The default WordPress “shortlink” URLs look like this: <code>http://www.example.com/blog/?p=123</code>, where “<code>123</code>” is actually a 7+ digit decimal number. This plugin shrinks your shortlinks by encoding that number into only 4 characters, and using the abbreviated URL prefix of your choice.
On my site, the default shortlinks are 35 bytes long, even though I have a very short domain name. This plugin shrinks them to 21 total bytes, which is comparable to most public URL-shortener services, and better than many.
E.g., this: <code>http://www.jwz.org/blog/?p=13240780</code> 
becomes: <code>http://jwz.org/b/ygnM</code>
This doesn’t affect your (long) permalinks: those can still be in whatever format you like.

Base64 Shortlinks

This plugin makes your shortlinks shorter!

ggriesser

Keep your site simple and lean! Slim WordPress by <a href="https://www.velocious.io/" title="Velocious.io" rel="nofollow ugc">Velocious.io</a> helps you to speed up your site by disabling and removing unnecessary WordPress features.
WordPress does not care if you use emoticons or embeds – the corresponding script is loaded on every page regardless if emojis are visible or not.
With Smart WP you are getting back control over these features and you can speed up your WordPress site.
Decide on your own which features are loaded and which are not!
Your users will love it!
By using Slim WordPress you can:
<ul>
<li>Disable emoticons</li>
<li>Disable embeds</li>
<li>Remove shortlinks</li>
<li>Remove WordPress’ version number</li>
</ul>

Slim WordPress

Send your site on a diet and remove unnecessary WordPress features!

Base64 Shortlinks vs Slim WordPress