What are Response Codes?

What are Response Codes?

When a search engine or website visitor makes a request to a web server, a three digit HTTP Response Status Code is returned. This code indicates what is about to happen. A response code of 200 means "OK, here is the content you were asking for." A 301 says, "Gotcha. That page has moved, so I'll send you there now." And so on.

Einstein once said, "If you can't explain it simply, you don't know it well enough."


200 OK

A 200 is the most common type of response code, and the one we experience most of the time when browsing the web. We asked to see a web page, and it was presented to us without any trouble.

301 Moved Permanently

We were expecting to find a web page in a particular location, but it has been moved. No worries though, the web server has sent us to the new location. Most users won't notice that this has happened unless they watch the URL change.

302 Found (Moved Temporarily)

You're in the right place, but the page has moved temporarily to a new location. Just like a 301 the user doesn't usually notice anything because the web server seemlessly moves them to the new URL.

Important SEO Implication: A 302 isn't a permanent move. Any SEO strength that the original page had won't be granted to the new URL.

401 Unauthorized

We've requested a page, but a username and password are required to access it. We're presented with a way to login.

Important SEO Implication: Search engines won't submit a username and password for entry. If you have content hidden behind a login, it won't show up in the search results.

403 Forbidden

We've requested a page that we don't have permission to access at all. This page isn't for us.

404 Not Found

We've requested a page, but the web server doesn't recognize our request. The page can't be shown because the server doesn't know what it is.

Important SEO Implication: Most default 404 pages are a dead end for users and search engines. Look at using a custom 404 for these cases.

410 Gone

We've requested a page and the web server knows what we're asking for, but the page is gone.

Important SEO Implication: There is some debate in the SEO world as to the advantage (if any) of using a 410 over a 404 in certain cases.

Most SEOs prefer to use a 410 when removing unfavorable (perhaps penalized) content from a website. Perhaps the website has some bad links pointing to a bad neighborhood within an otherwise quality site. Its better to use a 410 to say, "We know what you're asking for, but we've deliberately removed it from the site, permanently."

500 Internal Server Error

We've requested a page, and in return, we get a generic error message. No information is given. It is like looking a sales associate in the eye, asking a question, and recieving a blank stare in return.

503 Service Unavailable

We asked for a page, but are told that it is temporarily unavailable. Something is wrong. Perhaps the website is down for maintenance.