My website is set up in such a way such that any rubbish URL (e.g.
example.com/asdfgh) will get a blank page and not a 404 error. I am not sure if its bad or good for SEO. Could you let me know what do you think about this.
This is only reaction on this topic that I found on net:
This is not an error, there exists unlimited URLs for any canonical URL. Because when you add something to a valid URL, it is just handled as parameter. When the parameter is not used within the view, then the parameter is not without any effect => "unlimited" valid URLs and that is not an error, that is by design. Search engines handle that completely correctly. 404 is actually a code for an not valid link, but our job is to assure that there are no non valid links. Remind the old times, when you wrote a page with static HTML, and you used a link to a non-existing file, for that you have the 404. But in a CMS, you always open the
/index.php, which is always valid. So even our simulation of 404 is nonsense, it should be 303 or so, actually.