Updated October 2, 2026. This article originally introduced NASSCAD 4.2.7. It now describes the current 4.7.0 release and its browser/native engine architecture.
NASSCAD is a parametric 3D CAD application that processes your models locally. Open it in your browser, create solids, sketch in 2D, combine shapes, exchange STEP and IFC files, and prepare models for 3D printing. No application account or cloud processing backend is required.
Try NASSCAD · Source code · Downloads · Report an issue
From the single-file classic to 4.7.0
The original 4.2.7 classic was a self-contained HTML application with its dependencies embedded. It remains available as a historical release.
4.7.0 keeps one HTML entry point, with bundled JavaScript and WebAssembly files beside it. Keep those files together when using the offline package. It would be misleading to describe the current GitHub checkout as one completely self-contained HTML file.
The new release adds OpenCASCADE B-Rep workflows, STEP and IFC support, and MEDUSA: a native companion engine running on your own machine.
Boolean operations: browser first, native when available
Union, subtraction and intersection work without installing MEDUSA. NASSCAD loads the bundled Manifold WASM engine on the first boolean operation and runs it in a browser worker.
When MEDUSA is running, NASSCAD uses native Manifold C++ with TBB for multi-core processing. The CSG panel identifies the engine in use: Manifold WASM or Manifold C++ · MEDUSA.
MEDUSA is useful for large boolean operations and large STEP assemblies. Exact B-Rep STEP export requires MEDUSA. Browser STEP import remains available without it, with limitations on large assemblies and per-face colors.
There is no universal speed multiplier: geometry, resolution, CPU, preparation and transfer costs all matter. The repository includes NASSCAD_bench_perf.js to compare both engines on the same machine, recording engine time and total operation time separately.
STEP, IFC and real CAD operations
- STEP AP203 / AP214 / AP242: assembly import, with native MEDUSA processing for large models and exact B-Rep export.
- PMI and GD&T: support for product manufacturing information in STEP workflows.
- IFC: open IFC2X3, IFC4 and IFC4X3 building models; write IFC4 with a Project / Site / Building / Storey structure.
- Fillets and chamfers: OpenCASCADE B-Rep operations, rather than a visual mesh approximation.
- Mesh workflows: STL, OBJ, 3MF, GLB and PLY, plus SVG and DXF sections.
Modern Cruise Ship Evita by Christian Spreafico, shown to demonstrate STEP assembly import.
Scania V8 XT Turbo Engine by Ivo Jardim. These third-party models remain the property of their authors; model files are not bundled with NASSCAD. See the model credits on the website.
Modeling tools
NASSCAD includes 18 watertight primitives and parametric generators, including gears, screws, nuts, pipes, torii and solids of revolution. Screw and nut generators support metric and imperial workflows, with editable parameters and live previews.
A non-destructive CSG tree records boolean construction steps for editing and re-running. Other tools include 2D sketching, measurements, X-Ray mode, undo/redo, scene management, and printer build volumes for 28 printer models.
NassScript provides a JavaScript console with access to NASSCAD's internal functions. It supports procedural modeling and automation using async / await. The documentation includes examples you can run in the application.
How to try it
- Online: open nasscad.com and launch NASSCAD.
- Offline: download the package linked on the website and keep its files together. Once the components are available locally, model processing can run offline.
-
For developers: clone Nx-Nass/NassCAD, serve the folder over local HTTP, and open
NASSCAD_V4_7_0.htm. The checkout includes roughly 154 MB of OpenCASCADE WASM and data files. - Optional native engine: use the MEDUSA download on the website, or build it from the platform bundles and readable C++ source in the repository. The repository provides Windows/MSVC, Ubuntu and WSL build bundles.
A modern WebGL/WebAssembly-capable browser is required. A desktop-sized screen is recommended for the full modeling interface.
License and project
NASSCAD is a personal project by Nasser / NassLab, developed with AI-assisted coding, including Claude Sonnet 4.6 from Anthropic.
NassLab's code is available under CC BY-NC 4.0, with an additional education permission covering schools, teachers, students and the educational uses described in the license. Commercial use requires an agreement with NassLab. Bundled third-party components retain their own licenses; source availability does not make the project an unrestricted open-source offering.
See the project license and third-party notices for the exact terms.
The GitHub repository now keeps the classic and current histories together, with versions identified through tags and releases. Feedback, reproducible bug reports and practical CAD use cases are welcome.
Try NASSCAD — and tell me what you build.
Top comments (2)
Waiting comments ...
I AM THRAGG