Symbolic backend
Alias elimination, Pantelides index reduction with dummy derivatives, BLT sorting and tearing, and exact symbolic Jacobians, evaluated by a compiled register tape.
Free public beta · Modelica Standard Library 4.1 · in your browser
Model and simulate physical systems in your browser.
ModOnda compiles Modelica models to native code and WebAssembly, simulates them with its own solvers, and plots the results beside the diagram. Nothing to install, and the workbench is free to use.
Signing in is optional. The workbench runs without an account.
- 533 of 534
- MSL 4.1.0 example models run to the end
- 517 of 534
- match the Modelica reference results
- On your device
- simulations run in your browser tab by default
- Free
- public beta, nothing to install
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Built for models that are too big to wait on
A Rust core runs the same compiler and solvers on a server and in a browser tab.
Solvers you can choose
Variable-order BDF, Radau IIA and ESDIRK with colored Jacobians and dense or sparse LU. Dopri5 switches to BDF when a model turns stiff. RK4 and Euler are there for fixed steps.
Events and discrete logic
Zero-crossing events, when, elsewhen and reinit, and state machines drawn as diagrams.
Workbench in the Dymola style
Package browser, icon, diagram and text views of every class, a variable browser, a plot window with display units, and simulation setup in one place.
Standard Library ready
Modelica Standard Library 4.1.0 loads in the browser, including MultiBody, the QuasiStatic machines, Media (IF97 water, R134a, moist air) and Fluid. 3-D animation replays MultiBody models.
Results and scripting
Results go to Dymola-format .mat files or CSV, readable by Dymola, OMEdit and DyMat.
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Models to open and run
Each one opens in the workbench. Press Simulate and it runs in your browser tab, with nothing to install.
3-D animation · ModOnda examples
Two cars, one throttle
A full-throttle launch run twice: with a static torque converter, and with fluid build-up lag. Press play and watch them pull away.
Open in the workbench
3-D animation · MultiBodyVehicle
A suspension from its hardpoints
A multilink corner on a test rig, built from real mounting points on Modelica's MultiBody library.
Open in the workbench
Standard Library · Mechanics.MultiBody
A double pendulum, state by state
Two bars on revolute joints, replayed in 3-D. The Structure tab shows which four states the solver picked, and why.
Open in the workbench
Standard Library · Electrical.Analog
A circuit that never repeats
Chua's circuit is chaotic. Plot one capacitor voltage against the other to draw its double-scroll attractor.
Open in the workbench
Standard Library · Mechanics.Rotational
Three clutches, a dozen events
The clutches engage in turn and pull the shaft speeds together. The solver has to stop at every switch.
Open in the workbench
Linear analysis · ModOnda examples
Bode plots from the model itself
A quarter car with an active actuator. Open the Linear tab and press Analyze for its Bode plot, poles and step response.
Open in the workbench03
Inside the workbench
Every view below is a live part of the app, not a mock-up.
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Validated against the Modelica reference results
Every example of the Modelica Standard Library is run and compared, signal by signal, with the reference results published with the library. 517 of the 534 match, and 533 run to the end.
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From the blog
Worked examples, how the results are checked, and what is new. All posts
25 October 2026
ModOnda: Modelica simulation in a browser tab
ModOnda is a free public beta of a Modelica workbench that runs in your browser. Open a model, press Simulate, plot the results and watch the 3-D animation, with nothing to install.
25 October 2026
Your first simulation
Open the landing-gear drop test, press Simulate and read the result. A five-minute tour of the workbench with a model that has a clear answer.
25 October 2026
Validated against the Modelica reference results
How ModOnda is compared with the Modelica Standard Library's published reference results, example by example, what the numbers mean, and where the references themselves look wrong.
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Pricing
The beta is free, and it takes no payment. Pro is in early access and is not charged yet.
Prices for
Available now
Free
$0
- The full workbench and solvers, computed in your browser
- Documentation and worked examples
- Share a model by link
- Parameter sweeps of up to 20 runs
- Your own AI through an OpenRouter key or MCP
- Free for personal, educational and commercial work during the beta
Early access
Pro
$20 a month, or $200 a year, excl. tax
- Hosted AI assistant: 300 messages a month, no key of your own needed
- Run on server and 30 hours of cloud runs a month for models too big for a browser tab
- Parameter sweeps of more than 20 runs
- More assistant messages in packs of 50 for $5, 100 for $10 or 500 for $50
- Early subscribers keep this price for 12 months
Waitlist
Team
Later
- Shared workspaces for teams
- Price to be set with the first teams
Prices are in dollars and exclude VAT and other taxes. The total including any tax that applies to you is shown before you pay. Prices can change before Pro goes live. The paid parts are not live yet, and nothing is charged when you join a list.