Denis Lam

WordPress generates shortlinks for your posts and pages. By default it uses the <code>?p=</code> with the post ID added to it, but if you have a rather long domain name this isn’t very useful. If you use <a href="http://bit.ly" rel="nofollow ugc">Bit.ly</a>, this plugin will help you replace the shortlink WordPress generates with a proper Bit.ly shortlink.
This plugin uses the latest Bit.ly OAuth 2 draft specification API instead of its deprecated V3 API and enables you to use generic access token to automatically enable Bit.ly shortlinks in your entire multisite network without the need for each site user to have to tinker with any settings or authentication configurations.

Bit.ly Shortlinks Multisite (Uses OAuth 2 API)

This plugin replaces the default WordPress shortlinks with Bit.ly shortlinks for your single site or multisite WordPress network.

edwardrpool

This plugin is ultra lightweight. It adds a media button above the tinyMCE editor on both the page and post editor, which when pressed copies a shortlink to your clipboard.
The idea behind this plugin is to add short-linking capabilities, without all the bloated code found in other plugins. This plugin does not alter the database, nor is any data saved or collected. It uses the built in WordPresspost/page ID’s in the URL.

ERP ShortLinks

A very lightweight plugin which adds a shortlink button to the post/page editor for quickly sharing on social platforms.

Bit.ly Shortlinks Multisite (Uses OAuth 2 API) vs ERP ShortLinks