How do I test a regex pattern online?

Enter your regular expression and test string in Toollo's regex tester to see live matches highlighted as you type. It supports JavaScript regex syntax with all flags (g, i, m, s, u).

Does the regex tester show capture groups?

Yes, Toollo's regex tester displays all matches along with their capture groups, match indices, and group names. This makes it easy to debug and refine complex patterns.

Is my test data private?

Completely. All regex matching runs in your browser with zero server communication. Your patterns and test strings never leave your device.

Regex Tester

Test regular expressions with live matching

Pattern

/g/i/m/s

//g

Test String140 characters

Matches

Enter regex pattern…

Replace

Replacement string (use $1, $2 or $<name> for groups)

Enter a pattern above to enable replacement.

Common Presets

FAQ

How do I test a regex pattern online?: Enter your regular expression and test string in Toollo's regex tester to see live matches highlighted as you type. It supports JavaScript regex syntax with all flags (g, i, m, s, u).
Does the regex tester show capture groups?: Yes, Toollo's regex tester displays all matches along with their capture groups, match indices, and group names. This makes it easy to debug and refine complex patterns.
Is my test data private?: Completely. All regex matching runs in your browser with zero server communication. Your patterns and test strings never leave your device.