Free online IGES to SKP converter

Engineering suppliers often deliver parts and surfaces as IGES files, while SketchUp projects require SKP for editing, layout, or presentation. Converting the model lets a SketchUp project include CAD-supplied mechanical parts, architectural components, or legacy geometry.

What the IGES format is

IGES (Initial Graphics Exchange Specification), usually stored as .igs or .iges, is a neutral CAD exchange format used by mechanical engineers, manufacturers, architects, and industrial designers. It transfers wireframes, curves, surfaces, trimmed surfaces, and, depending on the exporting system, solid-related boundary data between CAD applications.

IGES files commonly originate in CATIA, SolidWorks, Siemens NX, Creo, AutoCAD, Rhino, and other engineering CAD systems. The format does not preserve the source application's parametric feature tree, constraints, or normal editing history, so the recipient receives exchange geometry rather than a native CAD model.

What the SKP format is

SKP is SketchUp's native project format. It can store SketchUp geometry, groups, components, materials, tags, scenes, camera settings, and model units for architectural visualization, interior design, construction layouts, and lightweight 3D presentations.

SKP is convenient to edit in SketchUp and can be easier to share for presentation work than an engineering CAD file. It is not a feature-based replacement for IGES: imported CAD surfaces must be converted into SketchUp faces, and the resulting file will not contain the original parametric operations.

How to convert IGES to SKP

Rhino is the most direct desktop option because it can import IGES and export SketchUp format without an intermediate file.

1. Open Rhino and choose File → Open or File → Import, then select the .igs or .iges file.
2. In the IGES import options, preserve the source units when they are reliable. If the file has no dependable unit information, record a known dimension before continuing.
3. Inspect the imported geometry. Use Rhino commands such as What, ShowEdges, and Join to identify separate surfaces, naked edges, and invalid or duplicated geometry.
4. Repair gaps and remove construction geometry as needed. Use Join only for surfaces with matching edges, and use Cap only when planar openings should safely become closed ends.
5. Select the required objects and choose File → Export Selected. Export the file as SketchUp (*.skp). Export the complete model instead if no selection is active or if the whole scene is required.
6. Set the required SKP version, units, and mesh quality in Rhino's SketchUp export options. A finer mesh represents curved surfaces more closely but increases the number of faces and the SKP file size.
7. Open the exported file in SketchUp. Measure a known dimension, check face orientation and scale, remove duplicated geometry, and reorganize materials, groups, components, and tags as necessary.

For a no-install conversion, use the converter on 101convert.com: select the IGES file, choose SKP when it is offered as the output format, start the conversion, and download the result. Inspect the downloaded model in SketchUp because automated conversion may provide no control over unit interpretation, surface healing, or tessellation; do not upload confidential engineering data unless its handling is acceptable.

SketchUp normally does not provide native IGES import. Autodesk Fusion, FreeCAD, and similar CAD applications can read IGES, but exporting to OBJ, STL, DWG, DXF, or another intermediate format does not by itself create an SKP file. A subsequent application with SKP export is still required, and STL is unsuitable when curved CAD surfaces or editable surface boundaries must be retained.

Quality and compatibility limits

Many IGES files import as disconnected surfaces rather than watertight solids, especially when the sender exported individual faces or the source model contains small gaps. Such geometry may display correctly but can cause problems with SketchUp face orientation, shadows, sectioning, and solid operations.

Exporting to SKP requires tessellation: mathematically smooth IGES surfaces become polygonal SketchUp faces. Increase mesh quality for close-up curved parts, but avoid excessive density, which creates thousands of small faces and slows SketchUp without improving accuracy at the intended viewing scale.

Verify units in both applications. A missing or misread IGES unit declaration can make a millimetre model appear in inches, producing a scale error of 25.4. Measure a known feature in Rhino or the source CAD system and again in SketchUp before using the model for construction, fabrication, or dimensional layout.

IGES generally does not carry SketchUp-specific scenes, components, tags, or native materials. Layer names and basic colors may transfer through some importers, but expect to rebuild the SketchUp organization and reapply materials after conversion.