Do 404 Errors hurt SEO ?

[RagingBull]

I recently did a crawl test and it listed over 10,000 pages, but around 282 of them generated 404 errors (bad links)

I'm wondering how much this hurts overall SEO and if its something I should focus on fixing asap ?

Thanks.

[Hakkasan]

As Alan said, you have a ton of old 404 pages with no one linking to them and they're not being indexed in the SERPs, just let them 404 because that's what Google recommends to get rid of them. If you are getting links and traffic for your 404's pages, you definitely want to make it a priority to 301 redirect them. The grunt work is looking at each URL and determining its value.

Two best responses on this issue that I have found so far.

From the Google Webmaster Central Blog: http://googlewebmastercentral.blogspot.com/search?q=%22404+week%22

Rand Fishkin himself: http://www.seomoz.orgwww.seomoz.org/blog/are-404-pages-always-bad-for-seo

[AlanMosley]

One other point, if you had external links pointing to the missing links, you should 301 then to a relevant page

[RagingBull]

Just what I was looking for!

Thanks!

[AlanMosley]

Yes and no. having a 404 that the SE finds is not going to hurt you, it will eventualy remove it from its index, but if you have a broken link pointing to a 404 then yes you are leaking PR. Seeing you did a scan, that usely follow links, i think you must have the later.