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FizzKit

Regex Tester

Write regex patterns and see matches highlighted in a test string as you type. Shows capture groups, named groups, and match indices. Supports all JavaScript regex flags.

Runs locally in your browser
//
Test string
204 chars · 4 lines
Highlights
Contact: [email protected], +1 (555) 234-9876
Visit https://fizzkit.dev for more information.
Alternate: [email protected], phone 555.123.4567.
Invalid email: not@valid, and bad-url: htp://oops.
Matches (2)
#RangeMatchGroups
0[9..24][email protected]
1[103..132][email protected]
Matches
2
Flags
gi
Unique
2
Test string
204 chars
Valid
yes

About Regex Tester

Write regex patterns and see matches highlighted in a test string as you type. Shows capture groups, named groups, and match indices. Supports all JavaScript regex flags.

Regex Tester is part of FizzKit — a collection of focused, browser-based tools. Because everything runs locally, it works offline once loaded and never exposes your data to a remote server.

Frequently asked questions

JavaScript (ECMAScript) regex. Most features match PCRE, but backreferences and lookbehinds have slightly different syntax in some cases.