What purpose does the OTP.Li website serve? This is a URL shortener site, it is used for shortening a long URL or website address. For example, w.wiki/U can be used for accessing https://en.wikipedia.org/wiki/URL_shortening, which looks nice when sent via SMS.OTP.Li website is exclusively available to Green Web SMS service users, and they can only use it to shorten long URLs and send them by SMS.