Model your parts
Start with a sketch or a primitive. Set dimensions, combine shapes, then add fillets and chamfers.
Explore the tools →NASSCAD 4.7.0 — free CAD for your browser and Windows
Model parts, inspect STEP and IFC assemblies, and prepare designs for 3D printing.
Make something useful
From a first shape
to a part you can use.
Prepare for fabrication
Export STL or 3MF for 3D printing, or SVG and DXF sections for your cutting workflow.
Try a worked example →Import and export STEP
Browse assembly folders, parts and colours. Export AP203, AP214 or AP242; MEDUSA can reuse the source B-Rep of eligible unchanged parts.
STEP workflow →Building models, too.
Inspect IFC geometry in the same workspace. Read the IFC guide →
Inside NASSCAD
See the whole assembly.
Model: Modern Cruise Ship Evita by Christian Spreafico, via the STEP Tools test collection. Third-party model shown for demonstration; no model file is hosted here.
NassScript
Build a scene.
Bring it to life.
Use JavaScript to create parts, repeat operations and animate mechanisms. Write your own script, or ask an AI assistant to help draft one, then review and run it locally.
Explore the engine and its script →Also discover the Solar System demo.
NASSCAD for Windows
One application : Two ways to run it.
Both editions work offline and include MEDUSA, the native geometry engine. No separate engine download is needed.
Windows Setup
Install NASSCAD on your computer, with desktop and Start menu shortcuts.
Download SetupWindows Portable
Download the executable and run it directly. Keep it wherever you prefer.
Download PortableInstallation details · Checksums · License
Updated 5 November: corrected STEP face colours, exact B-Rep volume with MEDUSA, and object controls shown together on one double-click. Read the manual →
Advanced downloads: standalone MEDUSA and source code
MEDUSA for browser users
Optional native processing for the browser edition. Unzip the package and keep its engine and runtime files together. Already using Setup or Portable? You already have MEDUSA.
Download MEDUSA 3.1 · 22 MB ZIP ↓Source code
Explore the code, build the application or contribute. Source is available under AGPL-3.0-only; dependencies retain their own licenses.
A little guidance
Find your next step.
Learn the application
An illustrated manual for modelling, project files, imports and exports. Includes examples and keyboard shortcuts.
Follow a practical guide
For the classroom, the workshop or your next project. Free personal, educational and commercial use under AGPLv3. Your original designs remain yours. Questions or feedback? →