Load Contact Form 7 only on Contact Page

/*This goes in wp-config.php*/

define('WPCF7_LOAD_JS', false); // Remove CF7 JavaScript
define('WPCF7_LOAD_CSS', false); // Remove CF7 CSS

/*This goes in function.php*/

/* Contact Form 7 nur auf Kontakt Seite laden */
add_filter( 'wpcf7_load_js', '__return_false' ); // Disable CF7 JavaScript
add_filter( 'wpcf7_load_css', '__return_false' ); // Disable CF7 CSS

add_action('wp_enqueue_scripts', 'load_wpcf7_scripts');
function load_wpcf7_scripts() {
    if ( is_page('contact') ) {
        if ( function_exists( 'wpcf7_enqueue_scripts' ) ) {
            wpcf7_enqueue_scripts();
        }
        if ( function_exists( 'wpcf7_enqueue_styles' ) ) {
            wpcf7_enqueue_styles();
        }
    }
}

/*
Tip
You can also using page ID and even page name instead of page
slug as the condition to match the page.
Refer to is_page() documentation for possible usage.

Note
If you have multiple pages with CF7’s contact forms, you can use PHP or operator, ||,
or use the array for is_page() function as the condition. For example:

is_page( array( ‘contact’ , ‘feedback’ , ‘survey’ ) )*/