Regex Tester
Test JavaScript regular expressions with live match highlighting, capture groups, and flag controls. Runs entirely in your browser.
Match highlights
3 matchesCapture groups
| # | Match | Position | Group 1 | Group 2 |
|---|---|---|---|---|
| 1 | [email protected] | 8 | alice | example.com |
| 2 | [email protected] | 29 | bob | company.org |
| 3 | [email protected] | 70 | support | toolscoder.com |
Quick reference
\dAny digit (0–9)\wWord character (letter, digit, _)\sWhitespace (space, tab, newline).Any character except newline (with s flag: any)^Start of string (or line with m flag)$End of string (or line with m flag)*Zero or more of the preceding+One or more of the preceding?Zero or one of the preceding{n,m}Between n and m of the preceding[abc]Any of: a, b, or c(abc)Capture group(?:abc)Non-capturing group(?<name>abc)Named capture groupa|ba or bFrequently Asked Questions
What flags are available?+
g (global) — find all matches instead of stopping at the first. i (case-insensitive) — treat uppercase and lowercase as equal. m (multiline) — make ^ and $ match the start and end of each line, not just the whole string. s (dotAll) — make the . character match newlines as well as other characters. u (unicode) — enable full Unicode matching with correct handling of astral-plane characters.
Why do some special characters need to be escaped?+
In a regular expression, characters like . * + ? ( ) [ ] { } \ | ^ $ have special meaning. To match them literally, prefix them with a backslash: \. matches a literal dot, \( matches a literal parenthesis. This tester accepts the pattern without surrounding slashes — just the pattern content.
What are capture groups?+
Parentheses in a pattern create capture groups that extract substrings from each match. The group /(\w+)@(\w+)/ applied to "user@host" captures "user" as group 1 and "host" as group 2. Named groups use the syntax (?<name>pattern) and appear with their name in the results.
Is my text sent to a server?+
No. All matching runs in your browser using the built-in JavaScript RegExp engine. Your pattern and test text never leave your device.
Related Tools
How to use
- Enter your regex pattern — no surrounding slashes needed.
- Toggle flags with the buttons: g, i, m, s, u.
- Paste your test string — matches highlight instantly.
- Capture groups appear in the table below the highlighted output.