NassLab · Browser-Based CAD · v4.3.0 · Single HTML File

3D Parametric CAD

Open the page. Model your part. Export for your slicer.
Boolean engine · Advanced generators · Full scripting —
all in a single HTML file.

Launch NASSCAD → Download Offline Package Download AIO HTML See what it does
Claude Sonnet 4.6 — Anthropic
AI-assisted coding Claude Sonnet 4.6 · Anthropic
Offline use Native Windows desktop app — installer (setup) or portable (no install), no browser needed.
Single HTML file Unzip, double-click, done — runs best in Chrome (full WASM + GeometryPool speed). No server, no account, fully offline.
Free No install No account Offline-ready STL · OBJ · 3MF · GLB · PLY Manifold WASM CSG Tree NassScript WebGL
NASSCAD racing past TinkerCAD and Autodesk — parametric 3D CAD, zero install

NASSCAD v4.3.0 · NassLab · France

// What is NASSCAD

A real CAD tool.
In your browser.

01

A real CAD tool in your browser

A full 3D parametric CAD application delivered as a single HTML file. No server, no account, no installation. Runs entirely in your browser via WebGL and WebAssembly — online or offline.

02

Built for makers and engineers

Designed for people who actually build things — FDM printing, CNC, mechanical assembly. Every primitive, every export format, every workflow decision was made to get from idea to slicer fast.

03

Scriptable from the ground up

NassScript exposes every internal function via an integrated JS console. Automate complex geometries, create procedural parts, chain boolean operations — all in the same window as your model.

// Editions

Two tiers.
One vision.

From open-source freedom to the pinnacle of analytical CAD power.

STANDARD
Free
Online · Offline · Single HTML File · Manifold WASM Engine
  • 18 primitives paramétriques watertight
  • Boolean CSG — Union · Soustraction · Intersection
  • Screw.Gen · Nut.Gen · Gear.Gen · Lathe.Gen…
  • NassScript — console JS intégrée full-access
  • 200 objets CSG en ~2.6s · Manifold WASM
  • 100% offline · Zéro serveur · Zéro compte
Launch NASSCAD Standard →
⬡ MEDUSA PROJECT
In development
Development underway.
  • Everything in NASSCAD Standard +
  • Embedded OpenCASCADE OCCT kernel Exact analytical geometry · Native B-Rep · Fusion 360 · FreeCAD · CATIA · OpenCASCADE
  • Parametric construction tree Replayable operation history · Non-destructive edits
  • Embedded AI Natural language-assisted modeling
  • ⬡ Additional capabilities undisclosed
// Core Features

Everything you need.
Nothing you don't.

Parametric modeling, boolean operations, advanced generators, memory management — inside a single file you can save to your desktop.

F-01

Boolean CSG — Manifold WASM

Union, subtraction, intersection — powered by Manifold, the open-source C++ CSG kernel developed at Google. Compiled to WebAssembly, runs in a Web Worker. Every boolean is logged in a re-runnable CSG tree.

F-02

Advanced Parametric Generators

ISO involute gears & V-groove pulleys (Gear.Gen), hollow curved pipes with Bishop-frame path (Pipe.Gen), parametric screws ISO 68-1 / UNC·UNF (Screw.Gen), parametric nuts ISO 4032/4033 · ASME B18.2.2 (Nut.Gen), ultra-HD torii, chamfered/rounded cubes, solids of revolution, spherical sectors, threaded fasteners.

F-03

Geometry Pool with GC

A 2 GB ArrayBuffer with a custom mark-and-sweep garbage collector handles all geometry and scene snapshots. BVH/AABB caching on every mesh keeps raycasting fast on complex scenes.

F-04

Full Scene Management

Solid/Hole mode per object for automatic boolean detection. Box-select for bulk ops. Live XYZ transform. Dimension annotations in 3D viewport. Project save/load as JSON.

F-05

Export Quality Control

STL export uses 128 segments by default — optimized for FDM. Quality slider goes higher for SLA or CNC. Hard-dimensions approach: what you model is what you export, 1:1, no scale surprises.

F-06

Import STL · OBJ · 3MF · GLB · PLY

File picker or drag-and-drop import. Imported meshes are first-class objects — boolean-combinable with native primitives, transformable, and re-exportable into any assembly.

F-07

STEP Assembly — OpenCASCADE WASM

⬡ MEDUSA PROJECT

Full STEP assembly import/export powered by OpenCASCADE Technology (OCCT) compiled to WebAssembly. Multi-body AP203/AP214/AP242 import — names, positions and colors preserved. AP242 B-Rep export with assembly hierarchy. Core pipeline already validated in NassLab R&D (Fusion 360 ✓ FreeCAD ✓) — public release in active development.

// Primitives & Generators

Start fast with
what you need

Core primitives are one click. Advanced generators open a live-preview modal with sliders. 18 watertight primitives total.

Cube Sphere Cylinder Cone Half-Sphere Tube Roof Arc ⚙ Gear.Gen — ISO Involute ⚙ Gear.Gen — V-Groove Pulley ⌁ Pipe.Gen — Bishop Frame ◎ Torus Ultra-HD ✦ Chamfered / Rounded Cube ⌾ Truncated Cylinder · Double Chamfer ⌀ RevSolid.Gen — Solid of Revolution ◑ ArcSphere.Gen — Spherical Sector 🔩 Screw.Gen — ISO 68-1 / UNC·UNF ⬡ Nut.Gen — ISO 4032/4033 · ASME B18 M Threaded Fastener
NassScript — Stellate Crown demo
// Clear scene objs.forEach(o => { scene.remove(o.mesh); o.mesh.geometry.dispose(); }); objs = []; updStats(); // Place central torus showToreDialog(); _toreRebuild(); await delay(300); _toreToScene(); // Orbit 6 spheres as holes const N = 6, R = 70; for (let i = 0; i < N; i++) { const a = (2 * Math.PI * i) / N; addPrimitive('sphere'); const o = objs[objs.length - 1]; o.mesh.position.set( Math.cos(a)*R, 8, Math.sin(a)*R ); setHoleMode(true); await delay(200); } // Boolean — auto-subtract on mix selObjs = [...objs]; await doCSG('union');
// NassScript

JS console —
full internal access

NassScript exposes every NASSCAD function directly. Native async/await lets you script time-sequenced operations — create parts, apply booleans, animate the camera — all in one pass.

  • Access all internal functions from the console
  • Native async/await for time-sequenced operations
  • History of the 20 last runs
  • Ctrl+Enter to execute instantly
  • Chain booleans, animate, procedurally generate
Open and try it →   Read the docs →
// In Action

Real parts.
Real complexity.

NexStar 8 SE telescope mount adapter — imported STL, X-Ray inspection, live dimension annotations. 45 000 vertices, 60 fps.

NASSCAD X-Ray mode — NexStar 8 SE telescope part wireframe inspection
X-Ray mode · NexStar 8 SE raccord pied · 45 156 vertices · 15 052 faces · 60 fps
NASSCAD X-Ray wireframe mode with full UI — imported mechanical part
X-Ray wireframe · full UI · Import STL/OBJ/3MF/GLB/PLY
NASSCAD live 3D dimension annotations and properties panel
Live cotations · 60×115×60 mm · Properties panel · dark mode
NASSCAD CSG performance — 200 spheres union, 19.5M vertices, 5 seconds, 60 fps
CSG Union · 200 objects · 19.5M vertices · 5.0s · 60 fps · Manifold WASM
// Export & Import

From browser to
slicer, CNC or cloud

Eight export formats. Six import formats. Dimensions guaranteed 1:1. Section cuts for laser and CNC direct from the viewport.

.STL

Binary — Cura, PrusaSlicer,
Bambu, Simplify3D

.STL

ASCII — Human-readable,
text-based format

.OBJ

Wavefront — Blender,
MeshLab, most 3D tools

.3MF

3MF — Bambu Studio,
PrusaSlicer, full metadata

.GLB

Binary GLTF 2.0 — Sketchfab,
Blender, AR/VR, web 3D

.PLY

Stanford PLY — MeshLab,
CloudCompare, scan tools

✂ Section

SVG + DXF — 2D cut at any Y plane.
Laser cutters, CNC, LibreCAD

.STEP ⬡ MEDUSA PROJECT

AP242 Exact Analytical B-Rep — FreeCAD, Fusion 360,
CATIA, Autodesk Viewer
OCCT kernel · MEDUSA PROJECT · in active development.

