Workflow State Machine Simulator

Simulate a workflow state machine free online. Define states and transitions, then trigger events to watch the workflow move between states in real time.

States

Transitions (From State + Event → To State)

Current State

Browser only -- real state machine logic.

How to Use This Tool

Define your statesThe full set of possible statuses

Define valid transitionsWhich events move from which state to which

Trigger events and watch it moveInvalid transitions are rejected

Making Every Valid Move Explicit

Modeling a workflow as a formal state machine -- a defined set of states with explicit, named transitions between them -- forces every possible status and every valid move to be stated outright, rather than scattered implicitly across conditional logic in code. This simulator lets you define and test that structure directly.

Why Rejecting Invalid Transitions Is the Point

A real workflow has rules about what can happen next from any given state -- an order can't go from "pending" directly to "delivered" without passing through "shipped," for instance. This simulator enforces exactly that: triggering an event with no matching transition from the current state is rejected and logged as invalid, surfacing exactly the kind of gap that would otherwise become a confusing bug in production code.

Frequently Asked Questions

A state machine represents a system as a defined set of states with specific allowed transitions between them, triggered by events -- modeling a workflow this way makes every possible status and every valid move between statuses explicit, rather than implicit in scattered code logic.

It maintains one current state at a time, and when you trigger an event, checks whether a transition exists from the current state for that specific event -- if so, it moves to the new state and logs the transition; if not, it reports that the event isn't valid from the current state.

A real workflow (like an order status: pending → shipped → delivered) shouldn't allow skipping or reversing certain steps arbitrarily. Explicitly defining which transitions are valid from each state prevents the workflow from entering nonsensical or impossible states.

Yes, this isn't limited to a fixed example -- define whatever states and event-triggered transitions match your actual workflow, then test how it behaves.

Catching missing transitions, ambiguous states, or logic gaps before writing actual implementation code is much cheaper than discovering them after the workflow is already built into a real system.

Workflow State Machine Simulator

How to Use This Tool

Making Every Valid Move Explicit

Why Rejecting Invalid Transitions Is the Point

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Frequently Asked Questions