What flavor of regex does this use?

Standard JavaScript regular expressions, the same engine used by every modern browser and Node.js. It supports capture groups, named groups, lookaheads, and lookbehinds.

What do the g, i, m, and s flags do?

g (global) finds every match instead of just the first. i makes matching case-insensitive. m makes ^ and $ match the start and end of each line instead of the whole string. s makes . also match newline characters.

Why do I only see one match?

Without the global flag, a regular expression only reports its first match, matching how JavaScript itself behaves. Turn on the g flag to find every occurrence.

Can I use capture groups?

Yes. Both numbered groups like (\d+) and named groups like (? \d{4}) are supported, and their captured values are listed under each match.

Is my data sent anywhere?

No. Matching happens entirely in your browser and nothing is sent to a server.

DAILYTOOLER

Regex tester

Test a regular expression against a string with live match highlighting, a match list, and capture groups.

Pattern

g — global

i — ignore case

m — multiline

s — dot matches newline

Test string

Preview (2 matches)

Matches

Match 1: "[email protected]" at index 14

Match 2: "[email protected]" at index 39

What is a regex tester?

Type a regular expression and a test string, and every match is highlighted live, with a full list of matches and their capture groups below. It uses the same JavaScript regex engine as your browser, so what works here works in your code.

Regex tester

What is a regex tester?

Frequently asked questions