View Word Count Per Post in Your WordPress Admin Posts List

// Add Word Count column to posts list 

function add_word_count_column($columns) {
    $columns['word_count'] = 'Words';
    return $columns;
}
add_filter('manage_posts_columns', 'add_word_count_column');

function populate_word_count_column($column, $post_id) {
    if ($column === 'word_count') {
        $content    = get_post_field('post_content', $post_id);
        $word_count = str_word_count(strip_tags($content));
        echo number_format($word_count);
    }
}
add_action('manage_posts_custom_column', 'populate_word_count_column', 10, 2);

function make_word_count_column_sortable($columns) {
    $columns['word_count'] = 'word_count';
    return $columns;
}
add_filter('manage_edit-post_sortable_columns', 'make_word_count_column_sortable');

function add_word_count_column_style() {
    echo '<style>
        .column-word_count { width:100px;text-align:right!important; }
        .wp-list-table tbody .column-word_count { padding-right:20px!important;color:#666; }
    </style>';
}
add_action('admin_head', 'add_word_count_column_style');

function handle_word_count_sorting($query) {
    if (is_admin() && $query->get('orderby') === 'word_count') {
        $query->set('meta_key', '_word_count');
        $query->set('orderby', 'meta_value_num');
    }
}
add_action('pre_get_posts', 'handle_word_count_sorting');

function update_word_count_on_save($post_id) {
    if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) return;
    if (wp_is_post_revision($post_id))             return;
    if (get_post_type($post_id) !== 'post')        return;

    $count = str_word_count(strip_tags(get_post_field('post_content', $post_id)));
    update_post_meta($post_id, '_word_count', $count);
}
add_action('save_post', 'update_word_count_on_save');