Regex Matcher
Test regular expressions against your text and see every match highlighted live as you type.
About Regex Matcher
Regular expressions are powerful but unforgiving, because a pattern that works in your head often matches nothing, or worse, matches everything. Testing against a live text sample catches those mistakes instantly instead of finding them in production.
Enter a pattern, choose flags like g, i, m, or s, and every match highlights in the text area as you type. JavaScript's standard RegExp syntax is supported, including character classes, quantifiers, groups, alternation, and lookarounds, and capture groups are listed below for debugging.
Developers building validators and parsers, data analysts extracting patterns from text, and anyone learning regular expressions benefit from the live feedback. It is also the fastest way to sanity-check a pattern before using it in code.
How to Use
- Enter a regular expression pattern.
- Select flags like global, case-insensitive, or multiline.
- Watch every match highlight in the text area in real time.
Example
Pattern: \d+ on "There are 12 apples and 3 oranges" Matches: 12, 3
\d+ matches one or more digits. The global flag finds both '12' and '3', with each highlighted inline.
FAQ
Which regex syntax is supported?
JavaScript's standard RegExp syntax, including character classes, quantifiers, groups, alternation, and lookarounds.
What do the flags do?
g finds all matches, i ignores case, m changes ^ and $ to match line boundaries, and s makes the dot match newlines.
Does it show capture groups?
Yes, matched groups are listed under the highlights so you can debug complex patterns.
Why would I use the multiline flag?
With the m flag, the anchors ^ and $ match at the start and end of each line instead of the whole string, which is essential when pattern-matching across multi-line text.
Can lookaheads be used in patterns?
Yes, lookaheads like (?=...) and negative lookaheads (?!...) are fully supported, so you can match text followed by a condition without consuming that condition in the match.