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Our Vision
A high-quality simulator, accessible to everyone — on the web.
NumaSim brings professional-grade control, circuit, power-electronics, and power-systems simulation to the browser. No install, no license server.
Launch the app · Get started · Explore the concepts
What You Can Build
- Control systems — block diagrams, feedback loops, PID and digital logic. Design and tune controllers alongside the plant they drive. Browse control blocks
- Circuit simulation — full electromagnetic-transient waveforms from R/L/C networks: switching ripple, inrush, and fault transients, microsecond by microsecond. How EMT works
- Power electronics — switch-mode converters, rectifiers, and inverters with diodes and IGBTs. See the real switched waveform, not just the average model. Open a converter sample
- Power systems — three-phase networks, transformers, and transmission lines. Run a steady-state power flow and a full EMT study over the same single-line diagram. How power flow works
Why We Are Building This
Serious simulation has always meant heavyweight desktop tools: long installs, license servers, and a steep wall between "I have an idea" and "I can see a waveform." We think that wall is the problem.
NumaSim's goal is a simulator that is both high quality and accessible — fast enough for real engineering, yet open in a browser tab on any machine, for a student, a hobbyist, or a system operator alike. The same C++ EMT engine that powers a large study on the cloud runs locally as WebAssembly.
That foundation lets us aim further — toward an assistant that helps you build and reason about systems, and toward cloud compute that turns a single "what if?" into thousands of answers at once.
The Runway
Three milestones take us from a browser-native editor to AI-assisted, cloud-scale studies. We are here today at the first.
- Client-side simulation (available now) — build circuits and run them entirely on your device. No backend; all compute in the browser. Running and viewing any circuit needs no account — sign in (free) when you want to create or edit one. See Plans & limits.
- AI assistant (planned) — an AI agent with the tools to create, modify and analyze circuits, run simulations, and interpret the results.
- Cloud simulation (planned) — massively parallel studies in the cloud. Paired with AI: sweep contingencies, surface mitigations for operators.
Milestone 1 — Client-side simulation
The whole simulator runs on your device. You create circuits on the canvas and run them right in the web app; the EMT engine executes locally as WebAssembly. There is no backend compute in the cloud — nothing to provision, nothing to pay for per run, and nothing about your design that has to leave your machine. This is what NumaSim does today.
Because running is purely local, anyone can open and run any circuit without signing up. Creating and editing circuits is the part that uses an account: a free account edits circuits up to a generous size cap, and Pro (coming soon) will remove the cap. Full details on Plans & limits.
Milestone 2 — AI assistant
Next, an AI agent embedded in the app, equipped with the right tools to act on your behalf: create and modify circuits, wire components together, run simulations, and analyze the results. Instead of hunting through a palette, you describe what you want and the assistant builds, edits, and explains it — turning the editor into a collaborator.
Milestone 3 — Cloud simulation
Finally, optional cloud execution for studies too large for one device. Offloading to the cloud unlocks massively parallel simulation — running many scenarios at once. Paired with the AI assistant, this lets us study different contingencies across a system in parallel and hand the operator concrete mitigation strategies, not just a single waveform.
Curious where we are right now? Get started in your browser, or browse the components we already ship.