Skip to main content

Interactive Physics Simulations

Online app for designing and simulating physics experiments

Educational Simulations

Create interactive physics simulations to demonstrate basic physics concepts in the classroom.


Physics Sandbox for Fun!

Use Physion to create any kind of mechanism and simulate it in real-time.

Continuous Improvement

Let us know for ways we can improve Physion.

What is Physion?

Physion is a free physics simulation software which allows you to design and simulate realistic physics experiments in a virtual physical world. You can think of it as a CAD application combined with a 2D physics engine where the objects you design can be instantly simulated.

Using Physion you can create interactive physics simulations using simple drawing tools such as rectangles, circles, polygons, regular polygons, text, polylines, spirals, gears, ropes and springs. The application also supports linking objects together using joint constraints (e.g. axles, rods, pulleys, springs). This way you can create various scenes/scenarios which can range from simple educational experiments to complex structures and mechanisms.

Physion also supports scripting with JavaScript. The user can write custom scripts in order to enhance their creations with custom behaviors and functionality.

For more information on how to use the app, please visit our docs page.

Key Features

  • Create a variety of shapes (rigid bodies) within your Scene.
  • Link objects together using joint constraints.
  • Instantly simulate your creations.
  • Perform boolean operations (union, difference, intersection).
  • Simulate liquids and soft-bodies.
  • Tweak physical properties (such as gravity, friction, density, spring constant, etc.) with the aid of the Property Editor.
  • Use scripting (JavaScript) to enhance your creations with extra functionalities.
  • Web Application:
    • Runs directly in the browser (no download or installation required).
    • User creations (scenes) can be easily shared and viewed by others.

Soon to be added features

  • Visualization Tools (force, speed, acceleration, etc.) and Graphs.
  • Optics simulation.
  • Custom UI components (e.g. sliders, buttons, etc.).

You can always suggest a new feature using our feature request page.