On Twitter, Google’s John Mueller confirmed that your website should not have pages that deliver a 5xx status code. 5xx status codes indicate server errors. If your web pages deliver such a status code to search engines, search engines will think that your website is broken, even if the page can be displayed in your web browser.
Avoid 5xx status codes and show 404 for invalid URLs
In general, you should aim to avoid having URLs that trigger server errors (5xx result codes) — regardless of where they come from. If URLs are invalid for your site, you should return 404 so that it's clear that they're not valid for your site.— 🍌 John 🍌 (@JohnMu) 17. März 2019
John Mueller also said that Google will visit URLs as long as there are external links that point to that URL, even if the URL delivers a 404 HTTP status code:
As long as we have signals for that URL (even if it's just a random link somewhere), we'll keep trying it from time to time.— 🍌 John 🍌 (@JohnMu) 17. März 2019
For that reason, it’s a good idea to redirect your old URLs to new pages on your website.
How to check the HTTP status codes on your website
HTTP status codes are invisible. Your web browser can show the correct page while sending an error code behind the scenes. There is something wrong with your web pages if they do not deliver a “200 OK” HTTP status code.
The website audit tool in SEOprofiler checks the HTTP status codes of your web pages so that you can fix errors quickly and easily:
In addition to this, the website audit tool checks your pages for any other things that influence the position of your web pages on the search results pages of Google and other search engines.
Check your pages now
Create your SEOprofiler account now to get a website audit report for your own website: