FreeCAD
The open-source parametric CAD modeller that finally grew up. Since the 1.0 release it is a credible day-to-day tool for mechanical design, not just a hobbyist curiosity.
If you want parametric, history-based mechanical CAD without a subscription or a cloud login, FreeCAD is the answer. The 1.0 release (late 2024) fixed the two things that historically drove people away — the topological-naming problem and the lack of a native assembly workbench — and 1.1 (March 2026) built on that with sketcher and performance refinements. It is now a genuine open-source alternative to Fusion 360 and SolidWorks for most part and small-assembly work.
What it is
FreeCAD is a general-purpose parametric 3D CAD application. You model by sketching constrained 2D profiles and turning them into solids through operations — pad, pocket, revolve, loft — that stay in an editable history. Change a sketch dimension and everything downstream rebuilds. Its geometry kernel is the mature open-source OpenCASCADE, and the whole application is built around a Python core, so anything you can do in the GUI you can also do in a script.
It is organised into workbenches — Part Design for mechanical parts, Sketcher for constrained 2D, Assembly for joining parts, FEM for analysis, Path for CAM, and dozens more from the community. You move between them depending on the job.
Where it wins
- Truly free and offline. No subscription, no seat limits, no cloud dependency, no telemetry. Your models are local files in an open format.
- Parametric and scriptable. The Python core makes FreeCAD ideal for parts that are really configurations — generate a family of brackets from a spreadsheet, or drive geometry from code.
- 1.0 fixed the dealbreakers. The new topological-naming mitigation means edits no longer randomly break references, and the built-in Assembly workbench removed the need for third-party add-ons.
- Integrated downstream. The same app does FEA (via CalculiX) and CAM (Path), so a part can go from sketch to simulation to toolpath without leaving it.
Where it still hurts
- Learning curve. The workbench model and sketcher conventions are unfamiliar if you come from Fusion or SolidWorks. Budget real time.
- Large assemblies. It is happiest with parts and modest assemblies; hundred-part assemblies still feel heavy.
- Surfacing. Complex freeform/organic surfacing is weaker than dedicated tools — reach for Blender or a commercial package there.
The AI angle
FreeCAD's Python API makes it one of the most LLM-friendly CAD tools available: a model can ask an agent to generate a parametric part as a script, run it headless, and inspect the result. Expect "describe the bracket, get a parametric FreeCAD model" workflows to mature quickly — the scriptable core is exactly what code-generating models need. It pairs naturally with code-CAD libraries like build123d for prompt-to-part pipelines.
Start here
- Download from freecad.org — 1.1.1 is the current stable release (April 2026), with a complete CAM library and Assembly refinements.
- Learn the Part Design + Sketcher loop first — it is 80% of mechanical work.
- Source: github.com/FreeCAD/FreeCAD.