yes, embedded. Colors and materials: limited. Animations: no. Of that, the viewer draws geometry and flat base colors; texture maps and animation are never displayed. IGES carries its units in the file header, and the kernel is asked for millimetres, so the dimension readout is in real millimetres.
Read the IGES format reference for the format itself, open the general 3D and CAD viewer if you have several formats to look at, or start from the 3D and CAD converter.
If the model is heavier than it needs to be, the mesh simplifier reads .iges directly, tessellating the CAD geometry first, decimates it in your browser and previews the result before you export. If the file is headed for a 3D printer, the G-code viewer shows the sliced toolpath layer by layer once your slicer has run.
IGES and STEP both move CAD data between systems, but they are generations apart. When IGES still appears, why STEP usually wins, and how to convert both for free.
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