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The SEO’s Guide to HTTP Status Codes

An HTTP status code is a three-digit number a server generates in response to a browser’s request. Like 404, for example, which you have likely seen before.

HTTP status codes, like 404, 301, and 500, might not mean much to a regular visitor, but they are incredibly important for SEO.

Not only that, search engine spiders, like Googlebot, use these to determine the health of a site. These status codes offer a way of seeing what happens between the browser and the server.

Several of these codes indicate an error, for instance, that the requested content can’t be found, while others simply suggest a successful delivery of the requested material.

In this article, we’re taking a closer look at the most important HTTP header codes and what they mean for SEO.

What is an HTTP status code?

In the client-server architecture of the World Wide Web (WWW), the interaction between browsers and websites is handled through the hypertext transfer protocol (HTTP).

This protocol was introduced in 1991 and is an official web standard. Almost all traffic on the web is handled through HTTP.

So, a status code is a piece of information returned by a web server in the HTTP response headers, after receiving a request for a file, such as a web page.

An HTTP status code is a three-digit number a server generates in response to a browser’s request.

If the server was able to process the request for the web page, the server will usually return a 200 HTTP status, along with the requested web page. This tells the web browser, or crawler, that the request was completed successfully.

What are the important HTTP status codes to know for SEO?

There are five different series of status codes. All status codes are three digits. The beginning digit highlights the type of status code returned by the server.

  • 1xx – Informational
  • 2xx – Success
  • 3xx – Redirection
  • 4xx – Client error (Broken links / missing pages)
  • 5xx – Server error

Read on for details about the key status codes SEOs should know.

200: OK / Success

This is how it probably should be; a client asks the server for content and the server replies with a 200 success message and the content the client needs.

The server and the client are happy — and the visitor, of course. All messages in 2xx mean some sort of success.

301: Moved Permanently

Arguably one of the most important status codes for SEO purposes, 301 redirects communicate that a web page has been permanently moved to a new location or a new URL.

When a user enters the URL in their browser, or clicks on a link with the old URL, they will be redirected to the new URL of the page.

If you don’t, users will see a 404 error page if they try to open the old URL and that’s not something you want. Using a 301 will make sure that the link value of the old URL transfers to the new URL.

302: Found

A 302 means that the target destination has been found, but it lives in a different location. However, it is a rather ambiguous status code because it doesn’t tell if this is a temporary situation.

So you will have to make sure that they make sense, since they mean temporary redirection and the destination page will not be taken into account by the search engines, as they understand that the site owner will go back to the older version once he’s done redefining the page.

This isn’t good for SEO, so make sure to look at them carefully.

Since you tell search engines that the URL will be used again, none of the link value is transferred to the new URL, so you shouldn’t use a 302 when moving your domain or making big changes to your site structure, for instance.

Also, when you leave 302 redirects in place for a long time, search engines can treat these 302 redirects as 301 redirects.

307: Temporary Redirect

The 307 code replaces the 302 in HTTP1.1 and could be seen as the only ‘true’ redirect. You can use a 307 redirect if you need to temporarily redirect a URL to a new one while keeping the original request method intact.

A 307 looks a lot like a 302, except that it tells specifically that the URL has a temporary new location. The request can change over time, so the client has to keep using the original URL when making new requests.

304: Not Modified

A 304 redirect is a type of HTTP response code that indicates that the requested resource has not been modified since the last time it was accessed by the client.

It means that the server does not need to send the resource again but instead tells the client to use a cached version.

The 304 response code is a way to save crawl budget for large websites. This is because Google’s crawler won’t recrawl unchanged pages and can instead focus on crawling new and updated pages.

403: Forbidden

A 403 tells the browser that the requested content is forbidden for the user. If they don’t have the correct login credentials, this content stays forbidden for that user.

These pages will not be indexed.

404: Not Found

As one of the most visible status codes, the 404 HTTP header code is also one of the most important. When a server returns a 404 error, you know the content has not been found and is probably deleted.

Try not to bother visitors with these messages, so fix these errors when you can. Use a redirect to send visitors from the old URL to a new article or page with related content.

A lot of 404 errors might be seen by Google as a sign of bad maintenance. Which in return might influence your overall rankings. If your page is broken and should be gone from your site, a 410 sends a clearer signal to Google.

410: Gone

The result from a 410 status code is the same as a 404 since the content has not been found. However, with a 410, you tell search engines that you deleted the requested content.

Thus, it’s much more specific than a 404. In a way, you order search engines to remove the URL from the index.

Before permanently deleting something from your site, ask yourself if there is an equivalent of the page somewhere. If so, make a redirect. If not, maybe you shouldn’t delete it and just improve it.

451: Unavailable for Legal Reasons

The 451 HTTP status code shows that the requested content was deleted for legal reasons.

If you received a takedown request or a judge ordered you to take specific content offline, you should use this code to tell search engines what happened to the page.

500: Internal Server Error

A 500 error is a generic message saying the server encountered an unexpected condition. This prevented it from fulfilling the request without determining what caused it.

These errors could come from anywhere. Maybe your web host is doing something funny, or a script on your site is malfunctioning. Check your server’s logs to see where things go wrong.

503: Service Unavailable

A 503 HTTP status code is a server-side error that indicates that the server is temporarily unable to handle the request. This could be due to overloading, maintenance, or other issues on the server.

A 503 status code can affect SEO if it lasts long, as it may signal to search engines that the site is unreliable or unavailable.

To avoid negative SEO impacts, a 503 status code should be used only for short-term situations and provide crawlers with a clear message about when the site will return online.


Make yourself familiar with these codes because you will see them pop up often. One look at the crawl errors in Google Search Console should be enough to show you how much is going on under the hood.

The above HTTP Status Code is by no means exhaustive i.e. we didn’t cover them all just the most frequently seen and used. For a list of the exhaustive list of all HTTP Status Code visit the link below:

These codes come in handy especially during API development and testing.

💬 Leave a response to this article by providing your insights, comments, or requests for future articles.

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Sunil Pradhan

Hi there 👋 I am a front-end developer passionate about cutting-edge, semantic, pixel-perfect design. Writing helps me to understand things better.

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Sunil Pradhan

Hi there 👋 I am a front-end developer passionate about cutting-edge, semantic, pixel-perfect design. Writing helps me to understand things better.