Test regular expressions with live highlighting, match groups, and a library of common patterns.
A regular expression (regex) is a sequence of characters that defines a search pattern. Regexes are used in programming for string matching, validation, search-and-replace, and data extraction.
g = global (find all matches), i = case-insensitive, m = multiline (^ and $ match line boundaries), s = dotAll (. matches newlines), u = unicode.