RegEx Tester

Test regular expressions in real time with capture group highlighting

JavaScript engine

Uses JavaScript regex (V8). Behavior may differ from PCRE / RE2 / POSIX engines used on servers — verify on your target engine before deploying patterns to production.

Pattern

Flags

g

Global — find all matches

i

Case insensitive

m

Multiline — ^ $ match line boundaries

s

Dotall — . matches newlines

Test string

Replacement ($1, $<name>)

Matches

2 matches

[email protected] and [email protected]

#	Match	Group 1	Group 2
1	`[email protected]`	`hello`	`example.com`
2	`[email protected]`	`world`	`test.org`

How to use

Type your regular expression in the pattern field.
Toggle flags such as g (global), i (ignore case), and m (multiline).
Paste the text to test against in the input area.
Matches are highlighted live, and capture groups are listed for each match.

Examples

The pattern \b\d{4}-\d{2}-\d{2}\b matches dates like 2026-05-26 inside a longer text.
Using the pattern (\w+)@(\w+) highlights each capture group so you can see what group 1 and group 2 captured.

Verify outputs before using in production. No warranty — see Terms.