// Change posts per page in the design category add_action( 'pre_get_posts', 'mp_design_cat_posts_per_page' ); function mp_design_cat_posts_per_page( $query ) { if( $query->is_main_query() && is_category( 'design' ) && ! is_admin() ) { $query->set( 'posts_per_page', '12' ); } }

(Código y explicación obtenida de la página: https://amethystwebsitedesign.com/change-the-posts-per-page-in-your-portfolio-category-template/ )