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Regex Tester

Test JavaScript regular expressions in your browser in real time. Highlights matches, shows capture groups, supports all flags.

✅ 100% free, no signup, runs entirely in your browser

/ /

Highlighted result

Match details

Common patterns

If something is broken or not displaying correctly, let us know via the contact form.

📖 How to Use

  1. 1
    Enter your pattern
    Type your regex (e.g. \\d{3}-\\d{4}). Toggle flags (g / i / m / s) as needed.
  2. 2
    Paste test text
    Paste target text and matches are highlighted in real time.
  3. 3
    Inspect capture groups
    Right panel shows position and capture group values for each match, plus replace preview.

❓ FAQ

Which regex engine is used?
It uses the browser JavaScript (ECMAScript 2018+) engine — supports lookbehind, Unicode properties, named groups. Syntax differs slightly from PCRE or POSIX.
Can I match Japanese character classes?
Yes. Use Unicode property escapes: \\p{Script=Hiragana} / Katakana / Han. Requires the u flag.
How fast is it?
Direct JS engine — matches several MB instantly. Beware of catastrophic backtracking (ReDoS) patterns.
Can I convert to regex in other languages?
Use "Copy as code" to export for Python re, PHP preg, Go regexp, Java Pattern — with proper backslash escaping.