Regex Tester

Sample patterns to try

How to use this regex tester

1. Enter your pattern in the box between the slashes /.
2. Set flags by clicking g (global), i (case-insensitive), m (multiline), s (dot-all), or u (unicode). Clicking toggles each flag.
3. Type or paste text into the test area. Matches highlight in real time.
4. Try Replace mode to test find-and-replace with $1, $2 backreferences.
5. Click sample patterns above to load and test common regex examples instantly.

Common flags

• g — Global: find all matches, not just the first.
• i — Case-insensitive: ignore letter case.
• m — Multiline: ^ and $ match line boundaries, not just string boundaries.
• s — Dot-all: . matches newline characters too.
• u — Unicode: enable full Unicode matching (use \p{...} for categories like \p{L} for any letter).

What is a regular expression?

A regular expression (regex) is a sequence of characters that defines a search pattern. JavaScript supports PCRE-like syntax with features like lookaheads, lookbehinds, named groups, and Unicode property escapes. This tool runs the native JavaScript RegExp engine — the same one used in modern browsers and Node.js.