Are named capture groups supported?

Yes. Named capture groups in the format (? pattern) are supported and displayed in the results table.

Regex Tester

//g

테스트 문자열

Last updated: 2026 · Free online tool

Free online tool to test regular expressions with real-time matching, capture groups, and replacement

1
Enter pattern — Enter the regular expression pattern.
2
Select flags — Select flags (g, i, m, s, u, y).
3
Enter test string — Enter the test string and match results are displayed in real-time.
4
Check results — Matched parts are highlighted in yellow and capture groups are shown in a table.
5
Replacement mode — In replacement mode, you can reference capture groups with $1, $2, etc.

Ten presets are provided including email, URL, IPv4, Korean phone number, HEX color, HTML tag, and date patterns.

Yes. Named capture groups in the format (?<name>pattern) are supported and displayed in the results table.

Pattern validity is checked in real-time, displaying a red border and error message.

When matching empty strings, lastIndex is automatically incremented, with a maximum limit of 10,000 iterations.

No. All regex processing is performed in the browser.