Mindshare Labs, Inc.

<p>A highly customizable AJAX-based WordPress search bar alternative with the ability to autocomplete <a href="http://en.wikipedia.org/wiki/Faceted_search" rel="nofollow ugc">faceted search queries</a>. Users can quickly and dynamically browse through your site’s taxonomies and post metadata to find exactly what they’re looking for, and results can be loaded beneath the search bar instantly.</p>
<h4>Features</h4>
<ul>
<li>Searches post title and body content</li>
<li>Can search by multiple keywords, and by full phrases</li>
<li>Highlights search terms in results</li>
<li>Option to send search queries as events to your Google Analytics account</li>
<li>Facets by post category</li>
<li>Can search in multiple categories (OR or AND search)</li>
<li>Category options are dynamically generated and autocompleted as you type</li>
<li>Attractive and lightweight interface based on jQuery, Backbone.js, and the VisualSearch.js library</li>
<li>Customizable results template using standard WordPress functions</li>
<li>Search through an unlimited number of user-specified taxonomies and meta fields (including data contained in Advanced Custom Fields).</li>
<li>Conduct radius searches against data stored in the ACF Map field (i.e. search for posts within x km of a user-specified location).</li>
</ul>


WP Ultimate Search

Powerful AJAX-based search alternative which supports faceting queries by taxonomies, terms, location, and post metadata.

meloniq

<p>Enables searching post meta fields on admin pages.</p>


WP-Admin Search Post Meta

Enables searching post meta fields on admin pages.

WP Ultimate Search vs WP-Admin Search Post Meta