Should there be a canonical tag on my 404 error page?

[Leighm]

In my crawl diagnostics, I notice some 4xx client errors. They are appearing for pages that no longer exist, so I'm not sure what the problem is. Shouldn't they just be dealt as 404's?

Anyway, on closer inspection I noticed that my 404 error page contains a canonical tag which points to the missing page. Could this be the issue? Is it a good idea to remove the canonical tag from this error page?

Thanks.

[magicrob]

Discovering 404s can be useful.

Is the old page deleted? Why not 301 redirect the URL to an appropriate page elsewhere on your site? Tools such as Screaming Frog's SEO Spider can crawl your website and help you discover 404s. By redirecting the page with a permanent redirect search engines will to pass any link juice the previous page had to the new page. Redirecting will also cleanup your pages in the SERPs and help with any broken internal links on your site (though it'd be better to fix those).

There's no need to having a rel=canonical tag on a 404 page (but if you do, ensure the tag is for the page itself and not actual content on your site).

There's also no need for search engines to index your 404 page, so I suggest adding the meta NOINDEX tag to the page.

[wildnerakademie]

The canonical tag on errorpages make no sense! For gone webpages just setup a 301 redirect in the .htaccess. And make use of the Google webmaster tools to identify waht Google sees.

[Marvo]

If the old pages are NOINDEX, are the old inbound links still passed on to the new page via the 301's. and is the google juice passed?  I've wanted to do exactly what you suggest, but was afraid of severing the Linking credit from those old inbounds.

[firstconversion]

1 there is no point having canonical on a 404 page. I would say its a very confusing signal to bots

2 don't always 301. 404 exists for a reason. In most cases I will 301 old pages but there are cases where letting pages 404 is the correct way forward

[ajmihalic4]

I repeated this elsewhere, but I think canonical on 404 page does make sense, especially if you consider the following two statements true:

1. There is a reason for 404s, don't 301 everything
2. There is no reason to lose the value of someone linking to your page.

If those 2 statements are true then you should create an individual error page, and then everytime you serve a 404 you should include canonical to that error page. That page should have useful content (explanation of page missing and where you could go), probably a search box, and links to the most valuable content on your site. This satisfies both points.