Free online IGS to PDF converter

A supplier may deliver an IGES model while a reviewer, printer, approval system, or archive accepts only PDF. Converting it creates a view or drawing that can be shared without CAD software, but normally removes the model’s editable CAD structure.

What the IGS format is

IGS and IGES are filename extensions for the Initial Graphics Exchange Specification, a neutral CAD interchange format. IGES files are commonly ASCII text and can contain wireframe entities, curves, surfaces, solid-related entities, colors, annotations, and drawing data.

Mechanical, tooling, sheet-metal, aerospace, and other engineering workflows use IGES to exchange geometry between different CAD systems. Programs such as SolidWorks, Autodesk Inventor, CATIA, Siemens NX, Creo, Rhino, FreeCAD, and older CAD applications can import or export it. An IGS file contains structured CAD data, not a picture; renaming .igs to .pdf does not convert the file.

What the PDF format is

PDF is a page-based document format that preserves printable layout, vector lines, text, dimensions, annotations, and raster images. It is suitable for design reviews, quotations, approvals, printed drawings, and document archives because recipients generally do not need a CAD application to open it.

A conventional CAD-to-PDF export produces one or more static pages containing projected views such as front, top, side, isometric, or section views. It does not retain the feature tree, parametric constraints, associative dimensions, assembly relationships, editable surfaces, or normal CAD selection and measurement behavior. Some CAD programs can create a 3D PDF with an embedded interactive model, usually based on a format such as PRC or U3D; compatible PDF software is required, and many browser viewers show only the page layer.

Convert an IGS file with 101convert

For a quick visual conversion without installing software, use the IGS-to-PDF converter on 101convert.com for free:

1. Open the IGS-to-PDF conversion page on 101convert.com.
2. Select an .igs or .iges file.
3. Start the conversion and download the generated PDF when processing finishes.
4. Check the model orientation, visible geometry, scale, page margins, and legibility before sharing the file.

This route is appropriate for a reference view or simple presentation. Use a desktop CAD application when the result must have a controlled sheet size, projection layout, dimensions, tolerances, section views, or revision information. Do not upload confidential, export-controlled, or otherwise restricted geometry unless your organization permits that processing method.

Create a controlled drawing with FreeCAD

FreeCAD can import IGES and use its TechDraw workbench to create a drawing page instead of exporting an uncontrolled screenshot.

1. Open the file with File → Open. Select the .igs or .iges file and use an all-files filter if it is not listed.
2. Inspect the imported objects in the 3D view. An IGES import may contain several surfaces, solids, or separate geometric objects.
3. Open the TechDraw workbench and create a page with TechDraw → Insert Page using Template. Choose the paper size and orientation.
4. Select the required imported object or objects and choose TechDraw → Insert View. Set the projection direction, scale, rotation, hidden-line display, and visibility in the view properties.
5. Insert front, top, side, isometric, or section views as needed, then arrange them within the printable area.
6. Add dimensions, tolerances, notes, units, labels, and revision information manually. Imported geometry does not automatically become a complete manufacturing drawing.
7. Select the TechDraw page and use its PDF export command, or use File → Export and choose PDF when supported by the installed FreeCAD version. Save the result as a file such as part_drawing.pdf.

A screenshot or direct print of the 3D view is faster, but it normally produces a rasterized page with no drawing structure and can become pixelated when enlarged. A TechDraw page can preserve vector linework and controlled page layout.

Use a commercial CAD application

In SolidWorks, Autodesk Inventor, CATIA, Creo, Rhino, or another CAD system, open the IGES file, repair or orient the imported geometry, create a drawing or layout, place the required views, and use the application’s PDF export or PDF printer. Menu names and available 3D-PDF features depend on the product, edition, and installed modules. Set paper size, projection, scale, line weights, hidden-line behavior, and image resolution before exporting.

Quality and compatibility limits

• IGES often transfers trimmed surfaces rather than a single watertight solid. Gaps, missing faces, fragmented surfaces, incorrect colors, and failed imports may require sewing or repair before a reliable view can be created.
• Verify units and overall dimensions after import. IGES includes unit information, but missing, incorrect, or misinterpreted metadata can produce inch-to-millimeter or millimeter-to-inch scale errors.
• A visually correct PDF does not prove that the source geometry is suitable for editing, simulation, or manufacturing. Check the model in a CAD application when geometric accuracy matters.
• PDF output records the chosen view or drawing page. It does not preserve native features, constraints, feature history, or dependable downstream editability.
• Hidden lines, edge display, section hatching, shading, tessellation, and line weights depend on the exporting application and its settings. Inspect the PDF at its intended print size and verify orientation, units, clipping, text, and margins.
• Large assemblies and dense shaded views can create slow imports or oversized PDFs. Hide unneeded components and export only the views required for review.
• Keep the original .igs or .iges file. If the recipient needs continued CAD editing, feature history, or precise model interrogation, provide the native CAD file or a suitable solid-exchange format such as STEP instead of relying on PDF.