2020 / FEBRUARY / 27

5XX Response Codes

Introduction

HTTP Status codes are basically the conversion between the web browser and the website's server. In most cases, you as a user won't be able to see the HTTP status codes unless and until there is an issue. In case of issue HTTP status codes are used as a way of communicating errors to the user.

Response messages or we can say HTTP codes are displayed when your internet browser is unable to reach the page requested by a user.

What is a 5xx Response?

HTTP status codes or Response codes that fall into the 5xx category, specify problems with the server.

When you visit a website, your web browser will send your request to the web server. If there is an issue at the server site, it will return a 5xx response code.

Generally, this response suggests that the problem is not with your computer, internet connection or website and more often it is an issue at the server-side.

What do 5xx Responses Look Like?

A 5xx response is generally a problem on the server not on the client-side. They are visible in any operating system, software installation, so you may encounter this error message when using a desktop computer or a smartphone or a tablet. Server errors are mostly displayed inside a web browser window. For instance, you may encounter a 500 Internal Server error like this-

Or a 502 Bad Gateway error like this-

503 Error looks like this-

And 504 error may look like this-

Every HTTP 5xx response code have there own set of variations. Different browsers or servers or applications are free to customise the response. We will talk about specific response codes in different articles.

A Guide to HTTP 5xx Response

There are a number of different 5xx server responses, numbered with their own response codes so that the problem can be identified.

Some of the most common HTTP 5xx Response codes are listed below:

S no.	Response Code	Response Name	Description
1	500	Internal Server Error	A generic error message for situations when an unexpected condition was encountered.
2	501	Not implemented	The server either lacks the ability to fulfill the request or does not recognize the request method.
3	502	Bad Gateway	The server was acting as a gateway, received an invalid response from the upstream server.
4	503	Service Unavailable	This is a temporary state. The server is unable to handle the request (because it is overloaded or down for maintenance).
5	504	Gateway Timeout	The server was acting as a gateway and did not receive a timely response from the upstream server.
6	505	HTTP Version Not Supported	The server cannot handle the HTTP version used in the request.
7	506	Variant Also Negotiates	Transparent content negotiation for the request results in a circular reference.
8	507	Insufficient Storage	The server is unable to complete the request due to insufficient space to store the representation.
9	508	Loop Detected	The server detected an infinite loop while servicing the request.
10	510	Not Extended	The server is unable to process the request due to the absence of further extensions to the request.
11	511	Network Authentication Required	Intended for use by intercepting proxies used to control access to the network. The client needs to authenticate to gain network access.

Unofficial Codes

S no.	Response Code	Response Name	Description
1	509	Bandwidth Limit Exceeded	The server has exceeded the bandwidth specified by the server administrator; this is often used by shared hosting providers to limit the bandwidth of customers.
2	526	Invalid SSL Certificate	Used by Cloudflare and Cloud Foundry's Gorouter to indicate failure to validate the SSL/TLS certificate that the origin server presented.
3	529	Site is Overloaded	Used by Qualys in the SSLLabs server testing API to signal that the site can't process the request.
4	530	Site is Frozen	Used by the Pantheon web platform to indicate a site that has been frozen due to inactivity.
5	598	Network read timeout error	Used by some HTTP proxies to signal a network read timeout behind the proxy to a client in front of the proxy.

Cloudfare's expansion of codes

S no.	Response Code	Response Name	Description
1	520	Web Server Returned an Unknown Error	The origin server returned an empty, unknown, or unexplained response to Cloudflare.
2	521	Web Server Is Down	The origin server has refused the connection from Cloudflare.
3	522	Connection Timed Out	Cloudflare could not negotiate a TCP handshake with the origin server.
4	523	Origin Is Unreachable	Cloudflare could not reach the origin server; for example, if the DNS records for the origin server are incorrect.
5	524	A Timeout Occurred	Cloudflare was able to complete a TCP connection to the origin server but did not receive a timely HTTP response.
6	525	SSL Handshake Failed	Cloudflare could not negotiate a SSL/TLS handshake with the origin server.
7	526	Invalid SSL Certificate	Cloudflare could not validate the SSL certificate on the origin web server.
8	527	Railgun Error	It indicates an interrupted connection between Cloudflare and the origin server's Railgun server.

5xx Response Impact on SEO

When Google gets a 5xx response on a website, it lowers that page ranking or drops it from the index. Of course, your page ranking will not drop as soon as 5xx response appears. There have to be multiple causes of occurrence of 5xx response over a week or two for a page to get removed from the Google index. So, you will have plenty of time to correct the error.

A search engine can't crawl and analyze your site if it gets 500 and 503 responses. This also means that 5xx response codes can cause poor user experience and negatively impact your site's ranking and indexing.

If your site is only down for say 10 minutes and it's being crawled consistently a lot of times the crawler will simply get the page delivered from the cache. However, if the site is down for an extended period of time, say 6+ hours, then Google might see the 5xx response as a site-level issue that needs to be addressed. This could impact your rankings.

3 simple steps to clear HTTP 5xx Response

HTTP 5xx response code is a server-side problem, meaning the issue is most likely at the server end. The problem is not likely to lie within your internet connection or device.

Here are a few simple steps that you can take before seeking further help or advice:

Refresh your browser: The problem can only be temporary and can be solved by simply refreshing the browser and reloading the web page.
Remove Browser Cookies: Sometimes 5xx response codes due to the cookies that are used for tracking and saved while we browse a website. Simply deleting these cookies and refreshing the browser can often solve the problem.
Contact your host/ server: If the problem still persists, it is better to contact your host or server so that they can provide an error code specific remedy. Chances are they are already undergoing maintenance to resolve the error.