link shortener

 link shortener  is a website that creates a shortlink (typically for any link) for use in space constrained contexts like SMS, Twitter pre-tco and other silos with post length limitations, and have been criticized for worsening link fragility. See also: shortlink.

Silo Examples
See https://en.wikipedia.org/wiki/URL_shortening#Notable_services for a list that does not need to be replicated here (unless there is some IndieWeb-specific use or criticism).