Sort WordPress posts by title

• Log into WordPress
• Click on Appearance -> Theme Editor
• Add the following code at the end of functions.php to sort posts by title instead of date, for categories and tags.

/**
 * Sort posts by title instead of date for categories and tags.
 */
function sort_posts_by_title($query)
{
    if (is_category() || is_tag()) {
        $query->set('orderby', 'title');
        $query->set('order', 'ASC');
    }
}
add_action('pre_get_posts', 'sort_posts_by_title');