Free online IGES to IGS converter

Rename .iges to .igs when a CAD system requires the shorter IGES extension.

Convert IGES to IGS online - free

.iges .igs

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How to convert iges to igs file

August 13, 2026
CAD formats
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A customer, PLM system, or older CAD importer may accept .igs but reject .iges. Because both extensions normally identify the same IGES data format, the required change is usually a filename extension change rather than a geometry translation.

What IGES files contain

IGES means Initial Graphics Exchange Specification, a neutral CAD exchange standard developed for transferring design data between otherwise incompatible systems. An IGES file is normally an ASCII text file organized into fixed-length records and can contain 2D drawing entities, wireframes, curves, surfaces, trimmed surfaces, solids, layers, colors, annotations, and associated property data.

IGES is common in supplier exchanges, long-term engineering archives, tooling workflows, and legacy CAD environments. Mechanical designers, manufacturers, aerospace suppliers, mold makers, and engineering teams use it when native CAD files cannot be shared reliably.

What the IGS extension means

IGS is the shorter filename extension for the same IGES standard. Files named part.igs and part.iges normally use identical entity definitions, record structure, and geometry data.

The main advantage of .igs is compatibility with applications, automated import rules, or legacy systems configured to recognize only the three-letter extension. Renaming does not change geometry, units, layers, colors, or file size.

Rename an IGES file to IGS

Keep a copy of the original file, such as part.iges.
Make file extensions visible in the file manager. In Windows File Explorer, select View → Show → File name extensions.
Rename part.iges to part.igs and accept the operating system warning.
Import or open part.igs in the receiving application and verify the model and its units.

On Windows Command Prompt, use ren part.iges part.igs. On macOS or Linux, use mv part.iges part.igs.

If a workflow requires an uploaded output file, convert the file on 101convert.com for free without installing software. For an actual CAD re-export, use a CAD application with IGES import and export support, such as FreeCAD: import the source file, then select File → Export and choose the IGES format. Re-export only when the target system rejects a correctly renamed file or requires cleaned-up geometry.

Compatibility and quality checks

Changing the extension does not repair or translate the model. It cannot fix invalid entities, close surface gaps, create solid topology, alter unit definitions, or reduce the file size. If a renamed file fails to import, the receiving program may have limited IGES support or may reject entities produced by the source CAD system.

IGES transfers geometry well but can be less reliable for complex model semantics than modern exchange formats. Assemblies, feature history, constraints, parametric relationships, materials, PMI, and CAD-specific metadata may be absent, simplified, or imported differently. Many IGES models are delivered as trimmed NURBS surfaces rather than watertight solids.

After importing a file from another CAD system, inspect unit scale, surface gaps, trim boundaries, solid validity, layers, colors, drawing text, dimensions, and annotations. A CAD re-export can change unsupported entities or discard data, so a direct rename is preferable when the recipient only requires the .igs extension.

IGES vs IGS: format comparison

How the IGES and IGS formats compare on the properties that matter most for this conversion.

Comparison of the IGES and IGS file formats
Property	.IGES Initial Graphics Exchange Specification	.IGS Initial Graphics Exchange Specification
Dimensions	3D	3D
Geometry	Both	Both
Layers	—	No
Materials	—	Limited
Plain-text readable	Yes	No
Operating system support	Wide	Wide
Typical file size	Large	Medium
Open standard	Partly open	Partly open
Introduced	1980	—
Developer	IGES/PDES Organization; later maintained through ANSI/ASME standardization	IGES/PDES organization (later managed by various standards bodies, including ANSI/ASME)

Open IGES file Open IGS file

Frequently asked questions

Is the IGES to IGS converter free?

Yes, converting IGES to IGS on 101convert.com is completely free. No registration, email address or installation is required.

How large can my IGES file be?

You can upload IGES files up to 500 MB and convert up to 5 files at once in a single batch.

What happens to my uploaded files?

Files are processed automatically and deleted from our servers within a few minutes after conversion. We never view or share your files.

Do I need to install any software to convert IGES to IGS?

No. The IGES to IGS conversion runs entirely online in your browser and works on Windows, Mac, Linux, Android and iPhone.

Did the conversion fail?

In most cases, the cause is an incorrect file format. Please upload a valid IGES file for this IGES to IGS conversion. Occasionally, the issue may be on our side. We analyze recurring conversion failures and disable or fix the converter if we detect a defect.

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Free online IGES to IGS converter

Convert IGES to IGS online - free