How do I open IGES files online?

Upload .iges, .igs, wait for the browser preview, then zoom, pan, rotate and inspect the model. No desktop CAD installation is required.

Which IGES extensions are supported?

This page accepts .iges, .igs files up to 300 MB.

Can I edit the IGES file in this viewer?

No. The viewer is for inspection. Use a CAD application or design service when geometry, features or dimensions must be changed.

Will an IGES viewer show whether the model is a solid?

It can reveal visible gaps and missing surfaces, but definitive body status should be checked in the receiving CAD system. IGES often contains loosely connected surfaces.

Can I convert IGES to another format?

Yes. IGES to STEP is the most common route when a modern mechanical CAD workflow needs connected B-rep geometry or product structure. Always verify the converted body.

What is the maximum file size?

You can upload one supported file up to 300 MB. Large and complex models may take longer to render.

How are uploaded files handled?

Files are processed privately, are not published to the CAD library and are automatically deleted within 7 days. You retain ownership.

Free online tool

Free Online IGES File Viewer

Open and inspect IGES or IGS surface models online without installing CAD software. Preview curves, wireframes and trimmed surfaces securely in your browser before repair, conversion or manufacturing handoff.

Free online viewer • Private uploads • Up to 300 MB • Auto-delete within 7 days • No CAD software needed

Drag and drop your IGES file here

or click to browse files

Supported input formats: .iges, .igs

No IGES file available? Open a verified sample model.

Need a production-ready native CAD file?

A viewer can inspect geometry but cannot rebuild features, repair missing faces or add manufacturing detail. Work with a vetted designer when the model needs engineering changes.

Hire a CAD designer

What is an IGES file viewer?

An IGES viewer opens legacy Initial Graphics Exchange Specification files for visual inspection. It helps you review curves, wireframes and surface-based models, but it does not automatically sew gaps, repair trims or turn loose surfaces into a solid.

When to use this viewer

Use it to review a legacy supplier file, confirm that an IGES export is complete, inspect a converted model or identify scale and surface problems before moving the geometry into STEP, CAD or CAM.

What to check before using the file

Expected curves, surfaces and visible shape
Known dimensions and unit interpretation
Gaps, open edges and disconnected patches
Reversed faces or failed trim boundaries
Whether the receiving CAD/CAM tool supports the same IGES entities

IGES to STEPmove legacy surfaces into modern CAD exchange STEP to IGEScreate an IGES handoff OBJ to IGESinspect a mesh-derived surface result STEP File Viewerreview a STEP alternative

Need to convert the file?

Use IGES to STEP when a current mechanical CAD system needs STEP, or choose another supported output in the CAD converter. Conversion cannot repair every damaged surface automatically.

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Preview a model, find an existing design, open a technical drawing or get specialist help.

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HOW IT WORKS

How to view IGES files online

No downloads or plugins. Inspect the model directly in a modern browser.

Upload your IGES file

Drag and drop or browse for .iges, .igs. Files up to 300 MB are supported.

Preview in your browser

Rotate, zoom and pan around the geometry. Look for missing patches, loose curves, reversed faces and gaps between trimmed surfaces.

Decide the next action

Convert clean geometry when another format is required. If the model has open edges or missing surfaces, repair the source before relying on the conversion.

Upload IGES file Open the CAD converter

What you can inspect in IGES

Visible curves, wireframes and trimmed surfaces
Overall orientation and model extents
Missing or disconnected surface patches
Open boundaries and unexpected gaps
Whether legacy geometry is suitable for conversion

What this viewer does not do

Sew loose surfaces into a guaranteed solid
Repair invalid trim loops or missing faces
Recover native feature history or constraints
Guarantee support for every legacy IGES entity
Validate manufacturing tolerances or toolpaths

Why use Marathon OS CAD Viewer

Open a file quickly without installing a large desktop application, then decide whether it is ready to share, convert or repair.

Instant preview

Open and inspect supported geometry in the browser.

Surface-focused review

Inspect legacy IGES/IGS geometry for gaps, missing faces and surface orientation before conversion or CAD/CAM use.

