Crawl errors in GWT!

[inhouseseo]

I have been seeing a large number of access denied and not found crawl errors. I have since fixed the issued causing these errors; however, I am still seeing the in webmaster tools.

At first I thought the data was outdated, but the data is tracked on a daily basis!

Does anyone have experience with this? Does GWT really re-crawl all those pages/links everyday to see if the errors still exist?

Thanks in advance for any help/advice.

[inhouseseo]

BTW, the crawls stats show Google crawling about 3-10K pages a day. The daily errors are numbering over 100K. Is this even possible? How can if find so many errors if the spiders are not even crawling that many pages?

Thanks again!

[rtmlwise]

Crawl errors are also due to links of those pages on other sites or in google's own index. When Google revisits those pages and does not find them, they flag off as 404 errors.

[RuthBurrReedy]

Neither access denied nor not found crawl errors are dealbreakers as far as Google is concerned. A not found error usually just means you have links pointing to pages that don't exist (this is how you can be receiving more errors than pages crawled - a not found error means that a link to that page was crawled, but since there's no page there, no page was crawled).  Access denied is usually caused by either requiring a login or blocking the search bots with robots.txt.

If the links causing 404 errors aren't on your site it's certainly possible that errors would still be appearing.  One thing you can do is double-check your 404 page to make sure it really is returning an error of 404: not found at the URL level.  One common thing I've seen all over the place is that sites will institute a 302 redirect to one 404 page (like www.example.com/notfound).  Because the actual URL isn't returning a 404, bots will sometimes just keep crawling those links over and over again.

Google doesn't necessarily crawl everything every day or update everything every day.  If your traffic isn't being affected by these errors I would just try as best you can to minimize them, and otherwise not worry too much ab out it.