Free online FCSTD to GLB converter

What the FCSTD format is

.FCStd is FreeCAD's native document format. FreeCAD creates it when you save a parametric CAD project containing bodies, sketches, constraints, feature history, assemblies, spreadsheets, and other document objects. FCStd files are commonly encountered when receiving engineering models from FreeCAD users or when archiving editable FreeCAD work.

An FCStd document is not a single display mesh: it can contain editable solids and construction data. Its feature history, constraints, and most CAD-specific metadata cannot be represented directly in GLB.

What the GLB format is

.glb is the binary form of glTF 2.0. It packages a 3D mesh, materials, textures, and scene information into one file, making it suitable for browsers, WebGL viewers, game engines, AR tools, and many general-purpose 3D applications.

GLB is compact and easier to distribute than a glTF file with separate binary and image assets. It represents the visible result as tessellated polygon geometry rather than as editable parametric CAD features.

How to convert FCSTD to GLB

Using FreeCAD

1. Open model.FCStd in FreeCAD.
2. Recompute the document with Edit → Refresh or the document recompute command, then confirm that the intended bodies and parts are visible.
3. Hide construction geometry, sketches, duplicate feature results, and objects that should not appear in the exported scene. For an assembly, keep the final visible components selected or visible according to the exporter behavior in your FreeCAD version.
4. Select the final solids or bodies in the tree and choose File → Export.
5. Choose the glTF 2.0 binary or GLB format and save the result as model.glb.
6. Open the GLB in a viewer such as Blender or a browser-based glTF viewer and check scale, orientation, colors, and missing parts.

The exact GLB entry depends on the FreeCAD release and installed workbenches. If the export dialog does not offer GLB, update FreeCAD or use the fallback workflow below.

Fallback through Blender

1. In FreeCAD, export the selected final geometry as model.obj using File → Export. OBJ generally preserves polygon geometry and basic material colors, but not parametric features.
2. In Blender, choose File → Import → Wavefront (.obj) and open model.obj.
3. Check the imported object hierarchy, normals, units, and materials. Apply transforms if the model has an incorrect scale or orientation.
4. Choose File → Export → glTF 2.0, set the format to GLB, enable selected-object export if needed, and save model.glb.

You can also convert the file on 101convert.com for free without installing software. Use this option only when the service accepts the FCStd version and the project does not contain confidential design data.

Quality and compatibility limitations

CAD solids must be tessellated before GLB export. Tessellation settings control the balance between curved-surface accuracy and file size: coarse settings create visibly faceted cylinders and fillets, while fine settings increase polygon count and viewing performance costs.

GLB does not preserve FreeCAD sketches, constraints, feature trees, spreadsheets, or editable solid history. Keep the original .FCStd file when future CAD editing is required.

Check units after export because glTF does not enforce a universal scene-unit convention. Also verify face normals and transparency: reversed normals can make surfaces appear invisible, and CAD materials or advanced appearances may be simplified during export. Textures must be embedded or included according to the exporter settings; a binary GLB normally stores them inside the same file.