Regex Tester

Test JavaScript regular expressions live: matches are highlighted as you type, capture groups are listed, and you can preview a replacement. Everything runs in your browser.

Flags: g global, i ignore case, m multiline, s dot matches newline, u Unicode, y sticky.

Test string Contact anna@example.com or Bob@Test.com. Not an email: carol@site.org

Highlighted matches

Match details

Replace

Replacement (use $1, $2, $&, $<name>)

Tips

• This tester uses your browser's JavaScript RegExp engine, so results match what String.prototype.match/replace do in JavaScript. Other engines (PCRE, Python, .NET) differ in details such as lookbehind support and named-group syntax.
• Without the g flag only the first match is found.
• Need a starting point? See the regex cheat sheet for email, URL, date and phone patterns, or extract them directly with Extract Emails & URLs.