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Plans & limits
NumaSim follows a simple rule: anyone can run any circuit, at any size. Opening a file, loading a sample, following a shared link, and running the simulation are always free and never need an account — the engine runs locally in your browser. You only need an account to create or edit circuits, and the size of a circuit you can build depends on your plan.
Think of it like a PDF: anyone can open and read one, but you need the editor to change it.
At a glance
| Guest (not signed in) | Free (signed in) | Pro (coming soon) | |
|---|---|---|---|
| Open / run / view any circuit | ✅ | ✅ | ✅ |
| Analysis (scopes, observables, plots) | ✅ | ✅ | ✅ |
| Create & edit circuits | — sign in | ✅ | ✅ |
| Max circuit size you can edit | — | 51 nodes / 200 components | Unlimited |
Import / save .numasim.json | open only | ✅ | ✅ |
| Price | Free | Free | Coming soon |
Pro is coming soon
The paid Pro tier isn't available yet. The first release ships with the Guest and Free plans only; unlimited editing arrives with Pro in a later release. Everything below describes how Pro will work once it lands.
What counts toward the free limit
The free edit cap has two parts, and a circuit is "over" if it exceeds either one:
- Electrical nodes — 51. A node is an electrical connection point (a net) in the circuit. Wires joined together count as one node.
- Components — 200. A component is a simulator part: a resistor, a source, a control block, a machine, and so on. Pure GUI helpers (labels, scopes, plain measurement read-outs) and the wires themselves do not count, and a three-phase part counts as one component (it still contributes its three nodes).
The Circuit info panel — open it from the hamburger menu — shows your current node and component usage against the limit (for example 12 / 51 nodes and 30 / 200 components) so you always know where you stand. Pro sees the same live counts with no limit, since nothing is capped.
How each plan behaves
Guest (not signed in). You can open, run, and view any circuit, and do analysis — pick observables, add scope traces, change plots. The first time you try to change the circuit itself (add or move a part, draw a wire, or edit a parameter) NumaSim prompts you to sign in. Your viewing and running are never interrupted.
Free (signed in). Build and grow a circuit freely up to the 51-node / 200-component ceiling. At the ceiling you can still delete parts and edit parameter values — you just can't add more until you make room. If you open a circuit that is already larger than the free cap (for instance a shared design or an imported case), it loads and runs fine; you drop into a "parameters only" mode where you can tweak values and run, but not add, remove, or rewire components. Pro (coming soon) will let you edit it structurally.
Pro (coming soon). No size limits. Build, import, and edit circuits of any size.
Why a limit at all?
Running is the part people want to share, so it stays free for everyone — it costs nothing extra because it happens on your own device. Editing large circuits is the power-user workflow, and Pro (coming soon) is what will fund ongoing development of the WebAssembly engine and the editor.
App plans vs. documentation gating
Two different "tier" systems live near each other; they are independent:
- App plans (this page) decide who may edit and how large a circuit may get. Some advanced components can also be marked as Pro-only in the palette — that's separate from the size cap; it controls which parts a plan may place, not how big a circuit may be.
- Documentation gating decides whether a docs page is in this site's bundle. A page opts in with a
tier:field in its YAML frontmatter:
yaml
---
tier: pro
---The docs build (docs/.vitepress/tierGate.ts) replaces the body of a gated page with a stub at build time. The page keeps its route and metadata so search and link previews still work, but the content isn't shipped. When the cloud auth layer ships, the same tier: contract will be enforced at the edge based on the signed-in user's plan.
A note on enforcement
Today the size and edit checks run in your browser, so they are a product/UX boundary rather than a hard security wall. Real, unbypassable enforcement arrives with cloud execution (the backend proxy that streams large simulations). Running locally remains free regardless.