Regex Toolkit

Test, explain, and debug regular expressions with live matches and a backtracking-risk check.

Regex Toolkit

Compile a JavaScript regular expression, test it against your own text with every match and capture group highlighted, and read a plain-language breakdown of what the pattern does — all in your browser.

Pattern and flags

Runs entirely in your browser.

Test text

References

MDN: Regular expressions
ECMAScript Language Specification: RegExp
OWASP: Regular expression Denial of Service (ReDoS)