Convert IGES to STEP
Free IGES to STEP converter that runs in your browser. See real dimensions before you download.
How to convert IGES to STEP
- Drop your IGES file onto the converter — it opens in your browser, nothing is uploaded.
- Check the preview and the dimensions in mm; fix units or the up axis in “Units & orientation” if the size or orientation looks wrong.
- Choose STEP as the output and click Convert. Several files download as one ZIP.
What carries over from IGES to STEP
| IGES | STEP | Result | |
|---|---|---|---|
| Colour / materials | No | Yes | — |
| Textures | No | No | — |
| Units stored in file | Yes | Yes | Written as mm |
| Separate parts | Yes | Yes | Kept |
| Usual up axis | Z | Z | Unchanged |
About IGES files
IGES was first published in 1980 by the US National Bureau of Standards, with participation from Boeing, General Electric and others, as one of the earliest standards for moving CAD data between different systems. Files use the .igs or .iges extension and are fixed-width 80-column text records divided into Start, Global, Directory Entry, Parameter Data and Terminate sections, a layout that reflects its punched-card heritage. IGES describes wireframe curves, trimmed and untrimmed NURBS surfaces, and, in later revisions, solids, but in practice it is mostly used for surface data. The format has not been updated since version 5.3 in 1996; STEP replaced it as the preferred standard. Even so, aerospace, automotive and tooling companies keep large IGES archives, and some CAM and surface-modelling programs still ask for it.
About STEP files
STEP, formally ISO 10303 and known as the Standard for the Exchange of Product model data, has been developed since the 1980s and is the main neutral format for moving CAD models between companies and systems. The usual application protocols are AP203 and AP214 for geometry and assemblies, and AP242 for modern product and manufacturing information. A .step or .stp file is plain text written in the EXPRESS-based Part 21 syntax. Unlike STL, it does not store triangles: it stores boundary representation (B-rep) geometry, meaning exact planes, cylinders, splines and NURBS surfaces joined by edges and faces into solids. That keeps holes perfectly round and dimensions precise, and allows the receiving CAD to keep editing faces. Files can contain assemblies, product structure, colours and units.
3D printing notes
IGES is not a printing format, and slicers do not open it. The file must be tessellated to STL or 3MF first, and the surface-only nature of many IGES files creates the main difficulty: if patches are not stitched into a closed shell, the resulting mesh has holes and slicers report it as non-manifold. When that happens, stitch or sew the surfaces in your CAD program, or run a mesh repair afterwards. MeshShift reads IGES and IGS through OpenCascade in the browser, with draft, normal or fine tessellation, and then offers the print check to find open edges and rebuild a closed solid at the same size. It does not write IGES; STEP is the better target for CAD.
Frequently asked questions
Is this IGES to STEP converter free and private?
Yes. The conversion runs in your browser with JavaScript and WebAssembly, so your IGES file is never uploaded to a server. There is no sign-up, no watermark and no daily limit; very large files are limited only by your device's memory.
Is IGES the same as IGS?
Yes. IGS is the three-letter extension used by systems that limited file names, and IGES is the full form. They contain the same data, and software that opens one will open the other, so renaming a .igs to .iges is safe.
What is the difference between STEP and STP?
Nothing in the content. Both extensions hold the same ISO 10303 Part 21 text; .stp exists because older systems limited extensions to three letters. Any program that reads one reads the other, and renaming the file is enough.