Test, debug, and learn regular expressions with real-time matching and replacement. Perfect for developers, data analysts, and anyone working with text patterns.
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Pre-built patterns for common use cases
Everything you need to know about regular expressions
A regular expression (regex) is a sequence of characters that defines a search pattern. It is used for pattern matching, string validation, and text manipulation.
Flags modify regex behavior: g (global) finds all matches, i (case-insensitive) ignores case, m (multiline) treats ^ and $ as line boundaries, s (dotAll) allows dot to match newlines.
Use parentheses () to create capture groups. In replacements, reference them with $1, $2, etc. In regex, use backslash 1, backslash 2 for backreferences.
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