Free online IGES to BMP converter

CAD viewers, documentation systems, and some older Windows applications require a bitmap image rather than editable CAD geometry. Converting an IGES model to BMP therefore produces a rendered or projected 2D view for display, annotation, printing, or archiving.

What the IGES format is

IGES (Initial Graphics Exchange Specification) is a text-based CAD exchange format for transferring geometry between engineering applications. An IGES file can contain wireframes, surfaces, solids, curves, annotations, and assembly-related data, although support for individual entity types varies between programs.

Mechanical and industrial CAD systems such as AutoCAD, CATIA, Siemens NX, SolidWorks, Creo, and FreeCAD can create or import IGES files. You typically encounter .igs or .iges files when receiving models from another CAD system, exchanging legacy engineering data, or importing supplier geometry.

What the BMP format is

BMP is a raster image format that stores pixels, commonly with 24-bit color or 32-bit color including an alpha channel. It is supported by Windows software, image editors, documentation tools, and older technical applications without requiring a CAD viewer.

BMP is useful when a fixed 2D representation is sufficient and uncompressed pixel data is preferred for compatibility or simple editing. It does not retain IGES curves, surfaces, dimensions, layers, units, tolerances, or 3D camera information, so the conversion is a visualization rather than a geometry-preserving export.

How to actually convert IGES to BMP

Using the online converter

1. Open the IGES-to-BMP converter on 101convert.com.
2. Upload the .igs or .iges file and choose BMP as the output format.
3. Start the conversion and download the resulting bitmap when processing finishes.

You can convert the file on the 101convert.com website for free without installing any software. This method is suitable when the required result is an automatically generated preview; it may not provide detailed control over camera angle, hidden-line display, resolution, or background.

Using FreeCAD for controlled output

1. Install FreeCAD and open the IGES file with File → Open.
2. Allow the Part or OpenCASCADE importer to load the geometry, then use View → Standard views or the navigation controls to select the required orientation.
3. Use View → Fit all to center the model and adjust the display mode, background, edge visibility, and perspective.
4. Use View → Save image... to save the current viewport, preferably as PNG when available.
5. Convert the saved image to BMP with ImageMagick:

magick model.png -background white -alpha remove -alpha off model.bmp

If the source application can export BMP directly, open the IGES model there, set the view and image dimensions, then choose File → Export or its screenshot/export-image command and select BMP.

Quality and compatibility limits

The BMP contains only the selected view. Use a larger viewport or export resolution for readable edges and annotations; enlarging a small BMP afterward cannot restore detail. Orthographic projection is normally better for technical drawings, while perspective shows depth but changes apparent proportions.

IGES imports can contain unsupported entities, open surfaces, duplicate edges, or incorrect units. Inspect the model before rendering, and use a white background with dark edges when the BMP will be printed or inserted into documentation. Large, uncompressed BMP files can be substantially bigger than PNG files; convert to BMP only when the receiving software specifically requires it.