How to remove or disable rel shortlink url with post id in http response header for wordpress 5+ and and below, without a plugin?

Question

When you inspect your blog post in the Network tab of your Chrome browser, it looks like below:

Response Headers
cache-control: no-cache, no-store, must-revalidate
.....
.....
.....
link:<https://demo.com/?p=53>; rel=shortlink
server:Apache
.....
status:200
vary:Accept-Encoding
.....
.....

This exposes your blog post id

Answer 1

All you need to do is as below in your functions.php file

add_filter('after_setup_theme', 'my_disable_rel_shortlink');

function my_disable_rel_shortlink() { remove_action( 'template_redirect', 'wp_shortlink_header', 11); }