ByteBox / Tools / Regex Tester

Regex Tester

Test JavaScript regular expressions with live match highlighting and group capture.

Last updated: Mar 15, 2026
/ /
Enter a pattern above
Matches

Regex Tester Features

This RegExp tester executes standard JavaScript RegExp patterns against your text. It highlights exactly where your patterns match the test string and breaks down capture groups individually.

Regex Flags

By default, the g (Global) flag is enabled to highlight all matches within the text rather than just the first occurance. Use i for case-insensitive matching, and m to properly handle multiline anchors (^ and $).

Regex Quick Reference

. Any character
\d Digit
\w Word char
\s Whitespace
^ Start of line
$ End of line
* 0 or more
+ 1 or more
? 0 or 1
() Capture group
[] Character class
| Alternation