Regex Tester

Test and debug regular expressions in real-time with match highlighting and capture groups.

Regex Pattern

Flags

Test String

What is Regex Tester?

Regex Tester is a free online tool for testing and debugging regular expressions (regex). Enter a pattern and test string to see matches highlighted in real-time, with capture group details.

How to Use Regex Tester

Enter your regular expression pattern
Set flags (g for global, i for case-insensitive, m for multiline)
Type or paste your test string to see matches highlighted

FAQ

What regex flavors are supported?

This tool uses JavaScript's built-in RegExp engine, which supports most common regex features.

What do the flags mean?

g = global (find all matches), i = case-insensitive, m = multiline (^ and $ match line boundaries).

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