A 404 error is your site sending someone to your sitemap because the URL that they entered does not exist.
Steps to finding 404 Errors In Webmaster Tools
- Log into Webmaster Tools
- Under the Health menu in the left hand navigation, click on Crawl Errors
- Under the Text URL Errors click on the "Not Found" box
- You will then be presented with a list of URLs that are not found by Google and therefore resulting in a "404 error". To download a list, click the download button.
Steps to find 404 pages on your site:
- Log onto your Google Webmaster tools
- On the right side go to Crawl
- On the right side click Crawl Errors
- You will see a graph on the different errors that Google has found
- Right underneath there is a list of your 404's
- To get a full list of those 404's to create redirects, click on the Download button
- Select CSV file
Why do I have 404 errors? Some reasons that you may get 404 errors in your Webmaster Tools are...
- A customer mis-typed a URL
- A customer has bookmarked an old site page that you deleted and did not properly re-direct
- A product has been discontinued, so the URL is no longer active
- A search engine has an old page indexed that was not properly re-directed
How To Fix/Prevent 404 Errors
As you may have gathered by now, the main reason for 404 errors is that someone, or Google, is trying to access a page that no longer exists. While Google has said that these error do not effect your search engine rankings, it could be frustrating to a user/customer that is trying to get to a page on your site that is no longer available.
- If you are trying to "fix" 404 errors, use the above Webmaster Tools instructions to get a list of pages that are trying to be found. Then use the re-direct feature in WSM to easily send that traffic to the correct page.
- If you are trying to prevent 404 errors, make sure that when you delete a page, news article, product, brand, etc., you re-direct the deleted URL to the appropriate page where that information can be found.
Google's guide in what to do with deleted pages:
"When you remove a page from your site, think about whether that content is moving somewhere else, or whether you no longer plan to have that type of content on your site. If you’re moving that content to a new URL, you should 301 redirect the old URL to the new URL—that way when users come to the old URL looking for that content, they’ll be automatically redirected to something relevant to what they were looking for. If you’re getting rid of that content entirely and don’t have anything on your site that would fill the same user need, then the old URL should return a 404 or 410. Currently Google treats 410s (Gone) the same as 404s (Not found). "