HTTP status codes: A quick guide for better SEO

Key takeaways

• HTTP status codes indicate a server’s response to a request, helping browsers and search engines determine a page’s status.
• Certain status codes affect SEO by influencing how search engines index pages. For instance, a 404 error blocks indexing, while a 200 OK allows it.
• Fixing errors like 404 improves crawlability and strengthens SEO rankings.

We’ve all encountered an error message in our browser that leaves us scratching our heads. An error 404 Not Found? A 500 Internal Server Error? It might feel like we’re at a dead end with no solution in sight.

But other than being petty nuisances, these HTTP status codes are indicators of what’s wrong behind the scenes of your website. They are a vital part of how web servers communicate with browsers and search engines, letting us know the state of a requested page.

In this guide, we’ll explain HTTP status codes and their significance, particularly how they affect your website’s SEO. We’ll also explore the meaning behind each status code class—from Error 1xx to 5xx—and help you troubleshoot common HTTP error messages.

What are HTTP status codes

HTTP status codes tell us how a server has responded to a request. The request comes from your browser when you look up a URL or click a link. The server processes the request and communicates using a status code, letting you and the browser know the result of the request.

These codes fall into different categories, known as status code classes. You can determine the type of the response through the first digit of the code:

• 1xx (Informational): 1xx codes tell us that the server has received the request and is in the process of handling it. Users can rarely see them. Below are typical examples of this class.

Code	Text	Description
100	Continue	The server got the request and is giving the signal to continue with the process.
101	Switching Protocols	The server is changing the communication protocol as the client requested.

• 2xx (Successful): The 2xx status codes let you know that the server successfully processed the request. Below are common codes for this class.

Code	Text	Description
200	OK	The request was successful, and everything worked as expected.
201	Created	The request (get, post, or delete) was successful, and a new resource has been added to the server.
202	Accepted	The request has been received, but the processing is not yet complete.
203	Non-Authoritative Information	The request succeeded, but the information provided might be from an outside source.
204	No Content	The request was successful, but no additional content is being returned.
205	Reset Content	The request was successful, but the server requires the user to reset the page view.
206	Partial Content	The server has provided part of the content that was requested, often used for resuming downloads.

• 3xx (Redirection): These codes tell the browser and/or the user to take additional action to fulfill the request. Most actions involve redirecting to a different page. The following are common examples of 3xx error codes.

Code	Text	Description
300	Multiple Choices	The request can be completed in several ways, with different possible responses.
301	Moved Permanently	The resource has been permanently moved to a new Uniform Resource Identifier (URI), and the old one is no longer valid.
302	Found	The resource has been temporarily moved, and the client should follow the new URI for the time being.
303	See Other	The resource can be found at a different URI, and the client should go there for the response.
304	Not Modified	The resource hasn’t changed since the last time it was requested, so no new content is returned.
305	Used Proxy	The resource can only be accessed via a specific proxy, which must be used for the request.
307	Temporary Redirect	The resource has been temporarily moved, and the client should access the new URI.
308	Permanent Redirect	The resource has permanently moved to a new URI, and future requests should go to that location.

• 4xx (Client Error): The 4xx codes tell us that something is wrong with the request from the client’s side. The infamous 404 (Not Found) is one of the most common, indicating that the requested page doesn’t exist. Besides the said error, below are some of the well-known 4xx errors.

Code	Text	Description
400	Bad Request	The Expect request header field is either invalid or incorrectly formatted, so the server can’t process the request.
401	Unauthorized	The server requires user authentication before the request can be processed.
403	Forbidden	The server understands the request but refuses to authorize it, usually due to insufficient permissions.
404	Not Found	The server can’t find the requested resource, or it no longer exists.
405	Method Not Allowed	The request method isn’t allowed for the resource you’re trying to access.
406	Not Acceptable	The server can’t produce a response that fits the client’s criteria, often related to content types.
407	Proxy Authentication Required	The client must authenticate itself with a proxy before the request can proceed.
408	Request Timeout	The server timed out while waiting for the request to be sent, meaning it took too long to process.
409	Conflict	The request can’t be processed because it conflicts with the current state of the resource.
410	Gone	The resource you requested is no longer available and will not be coming back.
411	Length Required	The server requires a valid Content-Length header to process the request but didn’t find one.
412	Precondition Failed	A condition set by the request header field didn’t meet the necessary requirements, so the server can’t proceed.
413	Request Entity Too Large	The server can’t process the request because it’s too large for it to handle.
414	URI Too Long	The provided URI is too long for the server to process, so the request was rejected.
415	Unsupported Media Type	The media type in the request entity is not something the server or resource can process.
416	Range Not Satisfiable	The server cannot satisfy the range specified by the client in the request, such as partial content.
417	Expectation Failed	The server can’t meet the expectations defined in the Expect request header field, so it’s unable to proceed.
429	Too Many Requests	The user has sent too many requests in a given period.