Faster review

Use the same browser-based inspection step before conversion, quoting or supplier handoff.

Anywhere access

Use a modern browser on desktop, tablet or mobile; complex files are easiest to inspect on a larger screen.

BEFORE THE NEXT WORKFLOW

Checks to make before using a IGES file

A model that opens can still contain scale, topology or completeness problems. Record these checks before manufacturing or conversion.

01
Verify units and dimensions
IGES may carry units, but exporters and importers can interpret settings differently. Measure a known feature.
02
Inspect all expected entities
Confirm that surfaces, curves and wireframes exported by the source system are visible.
03
Find open edges and gaps
Look for surface boundaries that do not meet or patches that are missing.
04
Review trims and orientation
Check reversed faces, invalid trim loops and unexpected holes.
05
Determine body status downstream
An IGES may display as a complete shape but still import as loose surfaces rather than a solid.
06
Test the target application
Open the file in the exact CAD/CAM tool used next and compare the result.

COMMON PROBLEMS

IGES viewer troubleshooting

IGES problems are commonly caused by legacy entity support, loose tolerances, invalid trims, missing surfaces or inconsistent unit interpretation.

The model has holes or gaps

Cause: Surface boundaries do not meet or a patch is missing.

Fix: Heal/sew surfaces in CAD or request a repaired export.

Some curves or faces do not appear

Cause: The file uses unsupported or invalid IGES entities.

Fix: Re-export using broadly supported curve and trimmed-surface types.

The model is the wrong size

Cause: The file unit or receiving application setting was interpreted differently.

Fix: Measure a known feature and apply the intended unit.

Faces look reversed or dark

Cause: Surface orientation or trim direction is inconsistent.

Fix: Repair normals/orientation in a CAD system before downstream use.

The file opens as loose surfaces

Cause: IGES does not guarantee connected solid topology.

Fix: Convert to STEP and heal the result, or repair the IGES surfaces first.

A complex file is slow

Cause: Many patches, curves and legacy entities increase processing and rendering time.

Fix: Export only required geometry or simplify unnecessary detail.

Privacy and file handling

Product models can contain confidential engineering information. Keep file handling clear beside the upload action and in the FAQ.

Private uploads

Files are processed privately and are not added to the public CAD library.

Automatic deletion

Uploaded files are automatically deleted within 7 days.

You retain ownership

Viewing a file does not transfer ownership of the design to Marathon OS.

Who the IGES viewer is for

Engineers reviewing legacy supplier geometry

CAD/CAM teams checking surfaces before import

Manufacturing teams validating an exchange file

Designers inspecting a conversion result

Users without the original authoring software

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Browse the Marathon OS library for a potential starting point. Review dimensions, licensing and production suitability before use.

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Frequently asked questions about the IGES viewer

Answers about supported files, inspection limits, conversion, file size and privacy.

How do I open IGES files online?
Upload .iges, .igs, wait for the browser preview, then zoom, pan, rotate and inspect the model. No desktop CAD installation is required.
Which IGES extensions are supported?
This page accepts .iges, .igs files up to 300 MB.
Can I edit the IGES file in this viewer?
No. The viewer is for inspection. Use a CAD application or design service when geometry, features or dimensions must be changed.
Will an IGES viewer show whether the model is a solid?
It can reveal visible gaps and missing surfaces, but definitive body status should be checked in the receiving CAD system. IGES often contains loosely connected surfaces.
Can I convert IGES to another format?
Yes. IGES to STEP is the most common route when a modern mechanical CAD workflow needs connected B-rep geometry or product structure. Always verify the converted body.
Open CAD converter
What is the maximum file size?
You can upload one supported file up to 300 MB. Large and complex models may take longer to render.
How are uploaded files handled?
Files are processed privately, are not published to the CAD library and are automatically deleted within 7 days. You retain ownership.

Open your IGES file online

Upload .iges or .igs to inspect legacy surface geometry before repair, conversion, quoting or CAD/CAM use.