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Regex Tester

Test regular expressions with live match highlighting, capture group display, and common pattern presets.

Frequently Asked Questions

How do I test a regex pattern?

Enter your regular expression in the pattern field and your test string in the text area below. Matches are highlighted in real time as you type. You can also view captured groups and their positions.

What regex flags are available?

This tool supports standard JavaScript regex flags: g (global), i (case-insensitive), m (multiline), s (dotAll), and u (Unicode). Toggle them using the flag buttons next to the pattern input.

What are regex capture groups?

Capture groups are portions of a regex pattern enclosed in parentheses. They let you extract specific parts of a match. This tool displays each capture group separately so you can verify your pattern extracts the right data.