Developer Tools

Regex Tester

Test and debug regular expressions in real time with instant match highlighting. Supports JavaScript regex syntax with flags.

Matches: 0

How to Use

  1. 1 Enter your regular expression pattern in the pattern field.
  2. 2 Set flags (g for global, i for case-insensitive, m for multiline).
  3. 3 Type or paste your test string in the text area.
  4. 4 Matches are highlighted instantly and listed below.

Benefits

Real-time match highlighting as you type
Supports all JavaScript regex flags (g, i, m, s, u)
Shows match details including groups and positions
No server-side processing — your code stays private

Frequently Asked Questions

What regex flavor does this use?

This tool uses JavaScript RegExp, which is the same engine used in browsers and Node.js. Most common patterns work the same as in Python, Java, and other languages.

How do I match across multiple lines?

Add the "m" flag. This makes ^ and $ match the start and end of each line, not just the entire string.

Can I test named capture groups?

Yes. Use the syntax (?<name>pattern) and named groups will be shown in the match results.

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