Regex Tester & Validator

Matches sed-style substitution commands like s/pattern/replacement, starting with an uppercase or lowercase 's'. The pattern and replacement parts are each limited to 1-64 non-slash characters, and the expression must end with a non-space character, which typically captures the closing slash or flags such as 'g'. Useful for detecting or extracting find-and-replace instructions from chat messages, editor commands, or logs.