• 5xx (Server Error): The 5xx codes indicate that the server has encountered an error and cannot process the client’s request. One common example is 500 Internal Server Error, which points to a problem on the server side.

Code	Text	Description
500	Internal Server Error	Something unexpected happened on the server, and it can’t process the client’s request.
501	Not Implemented	The server can’t handle the request because it doesn’t have the necessary functionality to do so.
502	Bad Gateway	The server, acting as a gateway, received an invalid response when trying to communicate with another server.
503	Service Unavailable	The server is temporarily overwhelmed or undergoing maintenance and can’t process the request.
504	Gateway Timeout	The server, while acting as a gateway, didn’t receive a response in time from another server it was trying to reach.
505	HTTP Version Not Supported	The server can’t process the request because it doesn’t recognize or support the HTTP version used. in the request.
521	Web Server Is Down	The server is down or not responding to requests.
522	Connection Timed Out	The server took too long to respond to a request, causing a timeout.

How do HTTP error codes affect SEO

HTTP status codes are also important for your website’s SEO. In addition to giving you insight into the communication between a client and a server, status codes also help search engine crawlers, such as Googlebot, assess the health of your website.

The HTTP error messages also affect how search engines index your pages (add to search results). For instance, if one of your pages is blocked due to a 403 Forbidden Error, crawlers won’t be able to access the page’s content. Because search engines can’t index it, this limits your site’s visibility on search engines.

To know more about the status codes’ effect on your website’s SEO, here are the most common codes that have a significant impact on SEO:

200 OK

This is the “all clear” signal from the server. It means that everything worked perfectly, and the requested page is available. From an SEO perspective, a 200 OK code is the ideal status to have because it tells search engines that the page is active and can be indexed.

301 Moved Permanently

This status code indicates that a page has been permanently moved to a new address or URL. It’s like when you’re moving to a new house, and you inform your friends to update their address book.

In SEO, 301 redirects are important because they ensure that the value of the old page gets passed onto the new page by providing the requester a forwarding address. This helps keep the page ranking in search results. However, be mindful when using 301 redirects, as redirect chains can lead to delayed crawling and slow down your website. It can also lead to link juice loss or that boost that you get from trustworthy backlinks. For instance, with one redirect from a reputable site, but when adding another redirect, you may get just over 72% of the total link juice. As a result, it can affect your overall SEO performance.

However, be mindful when using 301 redirects, as redirect chains can lead to delayed crawling they can and slow down your website. It can also lead to link juice loss or that boost that you get from trustworthy backlinks.

307 Temporary Redirect

A 307 Temporary Redirect is like 301, but it’s used only for temporary redirection. In SEO, this is less helpful than a 301 redirect because it doesn’t pass along the link value. It’s only useful if you need to temporarily redirect traffic without affecting rankings.

403 Forbidden

This response code means the server refuses to let you access the page. This situation isn’t good for SEO because a user agent can’t get to the page, so they can’t index it. If many pages on your site have this error, Google may think your site is broken or untrustworthy.

404 Not Found

This error means that the page you were trying to visit doesn’t exist. Having many of these errors can hurt your site’s SEO rankings because they give a terrible user experience and suggest that your site is unorganized. It’s best to fix these by removing broken links or redirecting to active pages.

500 Internal Server Error

This is a general error that means something went wrong on the server side. There may be problems with your site’s host, or some of its scripts may be broken. In any case, you need to have it fixed as soon as possible because if search engines run into this too often, they’ll have trouble indexing your site, which can hurt your SEO.

503 Service Unavailable

In 503 errors, the server is temporarily unable to process any requests. The problem might be due to maintenance or overloading. This error is less damaging than a 500 error because it suggests the issue is temporary. However, if the issue lasts long, search engines might think your site is unavailable or unreliable, negatively affecting your SEO performance.

How to troubleshoot HTTP status codes

HTTP status codes inform you what is wrong with a web page when it encounters error messages. Depending on the error, there are ways to fix them from your side. First, you need to check the error message. You can use your browser’s developer tools to check the status code if it’s not displayed on the page.

Here’s how you can do it:

1. Open the Developer Tools  

• In Chrome or Firefox, right-click anywhere on the page and select Inspect or press Ctrl + Shift + I, if you’re using Windows, or Cmd + Option + I if you’re using Mac.
• In Safari, enable Developer Tools in Preferences > Advanced, then right-click and select Inspect Element.

2. Go to the ‘Network’ Tab

• This will allow you to see all requests the page makes under the Status column.

