n3k4

It is a common SEO technique to remove ‘stop words’ from the slug URL that are considered low priority in the search algorithm. Also, it helps trim the maximum URL length by creating a summary of the post title rather than the full text.
This plugin will remove the stop words from the URL from a defined list you can edit in the options.
A list of predefined stop words are included with the plugin and also available <a href="http://kaneandre.ws/wp-content/uploads/stop-words.txt" rel="nofollow ugc">here</a>.

Remove Stop Words

Remove stop words from the slug URL in your permalinks for search engine optimization.

antithesisgr

This plugin allows you to use longer URLs (permalinks), by allowing much more characters in your titles and slug. The important is that this is done in a way that is future compatible with WordPress core updates. 
There is a 200 characters limitation on WordPress core nowadays and this limit is raised to 3000 with the plugin. 
Plugin is always extending the current WordPress core code – your long URLs will work even after WordPress core updates. 
This plugin is really useful especially in non-latin slugs because of the required url escaping that increases the length of your permalinks a lot.
<h4>Features</h4>
<ul>
<li>Upon activation the available slug length (post title) will become 3000, allowing long permalinks.</li>
<li>Required functionality is automatically applied without changing WordPress core files.</li>
<li>Even after core updates, plugin will automatically apply required changes and just keep your long URLs working.</li>
<li>Plugin requires at least MySQL 5.0.3</li>
</ul>

Longer Permalinks

Excellent plugin

Allow long permalinks in your WordPress. Useful especially for using non-latin characters in permalinks.  Respects future relevant core updates.

Remove Stop Words vs Longer Permalinks