What regex flavor does this use?

It uses your browser's native JavaScript RegExp engine — the same one used by Node.js and every modern browser, so patterns tested here work directly in JavaScript code.

Why isn't my pattern matching anything?

Check that the flags match your intent — for example, without the "g" flag only the first match is found, and without "i" the match is case-sensitive.

Is my test data private?

Yes, matching runs entirely in your browser's JavaScript engine — the pattern and text you enter are never sent anywhere.

Regex Tester

Test regular expressions against sample text with live match highlighting.

Regular expression

//gi

Ignore case (i)Multiline (m)Dot all (s)

Test string

2 matches

Reach the team at hello@utilrix.com or support@utilrix.com for help.

Processed 100% in your browser — nothing you enter here is ever uploaded.

Common use cases

Validating a form field pattern

Test an email, phone number, or postal code pattern against real examples before wiring it into a form's validation.

Debugging a log-parsing pattern

Figure out why a pattern misses certain log lines by testing it against the exact lines it's failing on.

Building a find-and-replace for a bulk script

Confirm a pattern matches exactly the text you intend before running it across hundreds of files in a rename or refactor script.

How to use the Regex Tester

Type your pattern in the regular expression field — no need to add the surrounding slashes.

Toggle flags like Global, Ignore case, Multiline or Dot all to change matching behavior.

Paste your test string below — every match is highlighted live as you type either field.

The match count and each matched substring are shown so you can confirm your pattern works before using it in code.