JumpStart 3D is a free 3D design app that runs right in your web browser, with nothing to install. It’s for Makers of all ages: students, teachers, hobbyists and anyone curious about 3D printing who wants to go from an idea to a printed part without a steep learning curve. You can start simple by dragging shapes together, move up to sketch-based CAD with a feature timeline, or sculpt like digital clay, then send your design to a 3D printer. It isn’t meant to replace established professional CAD or 3D design programs. It began as a hobby project to help Makers jump into 3D design and printing with as little frustration as possible, and to give them a friendly first step before moving on to bigger tools. It was written from scratch with vibe coding assistance and built on well-known open-source libraries, such as the OpenCascade geometry engine and three.js. It is not reverse engineered from any other program. The full source code is available and open source under the MIT License, so you’re free to use it, study it, change it and share it.
Features
Three modes: Beginner (drag-and-drop shapes and holes), Advanced (sketch-based parametric CAD with a timeline) and Chisel (3D sculpting in Easy or Pro), with your design carrying over between them
CAD tools: extrude, revolve, sweep, loft, pipe, coil, fillet, chamfer, shell, holes, metric and imperial threads, and patterns (including along a path)
3D Sketch: draw tubes in 3D on a shape or in the air, with a split-screen camera, by touch, pen, mouse or trackpad
Lathe: turn wood blanks or your own models with chisels, a speed control, a foot pedal and flying chips, then hollow them out
Jump Brick Builder: turn any model into printable stud-and-tube building bricks, with a parts list and step-by-step building layers
Simulate: joints, motion studies, stress tests and print-strength checks, plus photo-style renders
3D printing: STL, 3MF, OBJ and STEP export, a 3D Print Sim preview and a 256 × 256 mm build plate
Import: STL, 3MF and STEP models, SVG and DXF drawings, and pictures to trace or puff up into 3D
Learning: 18 step-by-step tutorials with “Show me” pointers and animations
Works everywhere: Windows, Mac, Chromebook, iPad and phones, with touch support, light and dark themes, and mm or inch units