NimbleTools

Regex Tester Online

Test regular expressions with live highlighting of matches and capture groups. Supports flags g, i, m, s, u — results update as you type.

Flags
Matches: 2
Contact us: hello@example.com or support@nimbletools.example.com
#MatchesGroups
1hello@example.com—
2support@nimbletools.example—

Frequently asked questions

Which regex flavor is used?

JavaScript (ECMAScript) regular expressions — the same your browser and Node.js execute.

What do the flags mean?

g — find all matches, i — ignore case, m — multiline ^ and $, s — dot matches newline, u — Unicode support.

Why is my regex slow?

Beware of nested quantifiers like (a+)+ — they cause catastrophic backtracking. Simplify the pattern or bound the repetitions.