Test your regular expressions!

See exactly where your regex matches with live highlighting, plus groups, replace preview and ready-to-paste code!

pattern

//g

presets

testText

highlight

Contact: hong.gildong+news@json.kr, support@example.co.kr
Docs: https://json.kr/ko/dev/regex?tab=1
Server: 192.168.0.1 (not 999.1.1.1)
Phone: 010-1234-5678, 01098765432
RRN: 900101-1234567  BRN: 123-45-67890  Postal: 06236
Date: 2026-10-04 Time: 09:30:00
Color: #ffd43b, #1c1917
ID: 3f2b8c1e-9a4d-4c7e-8f1a-2b3c4d5e6f70
한글만
   indented line with trailing spaces   

replace

code

JavaScript/(?<user>[\w.+-]+)@(?<domain>[\w-]+(?:\.[\w-]+)+)/g

JavaPattern pattern = Pattern.compile("(?<user>[\\w.+-]+)@(?<domain>[\\w-]+(?:\\.[\\w-]+)+)");

Pythonpattern = re.compile(r"(?P<user>[\w.+-]+)@(?P<domain>[\w-]+(?:\.[\w-]+)+)")

Test your regular expressions!

See exactly where your regex matches with live highlighting, plus groups, replace preview and ready-to-paste code!

Use cases

- Check a regex instantly - Matches are highlighted as you edit the pattern, and group values are shown in a table. - Preview find & replace - Preview replacements using $1 or $<name> and copy the result. - Paste into code - Copy the pattern escaped correctly for JavaScript, Java or Python. - No frozen tabs - Patterns with catastrophic backtracking are stopped after 1 second instead of freezing the browser.