404 Page/Content Duplicates & its "Warning"

[dhk5018]

My website has MANY duplicate pages and content which are both derived from the MANY 404 pages on my website.  While these are flagged in SEOmoz as "Warnings," should this be of concern to SEO effectiveness?

[Cyrus-Shepard]

Hi Darren,

Sorry, but I'm a bit confused. Technically, both duplicate content and 4xx errors (404s) both qualify as "errors" instead of warnings.

An error is usually considered something that could harm your SEO. For large sites, a few errors wont hurt you much and are to be expected, but these are definitely something you want to address.

Feel free to let us know if you have any questions.

[AdoptionHelp]

Do you mean you have many different pages for 404 errors, as opposed to having many pages that are returning 404?

If you have specialized 404 pages, for whatever reason, you should probably noindex them. That way google isn't  trying to index a page thats just there to help your users find your content, and you're not getting dinged as a site that produces duplicate content.

[josh-riley]

Duplicate content is always a problem is the wrong page is being served up for a search term (i.e, a 404 page vs an active page). It's bad for bounce rate and conversions, and search engines eventually drop 404 pages from their index.

So, as far as SEO effectiveness goes, if people aren't getting served the content you want them to, yes, it's a problem.