WordPress is a flexible content management system, but its default site search doesn’t support taxonomies, custom post types, or custom fields. Fortunately, there are a variety of plugins available to extend a site’s search capabilities on WordPress.
Here is a list of plugins to improve the internal search on your WordPress site, to include custom post types and fields, taxonomies, live search, heatmaps on results, and more. Most of the plugins are free, though several have premium versions as well for advanced features.