// free online tool

Regex Studio

Build, test, and debug regular expressions in real time. Matches highlight instantly as you type, with detailed match info and a built-in quick reference.

Live matching Match highlight Named groups All flags Quick reference Free forever
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Flags:
test string0 matches
matches highlighted
// matches will be highlighted here
Enter a pattern and test string above
// quick reference — click to insert
.Any character
\dDigit 0-9
\wWord character
\sWhitespace
\DNon-digit
\WNon-word
\SNon-whitespace
^Start of string
$End of string
*0 or more
+1 or more
?0 or 1
{n,m}Between n and m
()Capture group
(?:)Non-capture group
(?<n>)Named group
[]Character class
[^]Negated class
|Alternation (or)
\bWord boundary

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Live matching

Matches highlight in real time as you type your pattern — no button press needed. Instant feedback on every keystroke.

🎨 Match highlighting

Every match is highlighted directly in your test string so you can see exactly what your pattern is capturing at a glance.

📋 Match details

See every match listed with its value, index position, and length. Named capture groups are shown separately.

🚩 Flag toggles

Toggle global, case-insensitive, multiline, dotall, unicode, and sticky flags with one click — no need to remember the letters.

📖 Quick reference

Built-in cheat sheet of common regex tokens. Click any token to insert it directly into your pattern.

🔒 100% private

Your patterns and test strings never leave your browser. Safe to test against real data and sensitive strings.

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