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What are HTTP Status Codes

December 10, 2023

HTTP status codes, also known as browser error codes or internet error codes, indicate whether a particular HTTP request is successful or not.

Whenever you try to access a specific website and enter its URL in your browser, the browser sends your request to the web server of that website. Upon receiving the request, the web server processes it and returns the response with an HTTP header.

This HTTP header consists of the HTTP status codes. Every time your browser makes a request for a web page or resource to the web server, you receive the HTTP status codes; however, you do not notice them most times. You usually notice them when something goes wrong and doesn’t find what you requested.

Let us explore more about HTTP status codes in this article.

What are HTTP Status Codes?

HTTP status codes are the response codes the web server sends as a response to a web browser when it requests the desired resource. When the requested resource (web page) does not load properly in a browser, these codes help you identify the major cause.

An alternate term for the HTTP status code is the HTTP status line. Primarily, the HTTP status line consists of a code and the corresponding reason phrase.

For instance, the HTTP status line: 404: Bad Request consists of the HTTP status code: 400 and the HTTP reason phrase: Bad Request.

Types of HTTP Status Codes

HTTP response codes are categorized into the following five groups:

100: Informational Responses
200: Successful Responses
300: Redirection Responses
400: Client-Error Responses
500: Server-Error Responses

I shall explain all these groups in detail below.

100: Informational Responses

This group of status codes indicates that the request from the client to the server is still in progress. 100-level status codes do not necessarily have to be errors; they provide additional information to help you know what exactly is going on.

100-level HTTP Status Codes	Description
100 Continue	It indicates that the web server has received only a part of the request. The client can continue to send the request, as the web server has not rejected it.
101 Switching Protocols	The web server changes the protocol as requested by the browser.
102 Processing	The code indicates that the server is processing the request from the client, but the response is not yet ready.
103: Early Hints	It returns some response headers before the server sends a complete response.

200: Successful Responses

The 200-level HTTP response codes indicate that everything is functioning as intended, i.e., the client receives the expected response.

200-level HTTP Status Codes	Description
200 OK	It indicates that a certain HTTP request is successful.
201 Created	The web server has fulfilled the browser’s request and hence, has created a new resource.
202 Accepted	It specifies that the web server has accepted the browser’s request for processing. The server is still processing the request and has not completed it.
203 Non-Authoritative Information	When there is a use of a proxy server, it receives the response code 200: OK from the origin server. However, it sends the modified version of the original response to the browser.
204 No Content	The code indicates that the web server has processed the request successfully but is not going to return any content.
205 Reset Content	The web server asks the browser to reset the document view while it has processed the request successfully but is not returning any content.
206 Partial Content	This status code leverages range headers that allow you to resume your paused downloads or split a download into multiple streams. The server sends only the part of the response because the client has sent range headers.

300: Redirection Responses

Basically, redirection is the process of conveying that the resource has been located from its original place to a new one. Redirection responses provide clients with information about the location where they can find the requested content.

300-level HTTP Status Codes	Description
300 Multiple Choices	Many times the web server provides multiple resources to a browser’s requests. As a result, the browser can choose from multiple options available.
301 Moved Permanently	It indicates that the current and all further requests should be redirected to the given URI, as the resource has been located permanently.
302 Found	The browser finds the requested resource but not at the intended location. It indicates the temporary URL redirection.
303 See Other	This code indicates that it has found the resource your browser requested via POST, DELETE, or PUT methods. You can retrieve the resource by making a request using the GET method to a different URI (different from the one used before).
304 Not Modified	It specifies that the resource stored in your browser’s cache is not modified since you accessed it for the last time.
305 Use Proxy	The browser can access the resource only through a proxy whose address is received in a response from the server.
306 Switch Proxy	All the subsequent requests should use a different proxy.
307 Temporary Redirect	The web server sends this response code to the client, stating that they can find the requested resource at a different URL but using the same method as used in the previous request.
308 Permanent Redirect	This indicates that the resource has been permanently moved to a different URI.

400: Client-Error Responses

The 400-level status codes are codes that specify something is wrong on the error client side, i.e., there is an issue with the browser or the request.

400-level HTTP Status Codes	Description
400 Bad Request	The server will not return the response due to a client error, such as the invalid syntax of the request, size too large,
401 Unauthorized	The client has to authenticate themselves to receive the request-response.
402 Payment Reminder	Initially, the code was created to use in digital payment systems. But this never happened, and hence the is not used widely.
403 Forbidden	The web server refuses to provide the requested resource because the client does not have access rights.
404 Not Found	It indicates that the server does not find the requested resource.
405 Method Not Allowed	This code specifies that the requested resource does not support the request method.
406 Not Acceptable	It states that the requested resource only generates content that is not acceptable by the accept header in the request.
407 Proxy Authentication Required	The client should authenticate themselves with the proxy first.
408 Request Timeout	It specifies that the client did not make any request within the time the server was prepared to wait.
409 Conflict	Due to the conflict in the current state of the resource, the server could not process the client’s request.
410 Gone	Similar to 404: Not Found. Also, 410: Gone specifies that the condition is permanent and expected.
411 Length Required	The client has not specified the length of the content required by the requested resource.
412 Precondition Failed	The server did not satisfy any of the pre-conditions the client imposed on the request headers.
413 Payload Too Large	The request is larger than the server is capable of processing it.
414 URI Too Long	The length of the URI is larger for the server to process.
415 Unsupported Media Type	The request has a media type that the server or resource does not support.
416 Range Not Satisfiable	It specifies that the request was the portion of a resource that the server was not able to return.
417 Expectation Failed	The server is not capable of fulfilling the needs of the Expect request-header field.
418 I’m a Teapot	Teapots return this code when they receive the request for brewed coffee.

Also Read:

500: Server-Error Responses

Like 400-level status codes, 500-level codes are also errors but on the server side. These codes define the issues on the server side and are pretty tricky to resolve.

500-level HTTP Status Codes	Description
500 Internal Server Error	This indicates that something is wrong with the server, and the requested resource is not delivered to the client.
501 Not Implemented	The server either does not identify the request method or has no ability to fulfill the request.
502 Bad Gateway	When the server acts as a gateway or proxy, it receives an invalid response from the upstream server.
503 Service Unavailable	The server is not able to handle the request as it is down for maintenance or overloaded.
504 Gateway Timeout	The server was acting as a gateway or proxy and has not received the response in time from the upstream server.
505 HTTP Version Not Supported	The server is not compatible with the HTTP version used in the request.
506 Variant Also Negotiates	A circular reference is produced via transparent content negotiation for the request.
507 Insufficient Storage	There is no sufficient storage on the server to store the representation required to fulfill the request.
508 Loop Detected	The server detected the infinite loop while processing the request.
510 Not Extended	In order to fulfill the request, the server requires further extensions to the request.
511 Network Authentication Required	It specifies the need for client authentication so that the client can access the network.

Also Read: 4 Ways to Fix “DNS Probe Finished No Internet” Error in Chrome Browser

To Sum It Up: HTTP Status Codes

This was all about the HTTP status codes and different types. These status codes are actually informative though they seem intimidating. When you learn some of the major HTTP response codes, you can easily troubleshoot problems on your website. I hope you will find this article helpful in identifying which status code you receive when you request information on the internet.