Convert IGES or IGS to STL online

Upload your .iges or .igs file to the converter at the top of this page and download one binary STL in millimetres. FreeCAD, which is free, can also open an IGES and export STL. Marathon OS is the paid route if you don't have CAD at hand: first 2 files free, then 1 credit per file.

First 2 files free, any size up to 300 MB. After that, 1 credit per file. Credit packs bring it down to $1.80 per file. Prices include tax, you pay only when you click Download and credits never expire.

Yes. .igs is the short extension for IGES; both convert the same way.

We work to make it watertight: we weld the edges, close small gaps and, on smaller files, mesh a part again finer when it stays open. The quality report says whether each solid came out watertight. An IGES of loose surfaces can leave gaps we can't close.

Binary. It's smaller than ASCII, and every slicer reads it.

Millimetres. STL has no unit field, and most slicers read STL as millimetres, so the part comes in at the right size. We read the unit stored in the IGES, so an inch file comes out at the right size.

Every IGES is meshed at a 1.0 mm chord tolerance and about 29° between neighbouring triangles. On files under 20,000 faces and 200 solids, a part that doesn't come out closed is meshed again finer, down to 0.1 mm. Meshes over 100,000 triangles are reduced to about 100,000, unless that would open the mesh or change its size. There are no quality presets.

Yes, two ways. Export the mesh from your CAD program at a smaller deviation; FreeCAD, which is free, opens IGES files. Or convert IGES to STEP first: our STEP to STL converter meshes at a 0.15 mm chord tolerance. That's two conversions.

It still converts. Trimmed surfaces are meshed and their edges welded, but gaps between surfaces can leave the mesh open. For surface-only files, the quality report marks the solid and watertight checks as not applicable, so check the mesh before you print it.

Every part keeps its assembled position, merged into one mesh without part names.

Yes. Every conversion comes with a free quality report with 12 checks, including whether the mesh is watertight, degenerate triangles, mesh uniformity, a bounding-box match with the IGES and how much of the surface the mesh covers. For a surface-only IGES, the solid and watertight checks are marked not applicable.

Yes. Our STL to IGES conversion rebuilds an IGES file from the mesh. Curved areas may stay faceted, and there's no feature tree. Keep your original IGES if you will need the exact geometry.

IGES files from any CAD program, as .iges or .igs, up to 300 MB. We read both solids (type 186) and trimmed surfaces (type 144). Files that use commas as decimal points, which some SolidWorks setups write, are fixed before reading.

To upload your own file, sign in with Google or an emailed code. The sample file works without signing in.

It depends on the file. Large assemblies can take several minutes, and we email you when the file is ready.

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