Exploring the Foundations of Web Communication: Understanding HTTP Status Codes

By LightNode ·


The internet is a vast realm where every click of a link or form submission sets off an intricate exchange between your device and servers hosting the requested content. At the heart of this interaction lies the Hypertext Transfer Protocol (HTTP) – the fundamental protocol governing communication across the World Wide Web. Crucial to this flow of information are HTTP status codes – succinct numerical codes relayed by servers to communicate the outcome of a client's request.

When you open a webpage, you're essentially sending a request to a server out there on the internet. The server receives this request and formulates a response – this back-and-forth is the essence of how HTTP operates. Status codes are like the server's reply, using numerical codes to indicate how your request was handled.

Status codes are vital not just for us end-users, but also for website owners and developers to understand how their systems are performing. Grasping the meaning behind these codes allows for efficient troubleshooting and issue resolution. In essence, while HTTP status codes may seem like mere numbers, they offer a glimpse into the fundamental workings of internet communication. Understanding them is akin to learning an ingenious language that elucidates the rules and wisdom underpinning the World Wide Web's operations. So let's continue exploring all of HTTP Status Codes.

All HTTP Status Codes

List of HTTP Status Codes

1xx Informational

  • 100 Continue: The server has received the request headers and the client should proceed to send the request body
  • 101 Switching Protocols: The requester has asked the server to switch protocols
  • 102 Processing: Indicates that the server has received and is processing the request, but no response is available yet
  • 103 Early Hints: Used to return some response headers before final HTTP message

2xx Success

  • 200 OK: Standard response for successful HTTP requests
  • 201 Created: The request has been fulfilled, resulting in the creation of a new resource
  • 202 Accepted: The request has been accepted for processing, but the processing has not been completed
  • 203 Non-Authoritative Information: The server successfully processed the request, but is returning information that may be from another source
  • 204 No Content: The server successfully processed the request and is not returning any content
  • 205 Reset Content: The server successfully processed the request, but is not returning any content. The client should reset the document view
  • 206 Partial Content: The server is delivering only part of the resource due to a range header sent by the client
  • 207 Multi-Status: Provides status for multiple independent operations
  • 208 Already Reported: The members of a DAV binding have already been enumerated in a preceding part of the multistatus response
  • 226 IM Used: Indicates that the server has fulfilled a request for the resource, and the response is a representation of the result of one or more instance-manipulations

3xx Redirection

  • 300 Multiple Choices: Indicates multiple options for the resource
  • 301 Moved Permanently: This and all future requests should be directed to the given URI
  • 302 Found: Tells the client to look at (browse to) another URL
  • 303 See Other: The response to the request can be found under another URI using the GET method
  • 304 Not Modified: Indicates that the resource has not been modified since the version specified by the request headers
  • 305 Use Proxy: The requested resource is available only through a proxy
  • 307 Temporary Redirect: The request should be repeated with another URI
  • 308 Permanent Redirect: The request and all future requests should be repeated using another URI

4xx Client Error

  • 400 Bad Request: The server cannot or will not process the request due to an apparent client error
  • 401 Unauthorized: Authentication is required and has failed or has not been provided
  • 403 Forbidden: The request was valid, but the server is refusing action
  • 404 Not Found: The requested resource could not be found
  • 405 Method Not Allowed: A requested method is not allowed for the requested resource
  • 406 Not Acceptable: The requested resource can only generate content not acceptable per the Accept headers
  • 407 Proxy Authentication Required: The client must first authenticate itself with the proxy
  • 408 Request Timeout: The server timed out waiting for the request
  • 409 Conflict: Indicates that the request could not be processed because of conflict
  • 410 Gone: Indicates that the resource requested is no longer available
  • 411 Length Required: The request did not specify the length of its content
  • 412 Precondition Failed: The server does not meet one of the preconditions
  • 413 Payload Too Large: The request is larger than the server can process
  • 414 URI Too Long: The URI provided was too long for the server to process
  • 415 Unsupported Media Type: The request entity has an unsupported media type
  • 416 Range Not Satisfiable: The client requested an invalid range of the file
  • 417 Expectation Failed: The server cannot meet the requirements of the Expect header
  • 418 I'm a teapot: The server refuses to brew coffee in a teapot
  • 421 Misdirected Request: The request was directed at the wrong server
  • 422 Unprocessable Entity: The request was valid but cannot be processed
  • 423 Locked: The resource is currently locked
  • 424 Failed Dependency: The request failed due to failure of a previous request
  • 425 Too Early: The server refuses a request that might be replayed
  • 426 Upgrade Required: The client should use a different protocol
  • 428 Precondition Required: The request requires conditional headers
  • 429 Too Many Requests: The user has sent too many requests
  • 431 Request Header Fields Too Large: The server won't process large headers
  • 451 Unavailable For Legal Reasons: Resource access denied for legal reasons

5xx Server Error

  • 500 Internal Server Error: A generic error indicating an unexpected condition
  • 501 Not Implemented: The server doesn't recognize the request method
  • 502 Bad Gateway: The server received an invalid response from an upstream server
  • 503 Service Unavailable: The server is currently unavailable
  • 504 Gateway Timeout: The server did not receive a timely response from upstream
  • 505 HTTP Version Not Supported: The server does not support the HTTP version
  • 506 Variant Also Negotiates: Transparent negotiation caused a circular reference
  • 507 Insufficient Storage: The server has insufficient storage to complete the request
  • 508 Loop Detected: The server detected an infinite loop while processing
  • 510 Not Extended: Further extensions are required for the server to fulfill the request
  • 511 Network Authentication Required: The client needs to authenticate to gain network access

FAQ about HTTP Status Codes

What is the different between CLient and Server?

  • Client: A client is typically a web browser or application running on a user's device (computer, phone, etc.) that initiates requests to servers for resources like web pages, files, or data. The client sends HTTP requests and receives HTTP responses from servers.

  • Server: A server is a computer program or system that receives incoming HTTP requests from clients, processes them, and sends back appropriate HTTP responses. Servers host and manage the resources (web pages, files, databases, etc.) that clients request access to over the network.

Can a LightNode server be a client?

Certainly, a LightNode server, being a VPS, can act both as a server and a client.. Here's how it works:

  • As a Server: A LightNode VPS server can host websites, databases, applications, and more. In this role, it serves content or services to client devices or other servers across the internet or local networks. It listens for incoming requests and provides the appropriate responses or data.

  • As a Client: The same LightNode server can also act as a client when it needs to request information or services from the internet or other servers. This could include fetching data from APIs, downloading software updates, or accessing online resources. In these instances, the VPS initiates the requests and waits for responses, just like any other client device would.

Can HTTP status codes be customized?

Yes, HTTP status codes can be customized to some extent by web developers and server administrators. Customizing status codes allows for more meaningful communication with clients and can enhance the user experience by providing tailored error messages or redirection instructions.

How do HTTP status codes affect SEO and website ranking?

HTTP status codes play a crucial role in search engine optimization (SEO) and website ranking. Search engine crawlers rely on status codes to understand the accessibility and relevance of web pages. Pages returning server errors or not found errors may negatively impact a website's ranking on search engine results pages (SERPs).