Relevanssi – A Better Search的作者是Mikko Saari，目前有100,000+个有效安装。已经Tested with 5.4.1版本的wordpress。
Relevanssi replaces the standard WordPress search with a better search engine, with lots of features and configurable options. You’ll get better results, better presentation of results – your users will thank you.
This is the free version of Relevanssi. There’s also Relevanssi Premium, which has added features. For more information about Premium, see Relevanssi.com.
Do note that using Relevanssi may require large amounts (hundreds of megabytes) of database space (for a reasonable estimate, multiply the size of your wp_posts database table by three). If your hosting setup has a limited amount of space for database tables, using Relevanssi may cause problems. In those cases use of Relevanssi cannot be recommended.
Search results sorted in the order of relevance, not by date.
Fuzzy matching: match partial words, if complete words don’t match.
Find documents matching either just one search term (OR query) or require all words to appear (AND query).
Search for phrases with quotes, for example “search phrase”.
Create custom excerpts that show where the hit was made, with the search terms highlighted.
Highlight search terms in the documents when user clicks through search results.
Search comments, tags, categories and custom fields.
Adjust the weighting for titles, tags and comments.
Log queries, show most popular queries and recent queries with no hits.
Restrict searches to categories and tags using a hidden variable or plugin settings.
Index custom post types and custom taxonomies.
Index the contents of shortcodes.
Google-style “Did you mean?” suggestions based on successful user searches.
Support for WPML multi-language plugin and Polylang.
Support for s2member membership plugin, Members, Groups, Simple Membership and other membership plugins.
Advanced filtering to help hacking the search results the way you want.
Search result throttling to improve performance on large databases.
Disable indexing of post content and post titles with a simple filter hook.
Premium features (only in Relevanssi Premium)
Indexing attachment content (PDF, Office, Open Office).
Improved spelling correction in “Did you mean?” suggestions.
Searching across multiple sites in the same multisite installation.
Search and index user profiles.
Search and index taxonomy term pages (categories, tags, custom taxonomies).
Search and index arbitrary columns in wp_posts MySQL table.
Assign weights to any post types and taxonomies.
Assign extra weight to new posts.
Let the user choose between AND and OR searches, use + and – operator (AND and NOT).
Export and import settings.
WP CLI commands.
Redirects for searches.
Relevanssi in Facebook
You can find Relevanssi in Facebook.
Cristian Damm for tag indexing, comment indexing, post/page exclusion and general helpfulness.
Marcus Dalgren for UTF-8 fixing.
Warren Tape for 2.5.5 fixes.
Mohib Ebrahim for relentless bug hunting.
John Calahan for extensive 4.0 beta testing.