Freedom251 › Physics Simulation Software
Physion
What Physion is
Physion is a browser-based 2D physics simulator for designing and running interactive experiments. In a modern desktop browser, users can create scenes with circles, rectangles, capsules, polygons, text bodies, polylines, spirals, gears, joints, springs, and ropes. It simulates liquids, soft bodies, and particle emitters, and includes boolean shape operations and laser rays that reflect from surfaces. JavaScript Node Scripts can respond to object lifecycle and collision callbacks, use the physion global, and import external libraries. Live graphs cover motion, force, momentum, and energy, while free-body diagrams show several force types. Scenes can be shared by URL. Building, running, and opening scenes are unlimited, but saved scenes are metered monthly. The free plan allows one saved scene monthly with advertising; Basic costs $6 a month and Pro costs $10 a month.
Who it suits
Physion suits teachers, students, and hobbyists making classroom demonstrations, experiments, and mechanical creations. It is also useful for users who want browser-based scripting and physics visualizations.
What it does well
- Runs in a desktop browser without installation
- Includes varied shapes, joints, springs, and ropes
- Supports liquids, soft bodies, and particles
- Provides JavaScript scripting for object behavior
- Offers live graphs and free-body diagrams
What to know first
- Requires an internet connection
- Mobile drawing and editing are disabled
- Free plan saves one scene per month
- No offline downloadable app mode
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Free | Free forever, no trial · 1 saved scene per month · ad-supported · publish and share scenes with a link | Free |
| Basic | $6/mo or $60 a year · 12 saved scenes per month · no ads | $6 a month |
| Pro | $10/mo or $100 a year · 30 saved scenes per month · no ads · premium support | $10 a month |
As physion.net lists them, read 28 Sept 2026. The maker's own page has the final word.
Verdict
Physion provides broad 2D experiment-building tools, scripting, and analysis visuals directly in a browser. Users should account for its online requirement and monthly scene-save limits.
Facts from Physion's own pages
- Authentication and billing integrations
- Accounts use Google or Facebook sign-in, while paid subscriptions are handled through Stripe inside the app. · physion.net, 28 Sept 2026
- Authoring tools
- Yes · physion.net, 20 Sept 2026
- Boolean and laser tools
- The simulator provides boolean operations for combining or cutting shapes and laser rays that reflect off surfaces. · physion.net, 28 Sept 2026
- Browser and installation
- Physion runs in a modern desktop browser with no download, installer, plugin or browser extension, and scenes can be shared by URL. · physion.net, 28 Sept 2026
- Delivery mode
- web · physion.net, 20 Sept 2026
- Free plan
- Yes · physion.net, 20 Sept 2026
- Graphs and force diagrams
- Physion includes live graphs for motion, force, momentum and energy properties and free-body diagrams showing gravity, normal, friction, joint-reaction and spring forces. · physion.net, 28 Sept 2026
- JavaScript scripting
- Users can attach standard JavaScript Node Scripts to objects, handle lifecycle and collision callbacks, access the physion global and import external JavaScript libraries. · physion.net, 28 Sept 2026
- Liquid and particle simulation
- Physion simulates liquids, soft bodies and particle emitters using particle simulation. · physion.net, 28 Sept 2026
- Mobile limitation
- Phones and tablets can open, watch and interact with existing scenes, but drawing and editing tools are disabled there. · physion.net, 28 Sept 2026
- Offline access
- No · physion.net, 20 Sept 2026
- Offline limitation
- Physion requires an internet connection, stores saved scenes on its servers and has no offline or downloadable local app mode. · physion.net, 28 Sept 2026
- Open-source status
- The Physion app is not open source, although the physion-assets and physion-translations companion repositories are public and open to contributions. · physion.net, 28 Sept 2026
- Security and processing
- Physics calculations run locally in the user's browser rather than on a server, and Physion says it never sees card details because Stripe handles billing. · physion.net, 28 Sept 2026
- Shape and mechanism tools
- It supports shapes including circles, rectangles, capsules, polygons, text bodies, polylines, spirals and gears, plus joints, springs and ropes. · physion.net, 28 Sept 2026
- Paid from
- 6 · physion.net, 20 Sept 2026
- Support
- Users can ask questions or discuss school and classroom needs on Discord, and the Pro plan includes premium support. · physion.net, 28 Sept 2026
- Target users
- The maker describes Physion for teachers, students and hobbyists building classroom demonstrations, experiments and mechanical creations. · physion.net, 28 Sept 2026
- 3D visuals
- No · physion.net, 20 Sept 2026
- Usage limits
- Only account scene saves are metered; building, running and opening scenes are unlimited, with the monthly save count resetting at the start of each calendar month. · physion.net, 28 Sept 2026
- What it does
- Physion is a browser-based 2D physics simulator for designing and running interactive physics experiments. · physion.net, 28 Sept 2026
Where Physion stands on Freedom251
- Physics Simulation Software#58 of 89