Non-existent page returns code 200

Question

I have a page like mysite.com/contacts/ If I enter non-existent urls like:

mysite.com/contacts--/
mysite.com/contacts%20/

i get status 200 and the page opens mysite.com/contacts/ although if I enter:

mysite.com/contacts1/

As expected, I am getting a 404 error.

How can I implement error handling at the CMS level so that non-existent pages return a page with a 404 error template? There may be some plugin that implements URL management?

Answer 1

That's not what's happening, when you visit /contacts--/ it doesn't return a 200 code, but instead it returns a 301 redirect code. The browser then follows this redirect and heads to /contact and it's /contact that returns 200 code.

This is because /contact is the canonical URL of that page, and WordPress redirects to canonical pages out of the box for improved SEO. It should also be adding a meta tag to the header containing the canonical URL to avoid duplicate content penalties.

Answer 2

If you need to prevent WordPress from guessing URLs, you can add the following code to function.php

function remove_redirect_guess_404_permalink( $redirect_url ) {
  if ( is_404() ) {
    return false;
  } //end if
  return $redirect_url;
} //end remove_redirect_guess_404_permalink()
add_filter( 'redirect_canonical', 'remove_redirect_guess_404_permalink' );

Link to article