URL shortener

 URL shortener  is a service that turns a typical longer URL, like a permalink, into a much shorter URL, typically using a short domain, often per-site both for some silos, and several indieweb sites.

Why

 * URL shorteners help you make better use of limited characters in editing tools where you would like to share a link but are restricted by a character count.

Criticism

 * If you use an external URL shortener, you are beholden to their service being active and working. If the URL shortener becomes inactive, existing URLs created may be broken.
 * "Aside from search engines, I can’t think of any other type of website that could disable so many links on so much of the internet in one fell swoop than a URL shortening service." urlTea now tr.im, this stuff is scary

Libraries
Open source libraries and implementations to run your own URL shortener:


 * Yourls: requires Apache with PHP and MySQL