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
| # | Matches | Groups |
|---|---|---|
| 1 | hello@example.com | — |
| 2 | support@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.