Simulate automata
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An interactive canvas for DFA, NFA, PDA, Turing machines, and more — built for students, educators, and curious minds.

What you can simulate

DFA / NFA

Place states, draw transitions, and test strings on deterministic and nondeterministic finite automata. Convert NFA to DFA with one click.

PDA / NDPA

Model stack-based computation with full stack alphabet support using input,pop/push notation. Deterministic and nondeterministic variants.

Single & multi-tape

Build Turing machines with accept, reject, and normal states. Multi-tape support with semicolon-separated transition segments.

Mealy / Moore

Design output-producing machines. Mealy outputs on transitions; Moore outputs on states. Both share the FA canvas workflow.

Thompson construction

Type a regular expression and watch it convert to an NFA via Thompson's construction, then optionally determinize to a DFA.

Advanced conversions

Generate a Generalized NFA from a saved FA to derive a regular expression, or extract a Context-Free Grammar skeleton.

How it works

Place states and draw transitions directly on an infinite canvas. Pan, zoom, and arrange automata side by side.

Select a saved automaton, enter an input string, and watch transitions highlight in real time as the machine runs.

Convert NFA→DFA, build a GNFA, generate a regex, or export your workspace as JSON to share or reload later.

Ready to build your first automaton?

No installation. No account. Just open and start drawing.