Add this code to your themes or functions.php
<?php // Creating the widget class wpb_widget extends WP_Widget { function __construct() { parent::__construct( // Base ID of your widget 'wpb_widget', // Widget name will appear in UI __('Simple Widget', 'wpb_widget_domain'), // Widget description array( 'description' => __( 'Simple widget', 'wpb_widget_domain' ), ) ); } // Creating widget front-end // This is where the action happens public function widget( $args, $instance ) { $title = apply_filters( 'widget_title', $instance['title'] ); // before and after widget arguments are defined by themes echo $args['before_widget']; if ( ! empty( $title ) ) echo $args['before_title'] . $title . $args['after_title']; // This is where you run the code and display the output echo __( 'Hello, World!', 'wpb_widget_domain' ); echo $args['after_widget']; } // Widget Backend public function form( $instance ) { if ( isset( $instance[ 'title' ] ) ) { $title = $instance[ 'title' ]; } else { $title = __( 'New title', 'wpb_widget_domain' ); } // Widget admin form ?> <p> <label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label> <input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>" /> </p> <?php } // Updating widget replacing old instances with new public function update( $new_instance, $old_instance ) { $instance = array(); $instance['title'] = ( ! empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : ''; return $instance; } } // Class wpb_widget ends here // Register and load the widget function wpb_load_widget() { register_widget( 'wpb_widget' ); } add_action( 'widgets_init', 'wpb_load_widget' );