Regex tester
Live matching · capture groups · replace preview · pattern presets
정규식 테스터
정규표현식을 실시간으로 시험하고 매치·그룹·치환 결과를 확인합니다
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플래그 — g 전체, i 대소문자 무시, m 여러 줄, s 줄바꿈 포함(.), u 유니코드
help@karmolab.dev 로 보내고 cc 는 me@example.co.kr
치환 문자열을 입력하면 결과가 나옵니다
2개 매치
#1 @0help@karmolab.dev
#2 @29me@example.co.kr
이 정규식이 무슨 뜻인가 (조각 풀이 · 철길 그림)
[\w.+-]이 중 하나1번 이상
@이 글자 그대로
[\w-]이 중 하나1번 이상
.이 글자 그대로
[\w.]이 중 하나1번 이상
Test a regex (regular expression) live — matches highlighted as you type the pattern. It lists capture groups with their positions. Includes a replace preview and ready-made patterns for email, phone numbers and more.
How to use it
- Type the pattern and flags
- Type a test string — highlights appear instantly
- Check match positions and groups in the list
- Preview the outcome with a replacement string
Common questions
- Which regex flavour does it use?
- The browser’s own JavaScript (ECMAScript) engine. Syntax specific to Python or PCRE will not work.
- What does each flag mean?
- g searches the whole string, i ignores case, m makes ^ and $ work per line, s lets . match newlines, and u turns on Unicode handling.
- Are there patterns that freeze the browser?
- Nested repetition such as (a+)+b can slow down sharply on certain input. Matching stops at 5,000 hits here, but patterns like that are dangerous in production too, so they are best avoided.
Other tools
Stays on your device What you enter is handled inside your browser only — nothing is stored or sent anywhere.
This tool page states where what you enter goes — see the badge above. All tools · KarmoLab · Who made this · Built with AI. View source