Free online IGS to STL converter
Convert IGES CAD geometry to STL mesh files for slicing, printing, and mesh inspection.
Convert IGS to STL online - free
Your file is processed instantly and deleted as soon as you download it.
Import a file from a URL
Paste a direct link to the file. We download it to our server and it is converted exactly like an upload.
How it works
-
1/3
Upload your .igs file
Click to browse to select your file you want to convert or simply drag & drop your file into selected area.
-
2/3
Perform .igs to .stl conversion
After successful file upload, click to convert when you are ready.
-
3/3
Download converted .stl file
Conversion result is ready to download.
How to convert igs to stl file
- CAD formats
- No ratings yet.
A CAD model received as an .igs file must be converted when a slicer, mesh repair program, or printer workflow requires STL input. The conversion replaces CAD surfaces with triangles that can be sliced for additive manufacturing.
What IGS files contain
IGS and IGES refer to the Initial Graphics Exchange Specification, a neutral CAD exchange format commonly saved as .igs or .iges. It can contain curves, NURBS and trimmed surfaces, boundary-representation solids, layers, colors, and drawing annotations.
IGES is widely encountered in supplier, manufacturing, and legacy-CAD exchanges when the original native model is unavailable. Applications such as CATIA, Siemens NX, SOLIDWORKS, Autodesk Fusion, Rhino, and FreeCAD can import it, although support for specific IGES entities varies.
An IGS file may define a complete solid, a collection of surfaces, or unrelated geometry. Surface-only imports often need stitching, healing, or capping before they can become printable shells.
What STL files contain
STL stores only a triangulated surface: each facet is defined by three vertices and a normal direction. It does not preserve CAD features, editable sketches, dimensions, assemblies, material assignments, or parametric surface definitions.
STL is accepted by most 3D-printing slicers and supported by mesh inspection and repair software. Binary STL normally produces a smaller file than ASCII STL while representing the same geometry.
Standard STL has no unit field. A model exported in millimeters can be interpreted as inches, or the reverse, by another program. Verify the dimensions in the slicer before printing.
Convert an IGS model to STL
Upload the .igs or .iges file to the converter on 101convert.com, select STL as the output format, convert it, and download the mesh. Open the resulting STL in the intended slicer or mesh viewer to check its size, orientation, and surface quality.
For local conversion in FreeCAD:
- Open the IGS file using File → Open.
- Inspect the imported objects. If the model consists of multiple faces or bodies, select the geometry intended for one exported mesh.
- Switch to the Mesh Design workbench and choose Meshes → Create mesh from shape.
- Set the mesh deviation or chordal-deflection value. Lower values follow curved surfaces more closely but create more triangles.
- Select the generated mesh and use File → Export to save
model.stl.
In Autodesk Fusion, upload or open the IGS model, select the required body or component in the Browser, then use the context-menu command Save as Mesh. Choose STL and set the refinement or tolerance before saving. In Rhino, use File → Import, select the object, then choose File → Export Selected and select STL; Rhino displays mesh settings before export.
Mesh quality and printability
Conversion to STL is lossy. Smooth curves, fillets, holes, text, and threads become planar facets; converting the STL back to editable CAD geometry requires reverse engineering or surface fitting.
A coarse mesh creates visibly faceted curves and can alter dimensions. An excessively fine mesh produces large files, slow slicing, and potentially millions of triangles without improving printer resolution. Set chordal tolerance below the dimensional error acceptable for the part, then inspect curved edges and small details.
For reliable slicing, each printable part should normally be a closed, non-self-intersecting shell with consistently oriented normals. Check for holes, open edges, duplicate surfaces, inverted normals, zero-thickness regions, and separate overlapping bodies. FreeCAD, Blender, and many slicers provide mesh-analysis or repair functions, but repairing the original CAD surfaces is preferable when possible.
IGES includes a declared unit setting, but importers can misread or override it. If a nominal 25.4 mm part appears 25.4 times too large or small after export, correct the scale before generating printer toolpaths.
IGS vs STL: format comparison
How the IGS and STL formats compare on the properties that matter most for this conversion.
| Property | .IGS Initial Graphics Exchange Specification | .STL Stereolithography |
|---|---|---|
| Open standard | Partly open | Partly open |
| Compression | Uncompressed | Uncompressed |
| Typical file size | Medium | Small |
| Opens in a web browser | No | No |
| Further editing | Limited | Not directly editable |
| Metadata support | Basic | None |
| Plain-text readable | No | Yes |
| Best used for | Data exchange | Embedding in applications |
| Introduced | — | 1987 |
| Developer | IGES/PDES organization (later managed by various standards bodies, including ANSI/ASME) | 3D Systems |
| MIME type | — | model/stl |
Suggested software and links: igs to stl converters
Frequently asked questions
Is the IGS to STL converter free?
Yes, converting IGS to STL on 101convert.com is completely free. No registration, email address or installation is required. If you need a higher file size limit or want to convert more files at once, see our plans.
How large can my IGS file be?
You can upload IGS 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 IGS to STL?
No. The IGS to STL 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 IGS file for this IGS to STL 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.
Will converting IGES to STL make my CAD model editable?
No, the conversion turns the IGES geometry into a triangulated surface mesh, so the original curves, surfaces, and parametric design information are not preserved. The STL can be inspected and prepared for printing, but it is not easily edited like the source CAD model.
What happens to the IGES model's accuracy when it is converted to STL?
The result's accuracy depends on the tessellation or mesh-resolution settings used during conversion. A coarse mesh can show faceted curves and inaccurate edges, while a finer mesh follows the IGES surfaces more closely but usually produces a larger STL.
Why does my converted STL have holes or fail in a slicer?
This usually happens when the source IGES surfaces do not form a closed solid, when gaps or overlapping faces are present, or when the mesh has incorrect triangle normals. STL represents triangles rather than a full CAD solid, so those problems may need mesh repair before slicing or printing.
Does STL keep the colors, layers, units, and other IGES information?
No, standard STL generally keeps only the triangle geometry and does not preserve IGES layers, colors, materials, annotations, or parametric metadata. Units can also be ambiguous because STL files do not reliably store a measurement unit, so the model may need to be scaled correctly when it is opened.
Additional formats for
igs file conversion
- igs to model
- igs to stp
- igs to ifc
- igs to dwg
- igs to dxf
- igs to x_t
- igs to catpart
- igs to nc1
- igs to asm
- igs to par
- igs to 3mf
- igs to ad_prt
- igs to ai
- igs to amf
- igs to asat
- igs to brep
- igs to catdrawing
- igs to catproduct
- igs to cgr
- igs to dft
- igs to dgn
- igs to dwt
- igs to edrw
- igs to eprt
- igs to fcstd
- igs to gltf
- igs to iam
- igs to iges
- igs to ipt
- igs to jt
- igs to obj
- igs to ply
- igs to slddrw
- igs to step
- igs to svg
- igs to vda
- igs to x_b