Regular Expression Analyser

Regular expression:

⤒

This tool visualises regular expressions as both nondeterministic and deterministic finite automata. Hovering the mouse pointer over a node in either automaton will highlight the corresponding node(s) in the other. Nodes can be repositioned by dragging to make the graph easier to follow.

As well as minimal regular expressions, the five widely-used syntactic extensions of once-or-more repetition with +, zero-or-one optional components with ?, n-to-m repetitions with {n,m} (both optional), character classes with [...] (including negated [^...] and range [a-d] classes), and an any-symbol match with . are supported. The alphabet for negated classes includes a, b, and c, and any symbol that has been used in an expression. There are no backreferences (which are non-regular) or special escape sequences.

In addition to the traditional extensions, the system supports conjunction with & to parallel disjunction with |.

For concision's sake, . is represented in the visualisations with any. In the NFA, this represents any symbol, while in the DFA it represents a default case when no other edge's symbol matched.

Link to this expression

Nondeterministic Finite Automaton

Deterministic Finite Automaton

Test a string: