# IGES Viewer

> Open IGES (.iges, .igs) CAD files in your browser with OpenCascade: surfaces and solids from older CAD and CAM systems, in millimetres.

Page: https://printpal.io/tools/iges-viewer
Updated: 2026-11-12
Use it: open https://printpal.io/tools/iges-viewer in a browser and drop a file. Free, no account, files are processed locally and never uploaded.

IGES was first published in 1980 and is still the lowest common denominator between CAD and CAM systems. It often carries trimmed surfaces rather than closed solids, so a model can look solid but have gaps between its faces.

The viewer meshes every surface with OpenCascade (the reader downloads once, about 7 MB). The mesh check then shows whether the surfaces close into a solid; if they don't, sew them in CAD or repair the mesh before printing.

## How to use the IGES viewer

1. **Open the file.** Drop .iges or .igs files. The CAD reader (about 7 MB) downloads the first time.
2. **Check size and orientation.** The model stands on the plate in millimetres. Switch to inches, or change the file units or up axis if it looks wrong.
3. **Run the checks.** Read the mesh check, pick your printer to see whether it fits, and use Measure (M) or Section (X) for a closer look.
4. **Save or convert.** Take a PNG screenshot, or save the model as STL, 3MF, OBJ, GLB, PLY or USDZ.

## What you can check

- Trimmed surfaces and solids, meshed at Draft, Normal or Fine quality
- Size in mm or inches from the declared unit
- Open-edge count showing gaps between surfaces
- Section view and measuring
- Save as STL, 3MF, OBJ or GLB

## IGES at a glance (Initial Graphics Exchange Specification)

IGES was first published in 1980 and is still the lowest common denominator between CAD and CAM systems. It often carries loose surfaces rather than closed solids.

- **Stores:** Curves and trimmed surfaces, sometimes solids
- **Color:** Per entity, rarely used
- **Units:** Declared in the file
- **Up axis:** Usually Z
- **Meshing:** Needs tessellation; surface models may not close into solids
- **Opens in:** Most CAD and CAM systems

## Tips

- **Gaps between faces?** That is normal for surface IGES. Sew the surfaces into a solid in your CAD tool, or try [Mesh Repair](https://printpal.io/tools/mesh-repair) on the STL.
- **Prefer STEP** If you can choose the export, STEP keeps solids and colors far more reliably than IGES. The [STEP viewer](https://printpal.io/tools/step-viewer) opens both.
- **Small features** Switch the CAD quality to Fine for small holes and fillets.

## FAQ

### What is the difference between IGES and IGS?

Nothing: .iges and .igs are two extensions for the same format.

### Why does my IGES model have holes?

IGES often stores separate surfaces that only appear to meet. When meshed, the seams become open edges. Sewing the surfaces in CAD fixes it at the source.

### Can I convert IGES to STL?

Yes, with [IGES to STL](https://printpal.io/convert/iges-to-stl) or the Save as STL button here.

### Is the viewer free? Are there limits?

Free, with no sign-up, watermark or file limit. The practical limit is your device's memory: files of a few hundred MB open on most laptops.

### Are my files uploaded anywhere?

No. Files are read by JavaScript and WebAssembly in your browser and never sent to PrintPal. Only the code is downloaded, and the STEP and IGES reader once, from a public CDN.

## Related

- [IGES to STL Converter](https://printpal.io/convert/iges-to-stl)
- [STL to OBJ Converter](https://printpal.io/convert/stl-to-obj)
- [OBJ to STL Converter](https://printpal.io/convert/obj-to-stl)
- [STEP to STL Converter](https://printpal.io/convert/step-to-stl)
- [STL to 3MF Converter](https://printpal.io/convert/stl-to-3mf)
- [GLB to STL Converter](https://printpal.io/convert/glb-to-stl)
- [STL Viewer](https://printpal.io/tools/stl-viewer)
- [3D model viewer](https://printpal.io/tools/3d-model-viewer)
- [3D model converter](https://printpal.io/tools/3d-model-converter)
- [Mesh Repair](https://printpal.io/tools/mesh-repair)
- PrintPal for LLMs: https://printpal.io/llms.txt