How to Create a Custom Search Form with Filters in WordPress

The default WordPress search only checks post titles and content. To give users a better experience, you can build a custom search form that includes filters — such as categories, tags, and custom fields. In this guide, you’ll learn how to create a custom search form, handle the logic in PHP, and display results with filters applied.

Step 1: Create the Search Form

First, create a custom search form that allows users to filter results by category and keyword. You can place this form in your theme (for example, in searchform.php or inside a widget area).

<form role="search" method="get" class="search-form" action="<?php echo esc_url( home_url( '/' ) ); ?>">
  <label>
    <span class="screen-reader-text">Search for:</span>
    <input type="search" class="search-field" placeholder="Search..." value="<?php echo get_search_query(); ?>" name="s">
  </label>

  <!-- Category Filter -->
  <select name="category" class="search-category">
    <option value="">All Categories</option>
    <?php
    $categories = get_categories( array( 'hide_empty' => false ) );
    foreach ( $categories as $cat ) :
      $selected = ( isset( $_GET['category'] ) && $_GET['category'] == $cat->term_id ) ? 'selected' : '';
      echo '<option value="' . esc_attr( $cat->term_id ) . '" ' . $selected . '>' . esc_html( $cat->name ) . '</option>';
    endforeach;
    ?>
  </select>

  <!-- Submit Button -->
  <button type="submit" class="search-submit">Search</button>
</form>

This form submits to your site’s default search URL (e.g., ?s=keyword&category=3), which you’ll process next.

Step 2: Modify the Query with pre_get_posts

Now, use the pre_get_posts action to modify the main query and filter results based on user input. Add this to your functions.php file.

<?php
// Customize search query with category filter
add_action( 'pre_get_posts', function ( $query ) {
    if ( $query->is_search() && $query->is_main_query() && ! is_admin() ) {

        // Category filter
        if ( ! empty( $_GET['category'] ) ) {
            $category_id = (int) $_GET['category'];
            $query->set( 'cat', $category_id );
        }

        // Optional: limit to specific post type
        $query->set( 'post_type', 'post' );

        // Optional: order results
        $query->set( 'orderby', 'date' );
        $query->set( 'order', 'DESC' );
    }
});

This ensures the search results only show posts in the selected category (if one is chosen).

Step 3: Add a Custom Field Filter (Optional)

If your site uses custom fields (meta data), you can filter by those too. Let’s add a dropdown for a custom field called difficulty with values “Beginner,” “Intermediate,” and “Advanced.”

Update the Search Form

<select name="difficulty" class="search-difficulty">
  <option value="">All Levels</option>
  <option value="beginner" <?php selected( $_GET['difficulty'] ?? '', 'beginner' ); ?>>Beginner</option>
  <option value="intermediate" <?php selected( $_GET['difficulty'] ?? '', 'intermediate' ); ?>>Intermediate</option>
  <option value="advanced" <?php selected( $_GET['difficulty'] ?? '', 'advanced' ); ?>>Advanced</option>
</select>

Update the Query Logic

<?php
add_action( 'pre_get_posts', function ( $query ) {
    if ( $query->is_search() && $query->is_main_query() && ! is_admin() ) {

        // Filter by category
        if ( ! empty( $_GET['category'] ) ) {
            $query->set( 'cat', (int) $_GET['category'] );
        }

        // Filter by custom field 'difficulty'
        if ( ! empty( $_GET['difficulty'] ) ) {
            $meta_query = array(
                array(
                    'key'     => 'difficulty',
                    'value'   => sanitize_text_field( $_GET['difficulty'] ),
                    'compare' => '=',
                ),
            );
            $query->set( 'meta_query', $meta_query );
        }
    }
});

Step 4: Customize the Search Results Page

Edit your search.php or archive-search.php template to display selected filters and the corresponding results.

<?php get_header(); ?>

<h1>Search Results</h1>

<?php if ( have_posts() ) : ?>
  <?php while ( have_posts() ) : the_post(); ?>
    <article>
      <h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
      <p><?php the_excerpt(); ?></p>
    </article>
  <?php endwhile; ?>

  <?php the_posts_pagination(); ?>
<?php else : ?>
  <p>No results found. Try adjusting your filters.</p>
<?php endif; ?>

<?php get_footer(); ?>

Step 5: Display Active Filters

To make it clear which filters are active, you can display the current selections above the results:

<div class="search-summary">
  <strong>Keyword:</strong> <?php echo esc_html( get_search_query() ?: 'None' ); ?><br>
  <strong>Category:</strong> <?php
    if ( ! empty( $_GET['category'] ) ) {
      $cat = get_category( (int) $_GET['category'] );
      echo esc_html( $cat->name );
    } else {
      echo 'All';
    }
  ?><br>
  <strong>Difficulty:</strong> <?php echo esc_html( $_GET['difficulty'] ?? 'All' ); ?>
</div>

Step 6: Style Your Search Form and Results

Add CSS to your theme’s style.css for better presentation:

.search-form {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.search-field,
.search-category,
.search-difficulty {
  padding: 6px 10px;
  font-size: 16px;
}

.search-submit {
  background: #0073aa;
  color: #fff;
  border: none;
  padding: 8px 14px;
  cursor: pointer;
}

.search-submit:hover {
  background: #005b8c;
}

Optional Enhancements

• AJAX filtering: Load search results dynamically without reloading the page.
• Multiple taxonomies: Allow filtering by both categories and tags.
• Range filters: Add number or date filters using meta_query comparisons (e.g., price or date range).
• Save user filters: Use cookies or sessions to remember selections.

Conclusion

Creating a custom search form with filters in WordPress helps users find content faster and improves UX. By customizing pre_get_posts and adding category or custom field filters, you can build powerful, precise search functionality — all without relying on plugins.

Give users control. Make search intuitive.

🎨 Want to learn more? Visit our WordPress Customization Hub for tips and advanced techniques.