Google has released a new help document that explains how different HTTP status codes affect the way websites are displayed in search results.
A recent tweet indicated that Gary Illyes of Google was involved in the production of this document.
This is a new guide for when you’re not sure how a particular status code affects SEO. Let’s take a look at what’s included in Google’s new guidelines for site owners and developers.
You may already know this, but it’s okay to update your knowledge of the status code with the latest available information.
How HTTP status codes affect Google Search
The new Google document covers the top 20 status codes and the most important DNS and network errors found by Googlebot on the web.
When a browser or crawler requests content, the server hosting the site generates an HTTP status code.
For example, if the content requested by the browser is no longer hosted on the server, a 404 (Not Found) status code will be generated.
The first number in the status code indicates which category it belongs to.
All 2xx codes indicate successful crawling, all 3xx codes indicate redirection, etc.
Instead of browsing the 20 status codes, I collected the key points of each category.
HTTP 2xx (success)
These codes mean that Googlebot can crawl content and pass it to the indexing pipeline.
Google emphasizes that the 2xx HTTP status code does not guarantee indexing, it just means that no errors were found.
The exception is the 204 status code, which means that the page was successfully accessed but nothing was found.
For pages that provide a 204 code, Google can display a soft 404 in Search Console.
HTTP 3xx (redirects)
Not all redirects are the same.
The HTTP 301 status code sends a stronger signal than the 302, 303, or 307 code, in terms of which URL should be considered the canonical.
The 304 status code tells Google that the content is the same as when it was last crawled.
It has no effect on the index, but will cause the url tag to be recalculated.
What happens if the redirect doesn’t work?
Until you stop trying, Googlebot can track up to 10 redirect hops.
If content is not received within 10 hops, Search Console will display a redirect error in the site index coverage report.
HTTP 4xx (client errors)
Pages displaying 4xx status codes are not considered for indexing in Google search results.
All 4xx errors except 429 are treated the same. They indicate to Googlebot that the content does not exist.
If the content previously existed, the URL will be removed from the Google search index.
The 429 status code means that Googlebot cannot access the URL because the server is overloaded.
These URLs will remain in the Google index.
HTTP 5xx (server errors)
A 5xx server error caused Googlebot to temporarily slow down when crawling.
If previously indexed URLs now experience server errors, they will eventually be discarded if they continue to display 5xx status codes.
For more detailed information about these server errors and information about DNS and server errors, please refer to Google’s full help documentation.
Source: full Google help document.