My question is about multiple aspects of serving a 404, while this question is only about an url.
I see in the web multiple methods to serve a 404 in case a page becomes no longer working/found - but I'm confused about the right way.
Case
There is a working page https://example.com/working-page.html, which suddenly becomes unfound.
Method 1
After becoming unfound, the page maintains its original URL, content and meta, but changes its status code from 200 to 404, which is visible only in the header, like this:
Method 2
The page which is now unfound, maintains its original url, but changes
status code, in the header from 200 to 404,
content and meta - from original to those specific for page 404, something like
Page not found (404)
Method 3
The page which is now unfound, changes everthing:
- URL, from https://example.com/working-page.html to https://example.com/404.html,
- Content, from original to those specific for page 404,
- Meta, from original to those specific for page 404, as in the method 2,
- Status code, from 200 to 404
Q: Which method would you consider as the best practice?