Regex Tester & Validator

Matches Twitter retweet markers: the literal 'RT' followed by either the start of a string (\A) or a whitespace character, then an '@' symbol and word characters forming the retweeted username. Useful for detecting or filtering retweets in tweet streams, social media analytics, and mention extraction. Note that JavaScript does not support the \A anchor, so there it matches a literal 'A' instead of string start.