FreeCAD is an open-source 3D CAD program for designing physical objects on Windows, macOS and Linux. It builds models from editable geometry and parameters, allowing a design to develop through changes to its dimensions and construction history. The same project can provide solid geometry, assembled components and two-dimensional drawings for manufacturing or design communication.
Sketch geometry
FreeCAD’s Sketcher creates constrained two-dimensional shapes that become the basis of three-dimensional objects. Constraints express relationships within the geometry, and an integrated solver works out the resulting shape.
These sketches feed the Part Design workbench and other modeling tools. A profile therefore has a role beyond the initial drawing: changing its defining geometry can change the object built from it. FreeCAD uses real-world units, including metric and imperial measurements, so dimensions describe the intended physical object.
Model history
A FreeCAD model retains the parameters behind its construction. Object properties can hold numerical values, text, on/off choices or references to other objects. Returning to the model history lets the user change these values and recalculate the affected shapes, rather than starting the design again.
Properties can also depend on properties elsewhere in the project. One dimension can drive another object’s value, establishing a relationship between parts of the design. Undo and redo track modeling changes while the parameter relationships remain part of the design’s structure.
Solid geometry
FreeCAD works with solid models and precise boundary geometry. Its geometry engine supports NURBS curves and surfaces as well as solids, giving it tools for both enclosed objects and curved forms.
Boolean operations combine shapes, remove one shape from another or retain their overlapping volume. Fillets round selected edges, while shape-cleaning tools address the geometry produced during construction.
Assemblies
The built-in Assembly workbench brings separate components together and defines three-dimensional constraints between them. The assembly consequently records relationships between parts, rather than only displaying several independent models in the same view.
FreeCAD can animate an assembly to show the components moving together. Community assembly workbenches provide additional approaches, with their own solvers and workflows; they are separate options alongside the built-in workbench.
Drawing outputs
A three-dimensional model can supply views and design details for two-dimensional drawings. FreeCAD also provides tools to extract quantities and bills of materials from model data.
CAD Exchange
For exchange with other CAD and production software, FreeCAD supports formats including STEP, IGES, STL, OBJ, DXF, SVG and IFC. These cover different kinds of geometry and drawing data: the output format is selected for the next task, such as transferring a solid model or supplying mesh geometry for a 3D-printing workflow. FreeCAD’s own project format is FCStd, and additional workbenches can add further file-format support.
Extending FreeCAD with Python and workbenches
The integrated Python console provides a way to control FreeCAD through commands. Macro recording captures actions for reuse, while Python programming extends that approach to custom tools and complete workbenches.
Workbenches organize tools around particular kinds of design work. Users can add community workbenches and macros through FreeCAD’s management tools, extending the modeling environment beyond its built-in toolsets.
