custom 404 error page is to provide the user experience good practice, but in the application process often did not pay attention to the impact on the search engine such as: the wrong server configuration to return "200" status code or a custom 404 error page using the Meta Refresh to return to "302" status code. The right set of custom 404 error page, not only should be able to correctly display, at the same time, should return to the "404" error code, rather than "200" or "302". Although the visit for the user, HTTP status code is "404" or "200", and does not have what difference, but to search engine, this is very important. When the search engine spiders get "404" state in response to a URL request, the URL has learned that failure is no longer the index ", and to the data center feedback will delete the URL said," from the index database of the deletion process may require a long time; and when the search engine "200" state response, is that the URL is effective, it will go to the index, and will be included in the index database, this is the result of the two different URL has different contents: Custom 404 error page content, this leads to problems of "copy. To search engine, especially the noble baby, not only it is difficult to obtain the trust index TrustRank, will greatly reduce the quality of the site assessment of the noble baby.
custom 404 page back improper status codes such as "200" to the site of Shanghai Longfeng effect caused by adverse effects, therefore, to ensure that the custom 404 error page to return to "404" status code is extremely important, but also the website optimization and the basic demand of Shanghai dragon.
often see many websites take the custom 404 error page like this form: first display an error message, and then, through the Meta Refresh page will jump to the website home page, page map or other similar pages. According to the specific implementation in different ways, these 404 pages may return 200 status code, may also return to the "302", but no matter what, Shanghai dragon from a technical point of view, is not a suitable choice. On the "200" state of the situation we have talked about above, then, when the 404 page is returned to the "302", the search engine will be how to treat? Theoretically, the "302" error, the search engine that the page is there, only a temporary change in the address, will still be included in the index this page will appear the same repeat text problem is similar to the "200" state code; secondly, the scope of the mainstream search engine by the noble baby as the representative of the 302 redirect more and more stringent requirements.
HTTP404 of Shanghai dragon
custom 404 error page using Meta Refresh to return 302 status code