9 Common Website Errors (+ How They Impact SEO)

Do you know the trick to avoiding most website errors?

It’s understanding what they actually are.

Don’t know the difference between your 401’s and 501’s? Want to learn what all those status codes in site audits mean?

This article will go over website error pages and the most common website errors that you’ll encounter.

What are website error pages?

Error pages are web pages shown to users when something went wrong with the page request.

Hypertext Transfer Protocol (HTTP) is the protocol for transferring web pages and communicates between browsers and servers. When you click a link, your browser makes a request to the web server hosting the content then waits until it receives a response alongside a response code.

When a response is successful, it sends the web page’s HTML body with a 2xx Successful response code.

The standard for HTTP response status codes was updated in RFC 7231, section 6: Response Status Codes by the Internet Engineering Task Force (IETF). The http status codes we’ll be going over are defined by this specification.

If you come across an error response not in this list, it is likely custom to that web server as it is a non-standard response.

What are the most common HTTP errors?

As every page request returns an HTTP response code, errors make up a fair amount of responses you’ll come across.

Response errors are grouped into two classes:

1. Client errors (4xx codes)
2. Server errors (5xx codes)

4xx Client errors typically appear when requests contain improper syntax or cannot be fulfilled. While 5xx Server-side errors usually arise when the server fails to fulfill a seemingly valid request.

What do these errors mean for SEO?

A 4xx client error simply means that the resource is unavailable and is not served. 4xx errors are bad business for SEO, as Google can’t access or index the page. You will not get any of the page’s content into search engines as it’s simply not accessible.

It completely stops both users and search engines from seeing it, making it pretty unhelpful for user experience.

A 5xx server error simply means something at the server level is preventing the request from being processed. This is a big problem for SEOs, as the page will not load for users or Google.

You should fix 4xx and 5xx errors as soon as possible.

However, the first digit of the status-code only defines the response class. The last two digits do not have any categorization role.

9 Common Website Errors (+ How To Fix Them)

Now let’s break down the specifics of these common website errors and how to fix them:

01. 401 Unauthorized

The 401 (Unauthorized) client error appears when the request lacks valid authentication credentials for the resource.

The 401 error typically occurs on websites requiring you to log in before you access them, but the authentication process failed, so your web browser denies you access.

If the request included authentication credentials, this response means authorization was refused for your credentials, but you can try again.

Luckily most 401 errors are simple to fix.

Quick 401 fix:

1. Make sure you used the correct URL
2. Clear browser cache
3. DNS flush

02. 400 Bad Request

The 400 (Bad Request) server error happens when the server can’t—or won’t—process the request due to something perceived to be a client error.

This can sometimes result from deformed request syntax, invalid request message framing, or deceptive request routing. A 400 status code can also result from a problem with the server.

Quick 400 fix:

1. Make sure you used the correct URL
2. Clear browser cache
3. DNS flush
4. Reduce file upload size

03. 403 Forbidden

The 403 (Forbidden) server error means the server understood the request but refuses to authorize it.

This is similar to the 401 (Unauthorized) error but differs as re-authenticating will make no difference—the request is forbidden.

However, a request might be forbidden for reasons unrelated to the credentials. This often occurs when requesting a resource with proper authentication through a login or resource key.

Quick 403 fix:

1. Generate a clean .htaccess file
2. Temporarily deactivate your CDN

Because the 403 Forbidden error means your server is working, but you don’t have permission to view your site, we recommend you reach out to your hosting provider so they can help you pinpoint the issue and get you back up and running.

04. 404 Not Found

The 404 (Not Found) server error means the server could not find the requested resource. Broken inks leading to 404 pages are considered broken or dead and contribute to link rot.

If the resource once existed but was permanently removed, it’s better to use the 410 (Gone) server error, as it means the resource is likely to be no longer available in the future.

By default, a 404 response is cacheable to minimize performance issues, as this is the most common error you’ll see.

Quick 404 fix:

1. Refresh the page
2. Make sure you used the correct URL
3. Clear browser cache
4. DNS flush
5. Create redirects for moved content

05. 408 Request Timeout

The 408 (Request Timeout) server error means that the server didn’t receive a complete request message within the time that it was set to wait.

The 408 error happens when a server decides to close connections that take too long. Servers sometimes close the connection without sending this error response.

Quick 408 fix:

1. Refresh the page
2. Make sure you used the correct URL
3. Check your internet connection
4. Increase server resources

06. 500 Internal Server Error

The 500 (Internal Server Error) server error indicates that the server encountered an unexpected condition that prevented it from fulfilling the request.

Basically, the server encountered a situation; it doesn’t know how to handle it, and it doesn’t have a better 5xx error code. The 500 response code is a generic error response.

Sometimes, admins will log these error responses like the 500 status code with more information about the request to help debug and prevent it from happening again.

Quick 500 fix:

1. Refresh the page
2. Make sure you used the correct URL
3. Check your internet connection
4. Check permissions on PHP and CGI files
5. Generate a clean .htaccess file

07. 501 Not Implemented

The 501 (Not Implemented) server error means the server doesn’t recognize or support the request method.

Request methods indicate the desired action to be performed for a given resource: GET, HEAD, POST, PUT, DELETE, CONNECT, OPTIONS, TRACE, PATCH. These are defined by RFC 7231, section 4: Request methods.

The only methods servers need to support are GET and HEAD, as GET is the default request and HEAD returns the headers of a GET request.

By default, A 501 response is cacheable. When cached, it’s stored to be retrieved later instead of making another request to the server.

Quick 501 fix:

1. Refresh the page
2. Make sure you used the correct URL
3. Clear browser cache
4. DNS flush
5. Contact your host

08. 502 Service Temporarily Overloaded

The 502 (Bad Gateway) server error means that while attempting to fulfill the request, the server acted as a gateway and received an invalid response from an inbound server.

The gateway can refer to different things regarding networking, and this error is not usually something you can fix as it requires a fix to the web server or the proxies you are accessing.

Quick 502 fix:

1. Refresh the page
2. Make sure you used the correct URL
3. Clear browser cache
4. DNS flush
5. Contact your host

09. 503 Service Unavailable

The 503 (Service Unavailable) server error means the server is not ready to handle the request.

Often this is due to scheduled maintenance or a temporary overload and is resolved after some time. The server can send a Retry-After header suggesting how long to wait before retrying the request.

A 503 response can also appear when a server is merely refusing the connection.

Quick 503 fix:

1. Refresh the page
2. Make sure you used the correct URL
3. Temporarily deactivate your CDN
4. Contact your host

10. Bonus: Not Secure

Here’s a bonus one for you. If your site loads over HTTP, Google will flag your site to users in bright red text as “Not secure.”

With Google’s SSL requirements, bad SSL implementations can ruin your SEO.

This is so crucial that we even launched an SSL migration service to ensure that no problems arise for our clients.

(SEO) Errors and mistakes happen.

You have to always be on the lookout to avoid SEO mistakes. Avoiding mistakes can be a competitive edge that significantly impacts the success of your business.

Error response codes are never a good sign, but fixing them doesn’t have to be painful. Armed with the knowledge of the most common response errors, you can be confident the next time you come across one during an audit or merely browsing the web.

And if you’re looking to find and fix technical problems, technical SEO tools are a godsend to your toolbox.