Enabling Shortlinks
Find out how to enable/disable shortlinks

Shortlinks Settings
Shortlinks turns a long URL into a shorter version.
If you share text on a social network such as Twitter, you can save a few characters by shortening your URLs.
Shortlinks Require a Third-Party Service
Highlight and Share does not provide native URL shortening. You'll need a shortlink plugin enabled, and Highlight and Share will try to use the shortlink from the third-party service.
For shortlink services, it is recommended to use Jetpack or Bitly.

Shortlink Example using Jetpack Shortlinks

WP.me Shortlinks
Jetpack
Jetpack Offers Native Shortlinks

Bitly's WordPress Plugin
WordPress.org
Bitly Allows for Shortlinks and Tracking