Regex Tester & Visualizer

Test, debug, and visualize regular expressions in real-time

Pattern:

g i m s u

Test String

Replace

Result:

Matches

No matches found

Capture Groups

No capture groups

Highlighted Matches

Regex Breakdown

Regex Cheat Sheet

Frequently Asked Questions

A regular expression (regex) is a sequence of characters that defines a search pattern. It's used for pattern matching with strings, or string matching, i.e. "find and replace"-like operations.

Regex flags modify how the pattern is matched: g (global match), i (case insensitive), m (multiline), s (dotAll, . matches newlines), u (unicode).

Capture groups are defined with parentheses (). You can reference them with $1, $2, etc. in replacement strings, or access them via the match array.

Greedy matching (*, +) tries to match as much as possible. Lazy matching (*?, +?) tries to match as little as possible by adding a ? quantifier.

Use our quick pattern "Email" to get started. A simple email regex is [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}.