RegEx Tester — Match & Highlight Text Online

What is a Regular Expression?

A regular expression (shortened as Regex or Regexp) is a sequence of characters that specifies a search pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. Tools for evaluating regular expressions are incredibly common among programmers.

Common RegEx Flags:

• g (global): Don't return after the first match. Find all matches instead.
• m (multi-line): The ^ and $ anchors match the start and end of a line, instead of just the whole string.
• i (insensitive): Case insensitive match (ignores case of [a-zA-Z]).