Regex Tester & Debugger
Test regular expressions with live match highlighting. See all matches, capture groups, and named groups in real time. Supports all JavaScript regex flags — g, i, m, s, u.
What is a Regular Expression?
A regular expression (regex) is a sequence of characters that defines a search pattern. Used in programming, text editors, and command-line tools, regex allows powerful text searching, matching, and manipulation. JavaScript regex supports capture groups, lookahead, lookbehind, named groups, and Unicode property escapes.
Frequently Asked Questions
g (global) flag finds all matches rather than stopping at the first. The i (case insensitive) flag matches regardless of letter case. Most text processing tasks need both flags together.() that capture the matched text as a separate result. Named groups use (?<name>...) syntax. They appear in the match list below the preview..* is greedy — matches as many characters as possible. .*? is lazy — matches as few as possible. For example <.*> greedily matches an entire HTML string while <.*?> matches each individual tag.Enjoying this tool?
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