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JavaScript Regex Tester

Test JavaScript regular expressions against sample text with visible match results.

Regular Expression Pattern

Test Text

Flags

Active flags: /\b\w+@\w+\.\w+\b/g

Preset Patterns

Highlighted Text

Hello world! My email is [email protected] You can also reach me at [email protected] Invalid emails: test@, @domain.com, user@domain

Matches (0)

No matches found

Pattern Explanation

\b - Word boundary
\w - Word character (alphanumeric + underscore)
. - Any character (except newline)
+ - One or more occurrences

Working with JavaScript Regex Tester

Check a pattern in the browser's JavaScript regex engine before moving it into your code. Flags affect matching behavior, so keep them visible while comparing examples. Include edge cases that should not match as well as expected successes.

How to use JavaScript Regex Tester

  1. Enter a regular expression and select its flags.
  2. Paste representative matching and non-matching text.
  3. Inspect highlighted matches, groups, and replacement behavior when needed.

JavaScript Regex Tester example

Test ^cat$ with and without the multiline flag against a three-line sample to inspect how anchors behave.

What to expect from the result

Results follow the current browser's JavaScript regex support. Other engines, including PCRE and Python, can interpret patterns differently.

JavaScript Regex Tester questions

How do I use JavaScript Regex Tester?

Enter a regular expression and select its flags. Paste representative matching and non-matching text. Inspect highlighted matches, groups, and replacement behavior when needed.

What should I check in the result?

Results follow the current browser's JavaScript regex support. Other engines, including PCRE and Python, can interpret patterns differently.

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No registration, no tracking of your content, no server uploads. Don't just take our word for it:

No server, no uploads

Your files and text are processed entirely on your device. Nothing is ever sent to us.

Works offline

Once loaded, this tool keeps working with your Wi-Fi turned off. Try it.

Verify it yourself

Open your browser's DevTools → Network tab. You'll see zero requests carrying your data.