What regex engine does this tool use?

The tool uses JavaScript's built-in RegExp engine, which follows the ECMAScript specification.

What flags can I toggle?

Global (g), case-insensitive (i), multiline (m), and dot-all (s) flags can each be toggled independently.

How do I match a pattern across multiple lines?

Enable the multiline (m) flag for ^ and $ to match line boundaries. Enable dot-all (s) to make . match newline characters as well.

Regex Tester

Write a regular expression, configure your flags, and test it against a sample string with live match highlighting and a detailed match table showing index, matched text, and capture groups. Pattern errors are caught and explained in real time. A fast way to build and verify regular expressions before dropping them into code.

Frequently Asked Questions

What regex engine does this tool use?: The tool uses JavaScript's built-in RegExp engine, which follows the ECMAScript specification.
What flags can I toggle?: Global (g), case-insensitive (i), multiline (m), and dot-all (s) flags can each be toggled independently.
How do I match a pattern across multiple lines?: Enable the multiline (m) flag for ^ and $ to match line boundaries. Enable dot-all (s) to make . match newline characters as well.

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