How to improve search on a WordPress site

Before changing anything, search for a title you know exists, a phrase from the body, a page, a custom post type, a taxonomy term, and a likely misspelling. Also test an empty search and a term that should return no results.

Write down what is missing. This separates a broken search form from a weak index or a poor results layout. Test again after each change, because changing the query can make unrelated content appear in results.

Your search form should submit with the GET method, send the visitor's text in a field named s, and point to the site's home URL. In a classic theme, WordPress looks for searchform.php; in a block theme, use the Search block. WordPress documents both routes.

Check the form in the browser, not just in the editor. A nested form, a missing s field, or a custom JavaScript search box that submits a different parameter can make the search appear to work while returning the wrong query.

Native WordPress search uses the main WP_Query. Its default post type is posts, so pages and custom post types may not appear unless you include them deliberately. Use the pre_get_posts action to alter the main search query, and limit the change with checks for the main query and search requests.

Do not use query_posts() to replace the search loop. WordPress recommends modifying the existing main query instead, because replacing it can damage pagination, conditions, and performance.

Make sure the theme has a search results template, usually search.php in a classic theme, and that it displays the result title, a useful excerpt, the content type, and a clear no-results message. Keep the search term visible so visitors can correct it without guessing what was searched.

Native WordPress search mainly matches post titles and content. It does not automatically search important data stored in custom fields, such as product references, author names, specifications, or page-builder fields. If that information matters, include it in the visible content manually or use an index-based search tool.

Review your analytics or server logs for searches that return no results, then add missing content, synonyms, redirects, or better labels. Pay special attention to product codes, abbreviations, singular and plural terms, and words visitors use that differ from your site's wording.

Also check performance on larger sites. A search query that scans many post types or custom fields can become slow, and rebuilding a large search index during busy hours can put pressure on the database. Schedule maintenance for a quiet period and test the results page while logged out.

For a site where native search is not enough, install Relevanssi Premium from Plugins > Add New Plugin > Upload Plugin, activate it, choose the post types, taxonomies, and custom fields to index, save the settings, and build the index. Its settings cover matching, relevance ranking, snippets, and search scope.

Use the custom-field settings selectively rather than indexing every internal field, then rebuild and test with real visitor queries. Relevanssi Premium can index PDF content and use it in searches, and it supports typo-tolerant suggestions and relevance controls. Instant results as visitors type are documented as a separate Relevanssi Live Ajax Search companion, so confirm that requirement before promising live search.