Scott (@scottsweb)

Add Google style instant search and search suggest to your WordPress powered site. This plugin will begin displaying search results as soon as your site visitor starts typing into the search box.
The plugin requires very little configuration and should work out of the box with most themes. The plugin has its own options page to configure the plugin to work with your theme if you require it.
<a href="http://scott.ee/" title="WordPress designer and developer" rel="nofollow ugc">a plugin by Scott Evans</a>

Instant Search & Suggest

Instant WordPress search with search suggestions for tags, categories and titles.

Renat Galyamov

Improve your site SEO and performance. More info on <a href="https://renatello.com/instant-seo/" rel="nofollow ugc">https://renatello.com/instant-seo/</a>.

Instant Search & Suggest vs Instant Performance & SEO