TOC Playground
Build automata and grammars. Test words, compare languages, and inspect conversions.
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Finite automata and regular expressions
Build deterministic and nondeterministic finite automata (DFA and NFA). Convert between automata and regular expressions, test word membership, minimize a DFA, and compare regular languages with an exact algorithm. A difference includes a shortest distinguishing word.
Grammars and pushdown automata
Write context-free grammars with typed source, autocomplete, and structured controls. Inspect parse trees, convert grammars to Chomsky or Greibach normal form, and convert between grammars and pushdown automata. General grammar equivalence and ambiguity are undecidable; bounded searches and supported proof procedures report when they cannot decide.
Step through a computation
Run a word through a finite automaton, pushdown automaton, Turing machine, two-stack machine, or queue machine. Pause, step, change the speed, and inspect states, tapes, stacks, and queues. A bounded run can end without deciding membership.
Edit, save, and share
Drag states, edit transitions, and switch between diagrams and tables. Work is saved in this browser. Share a compressed workspace link or export a readable .automata file, JSON, or a machine diagram as SVG. Four color themes and reduced-motion support change presentation without changing the language.