Regex Tester
Write a regular expression and see every match light up in your text as you type. Capture groups, named groups and replacements are shown too. Uses the JavaScript regex engine.
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Test string
Matches
Replace
Questions
Which regex flavour is this?
JavaScript (ECMAScript), the same engine your browser and Node.js use. It supports lookbehind, named groups (?<name>…) and Unicode property escapes like \p{L} with the u flag. Most patterns behave the same in Java, Python and PCRE, but check advanced features.
What do the flags do?
g finds every match instead of the first. i ignores case. m makes ^ and $ match at each line. s lets . match newlines. u turns on full Unicode. y only matches at the current position.
How do I use groups in the replacement?
Use $1, $2 and so on for numbered groups, $<name> for named groups, and $& for the whole match.