3. Reload the page.

• With the Network tab open, refresh the page. This will capture all the HTTP requests.

4. Find the request for the page

• Look for the page’s main URL in the list of requests. It’s usually at the top of the result.
• Click on it, and you will see more status code details in the right-hand panel.

This tool identifies if your page is returning a status code that might affect your SEO’s effectiveness. Below are ways on how you can fix the most common HTTP errors:

403 Forbidden

• Check permissions: Since this error happens when the server says “No” to your request, double-check your website’s settings to make sure nothing’s blocking search engines from accessing the page.
• Review .htaccess File: If your server allows, check your .htaccess file for any rules that could be blocking access. You can find this file in your web host’s cPanel.
• Check for restrictions: If you use a security plugin or firewall, check for any security rules blocking the request.

404 Not Found

• Fix broken links: This response code is common when pages are deleted or moved. Google Search Console is useful in finding broken links, so you can update these links or use a 301 redirect to fix the error.
• Set up redirects: If a page is deleted, make sure to set up a 301 redirect to send users to a relevant page. If there is none, then you can redirect the deleted page to the homepage.

500 Internal Server Error

• Check server logs: Internal configuration error on the server’s end usually causes this error. Check the server logs for detailed error messages. Your hosting service provider should be able to assist you with how to access these if you’re not sure where to find them.
• Clear caches: Sometimes 500 errors are caused by old, cached data. Clear your site’s cache, disable caching temporarily, or open the page using your browser’s Incognito mode to see if the problem persists.
• Fix plugins or themes: If you’re using WordPress and recently installed a new plugin or theme, see if disabling it fixes the issue. There may be a conflict between the plugin or theme and the server.

503 Service Unavailable

• Check server status: A 503 error can happen when the server is too busy or temporarily down. Check with your hosting provider to see if they’re doing maintenance or if there’s an overload of traffic.
• Wait it out: If the error is temporary, just wait and try again later. It should resolve on its own once the server is back to normal.
• Check for server overload: If your site is getting too much traffic, it may cause the server to crash. Upgrading to a bigger hosting plan or using a content delivery network (CDN) to help handle the traffic better might help fix this error.

Tools for checking HTTP status codes

Besides your browser’s developer console, you can use other tools to check HTTP status codes. Below are some of the best tools to help you monitor and manage HTTP responses efficiently.

HTTPStatus.io

HTTPStatus.io is a free online tool that allows you to check the HTTP status codes of multiple URLs at once. To use it, go to HTTPStatus.io and enter the URLs you want to check in the input box. Click the “Check Status” button. The tool will display the HTTP status code for each URL along with details like redirect paths and response headers. 

Google Search Console

Google Search Console is a free tool that helps you monitor and optimize your site’s SEO performance. It provides insights into indexing issues, including pages returning HTTP errors like 404 (Not Found) or 500 (Internal Server Error).

To check HTTPS status codes in Google Search Console, log in with your Google account and select your website property. Navigate to Pages under the Indexing section. Here, you’ll see pages categorized under different statuses. Click on a specific error to see affected pages and Google’s explanation. If you fix the issue, return to the report and click Validate Fix to ask Google to recrawl the page.

Screaming Frog SEO Spider

Screaming Frog SEO Spider is a desktop-based website crawler that analyzes your site’s structure, finding broken links, redirects, and HTTP status codes. It’s widely used by SEO professionals to efficiently audit large websites.

To check your site’s HTTP status using this tool, download and install the program first. Then open it and enter your website URL in the search bar. Click Start to begin crawling your website. Once the crawl is complete, navigate to the Response Codes tab. You can filter the results to see specific HTTP status codes. Click on any URL to see more details about the response. If you need to, you can export the report to analyze it further using the Export function.

Ahrefs Site Audit

Ahrefs Site Audit is an SEO tool that crawls your website and detects errors, including HTTP status codes affecting your site’s performance. It provides a detailed health score and recommendations for fixes.

You can check error codes using Ahrefs Site Audit by signing into your account first through Ahrefs. Then navigate to Site Audit in the main dashboard. Add your website URL and start a new crawl. Once the audit is complete, go to the Internal Pages report and filter by HTTP Status Codes to view the error codes. Click on any error to see the affected pages and suggestions for fixing them.

Enhance your site’s performance and SEO with Domain.com

HTTP status codes reveal what’s happening between your browser and the server when loading a web page. Understanding these codes and how to address them can boost your site’s performance and positively impact your search engine rankings.

Another key factor in improving your site’s SEO is choosing a reliable hosting provider like Domain.com. With the right SEO tools, mobile-friendly web designs, SSL certificates, and built-in optimization features, you can enhance your site’s visibility and improve user experience.

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