REGEX PLAYGROUND
Live regular expression tester with match highlighting, group capture, flag toggles, and a library of common patterns. Runs entirely in your browser.
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// FAQ
FREQUENTLY ASKED QUESTIONS
Q1.What regex flavour does this use?
JavaScript (ECMAScript) regex — the same engine used in Node.js, browsers, and most JS frameworks. It supports all standard features including named capture groups, lookahead/lookbehind, and the s (dotAll) flag.
Q2.What do the flags do?
g (global) — find all matches, not just the first. i (ignore case) — match regardless of letter case. m (multiline) — ^ and $ match line boundaries, not just string start/end. s (dotAll) — dot (.) matches newlines too. u (unicode) — enables full Unicode support for \u{} escapes and Unicode property escapes.
Q3.How do I reference capture groups?
Wrap parts of your pattern in parentheses: (\d+). The Match Details panel shows each group's value as $1, $2, etc. For named groups, use (?<name>\d+).
Q4.Can I test multi-line strings?
Yes — just paste text with newlines into the test string area and enable the m flag if you want ^ and $ to match line boundaries.
Q5.What is the COPY JS button?
It copies your pattern as a JavaScript regex literal — e.g. /[a-z]+/gi — ready to paste directly into code.
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