TOOL
Regex to NFA
Convert a regex to a Thompson NFA with ε-transitions via formal construction — states, symbol and ε edges, start and accept states, computed entirely in your browser.
Try an example:
Local only
Recent history
No history yet
How to use
- Type or paste your input into the input box.
- Adjust any parameters if needed.
- Copy or download the result.
Frequently asked questions
- Is my data uploaded anywhere?
- No. All processing happens locally in your browser with no server round-trip.
- Does this tool work offline?
- Yes. Once the page loads, the tool runs entirely client-side and needs no network connection.
Related tools
Regex Complement
Compute the true complement of a regex language — every string it does not fully match — as a ready-to-use ^...$ pattern, via DFA inversion with minimization, in your browser. TOOL
Regex Contains
Regex Contains — pure client-side tool. Privacy-first, no server round-trip. TOOL
Regex Difference
Build a regex for 'strings matching pattern A but not pattern B' from two patterns, one per line. Semantics are asymmetric: A must match from the start of the string, while B is rejected if it occurs anywhere. Output shape: (?=A)(?!.*B).* TOOL
Regex Equivalent
Check whether two regexes match exactly the same strings — semantic equivalence via product-DFA analysis, with a shortest counterexample string when they differ. Input: two patterns on separate lines. TOOL
Regex Escape String
Regex Escape String — pure client-side tool. Privacy-first, no server round-trip. TOOL
Regex to DFA
Convert a regex to a DFA via subset construction — full transition table plus the minimized state count (Moore algorithm), computed entirely in your browser. TOOL