OwlCAD

OwlCAD is a parametric 3D modeller that runs in a browser tab. It fills the gap between Tinkercad, which most people outgrow, and Fusion 360 or Onshape, which mean an install, an account and a learning curve.

Parametric, so nothing is baked in. A dimension you set on day one is still editable on day thirty, and changing it rebuilds the model instead of making you redo the work. Booleans are manifold by construction, so exports don't carry the ghost geometry that makes a slicer complain.

It knows about 3D printing. Clearance presets for press, slip and loose fits size holes and slots correctly for FDM. A printability check tints overhang surfaces, flags thin walls and tells you whether the mesh is watertight before you export. It will also hollow a solid, lay it flat and fit it to your printer's build volume.

Real modelling tools. Sketches with constraints, per-edge fillets and chamfers, patterns, sweep and loft, and assemblies with mates, a bill of materials and an exploded view. Thirty-two generators cover the parts nobody wants to model by hand: gears, threads, enclosures, Gridfinity bins, bearings, hinges and springs.

Scripting if you want it. OwlCAD reads and evaluates OpenSCAD, with a live script editor and customizer parameters. None of it is required.

Files. Imports STL, 3MF, OBJ, STEP and OpenSCAD. Exports STL, 3MF, OBJ, GLB, STEP, DXF, SVG.

Pricing. The editor is free and needs no account to start. Projects are private by default and you keep full commercial rights on every plan, Free included. Pro is $12/month or $120/year and adds AI generation with 20 credits a month, editing by chat, and AI agent access over MCP from Claude Code, Desktop or Cursor. Bring your own provider key and generation costs no credits. One-time credit packs are $5, $8 and $15 and never expire.

Classrooms are free, with pseudonymous student accounts, teacher controls and a signable district data agreement.