Update for WooCommerce 3+
The hook wc_add_to_cart_message is deprecated and replaced by wc_add_to_cart_message_html. You can use the following (compact effective way):
add_filter( 'wc_add_to_cart_message_html', '__return_false' );
Or the normal way:
add_filter( 'wc_add_to_cart_message_html', 'empty_wc_add_to_cart_message');
function empty_wc_add_to_cart_message( $message, $products ) {
return '';
};
Before WooCommerce 3, use this:
Removing only the message (pasting it to your function.php file inside your active child theme or theme). This function will return an empty message:
add_filter( 'wc_add_to_cart_message', 'empty_wc_add_to_cart_message', 10, 2 );
function empty_wc_add_to_cart_message( $message, $product_id ) {
return '';
};
Code goes in function.php file of your active child theme (or active theme).
Note: wc_add_to_cart_message replace deprecated hook woocommerce_add_to_cart_message.
CSS: Removing top message box on checkout page (add this css rule to the style.css file located inside your active child theme or theme):
.woocommerce-checkout .woocommerce .woocommerce-message {
display:none !important;
}