Online Tools

Regex Tester

Test JavaScript regular expressions against sample text with live match feedback.

Flags

Step by step

How to use Regex Tester

  1. 1

    Enter a JavaScript regular expression, flags, and the sample text to search.

  2. 2

    Run the pattern and adjust it while watching matches and capture groups update.

  3. 3

    Review highlighted matches and captured values before moving the expression into code.

Capabilities

What this tool handles

  • Live match highlighting
  • Support for common JS regex flags
  • Capture-group visibility for debugging patterns

Common uses for Regex Tester

  • Debug validation and extraction patterns against representative input.
  • Check how global, case-insensitive, multiline, or Unicode flags change matching.

What to check before using the result

Regular-expression syntax and behavior follow JavaScript and may differ from PCRE, .NET, Java, Python, or command-line engines.

Privacy and accuracy

Questions about Regex Tester

Does this tool upload my input?

The conversion or analysis runs in your browser. The application does not intentionally send the value you enter to a processing API. Standard hosting infrastructure can still receive request metadata when the page loads; see the privacy page for details.

Can I rely on the output without checking it?

Use the result as a focused development aid and verify it in the system where it will be used. Test representative edge cases and confirm the destination uses the same format, standard, and assumptions described on this page.

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