IGES File Viewer

IGES is the older neutral CAD format, from the 1980s, and it is still everywhere: tooling shops, moulds, aerospace and automotive archives, and older CNC and CAM systems all exchange .igs files. Unlike STEP, IGES often carries surfaces rather than closed solids, and many free viewers either refuse it or show a jumble of patches. This page reads IGES with Open CASCADE, the same kernel FreeCAD uses, and stitches each face into a mesh you can turn around.

Surface models show their trimmed surfaces with black boundary lines. If the faces close up into a solid, the volume is shown; if they do not, the panel says it is not a closed solid, which itself is a quick check before you send a file to a machinist or a 3D printer. Sizes are in millimetres, converted from the units in the IGES header, so an inch file still reads correctly.

Typical jobs: a toolmaker checks an old mould insert before quoting a repair, a buyer confirms a supplier sent the right revision of a bracket, a student opens a part from a 2000s archive that only exists as IGES, or a CNC programmer checks the stock size before loading the file into CAM. In each case the question is simple, what is this part and how big is it, and opening a full CAD program to answer it wastes ten minutes. Here the model appears in a few seconds, in the same orientation the designer used, with Front, Top, Right and Isometric buttons to match the views on the drawing.

The engine runs in a background worker, so the page stays responsive while large files are read, and it is cached after the first visit. It works on phones too: one finger rotates and two fingers zoom and pan, which is handy when a file arrives by email on site and you just need to see it.

When you need a picture for a quote or a report, Save view as PNG captures exactly what is on screen. Download STL is there for 3D printing, but an STL made from open surfaces will not be watertight, so check the volume line first.

The IGES file is read and drawn in this tab. Nothing is uploaded, there is no account, and the file is gone when you close the page.

IGES wireframe-only files (curves and points with no surfaces) have nothing to shade, so they show a message instead of a model. Colours and layers from IGES are not all kept.