No account. No subscription. No cloud.

Just a file that runs in your browser and exports parts straight to your printer or CNC.
The tool gets out of the way. You build.

Launch NASSCAD — Free →    Download Offline Package    Download AIO HTML

NASSCAD — Free Browser-Based Parametric 3D CAD, No Login Required

NASSCAD is a fully parametric 3D CAD application delivered as a single HTML file. It runs entirely in your browser via WebGL and WebAssembly — no server, no account, no installation. Open the page, model your part, export to your slicer.

The Best Free Alternative to Tinkercad, Fusion 360 and Onshape

Looking for a free alternative to Tinkercad that doesn't require a login? NASSCAD works anonymously, offline, and with zero cloud dependency — the ideal tinkercad alternative for 3D printing makers who value speed and privacy. Unlike Fusion 360, there is no subscription, no forced cloud save, and no 10-active-document limit. Unlike Onshape, your data never leaves your machine. It is also the best lightweight Fusion 360 alternative and a genuine browser-based CAD like Onshape — without the cloud lock-in.

Offline-Ready, Client-Side CAD — No Registration Needed

NASSCAD is a true offline browser-based CAD tool and a private cloudless CAD tool. Download the ZIP, unzip, open the HTM file in Chrome — it works with no internet connection. It is a free online CAD without registration and an anonymous 3D modeling tool: every computation runs client-side via Manifold WASM in a Web Worker, with a 2 GB GeometryPool, BVH raycasting, and IDB-backed undo. A zero setup 3D design app and a single file HTML 3D editor — auditable, open, and fast.

AIO HTML Package — Single-File Offline Build

The AIO (All-In-One) HTML package bundles NASSCAD — Three.js, Manifold WASM, fonts, every generator and the full export/import pipeline — into one standalone .htm file, distributed as a ZIP. Download it, unzip, and double-click the .htm file: it opens straight in your browser, works completely offline from then on, and needs no installer, no Node.js and no Electron runtime. It runs best in Chrome, which gives full WebAssembly and SharedArrayBuffer support for the 2 GB GeometryPool and Manifold CSG worker — Firefox and Safari work too, with reduced large-model performance. Ideal for USB sticks, locked-down machines, or anyone who wants the exact web app pinned to a specific version.

Offline Package — Native Electron Desktop App

The Offline Package is a native Electron desktop build of NASSCAD, currently for Windows. Electron wraps the same parametric CAD engine — Manifold WASM CSG core, 18 watertight primitives, NassScript, all generators — together with a bundled Chromium runtime and Node.js into a self-contained desktop application. It is available as a Windows setup installer (.exe) or as a portable, no-install version. No browser tab, no internet connection, no extra dependencies: launch NASSCAD like any other desktop software, fully offline. macOS and Linux builds are planned.

Boolean CSG, Parametric Generators, Full Export Pipeline

Visual OpenSCAD Alternative with GUI

NASSCAD is the OpenSCAD alternative with GUI and a visual OpenSCAD modeler that bridges the gap between code-first tools and point-and-click modelers. NassScript exposes every internal function via an async/await JS console — no separate IDE, no compile step.

Technical Architecture — Fast Client-Side CAD Engine

Built on Three.js r128 and Manifold WASM (Apache 2.0, Google). Worker Pool ×4/×6/×8, GeometryPool 2 GB with mark-and-sweep GC, BVH/AABB caching, IndexedDB undo/redo (200 levels). WebAssembly CSG modeling at full speed inside a lightweight WebGL 3D modeler. IndexedDB local 3D CAD logs. 18 watertight primitives. No external dependencies at runtime.

Also a free SelfCAD alternative, a SketchUp web alternative free, and a client-side 3D CAD software that respects user privacy. CC BY-NC 4.0 — NassLab, Nasser, France, 2026.

The code is open and readable. What can't be copied is the vision behind it.

NassLab has several ambitious projects in the pipeline — electronics, advanced WASM engines, aeronautics and more. NASSCAD is just the beginning.

NASSCAD Online is the free, single-file HTML edition. A native C++/Qt engine — same philosophy, same primitives, built for raw performance — is already in development.