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.

Dan Poulton

This very simple plugin generates a Bitly shortlink and saves it to your WordPress database.
It does this via two different methods:
<ul>
<li>Publish a page or post for the first time</li>
<li>Click the generate all button</li>
</ul>
<a href="https://dan-p.net/wordpress-plugins/danp-bitly-urls" rel="nofollow ugc">Getting Started Guide</a>

DanP Bitly URLs

Generate Bitly short links for posts and pages every time you first publish. Already have posts? You can generate a link for all posts and pages too.

Bit.ly Shortlinks Multisite (Uses OAuth 2 API) vs DanP Bitly URLs