⚙️ Developer Tools
Regex Tester
Test regular expressions with live match highlighting. See match count, captured groups and flags in real time.
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Type your test string here or paste some text…
0
Matches
0
Groups
0
Chars
❌ Invalid regex pattern
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Free Online Regex Tester — Test Regular Expressions Instantly
Our free regex tester highlights matches in real time as you type, showing match count, positions and captured groups. Used by developers, data analysts and system administrators for pattern matching and text processing.
🔍 Live Matching
Highlights matches as you type your regex.
📊 Match Details
Each match shown with position and captured groups.
🚩 All Flags
g, i, m, s flags supported.
✅ Syntax Validation
Regex errors shown immediately.
How to Use — Step by Step
1
Enter your regex
Type your pattern in the regex field (without slashes).
2
Set flags
Enable g (global), i (case-insensitive), m (multiline) as needed.
3
Enter test text
Paste the text you want to match against.
4
Read results
Matches highlighted in text. Each match listed with position and captured groups.
Frequently Asked Questions
What regex flavour does this use?
JavaScript regex (ECMAScript). Similar to PCRE used in PHP and Python but with some differences in lookbehind support.
What does the g flag do?
Global — finds all matches, not just the first. Always use g to find or replace all occurrences.
What does the i flag do?
Case-insensitive — matches regardless of letter case.
How do I match a literal dot?
Escape it with a backslash: \. — without backslash, . matches any character.
Difference between + and *?
* matches zero or more. + matches one or more. a* matches "", "a", "aa" etc. a+ requires at least one "a".
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