Regex Tester — Live Match Highlighting + Capture Groups
Test JavaScript / PCRE regular expressions with live match highlighting, capture groups, and replace preview. Supports global, case-insensitive, multiline flags. 100% client-side.
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—Capture Groups
Common regex patterns
\w+@\w+\.\w+— Email (simple)https?:\/\/[^\s]+— URL\d{4}-\d{2}-\d{2}— Date (YYYY-MM-DD)^\s*$— Empty line (usemflag)(?<name>\w+)— Named capture group
Flag reference
- g — global, find all (not just first)
- i — case-insensitive
- m — multiline,
^ $match per line - s — dotall,
.matches newline - u — Unicode mode