HTTP Status Code Reference Guide

Search and browse standardized RFC server status codes, classes, and developer definitions with live response headers

Selected Code InfoRFC 9110, 15.3.1
200 OK

Standard response for successful HTTP requests. The actual response will depend on the request method used.

Illustrative HTTP Headers

2. History Log Save Name

100 Continue

The server has received the request headers and the client should proceed to send the request body.

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101 Switching Protocols

The requester has asked the server to switch protocols and the server has agreed to do so.

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200 OK

Standard response for successful HTTP requests. The actual response will depend on the request method used.

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201 Created

The request has been fulfilled, resulting in the creation of a new resource.

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202 Accepted

The request has been accepted for processing, but the processing has not been completed.

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204 No Content

The server successfully processed the request and is not returning any content.

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206 Partial Content

The server is delivering only part of the resource due to a range header sent by the client.

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301 Moved Permanently

This and all future requests should be directed to the given URI.

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302 Found

Tells the client to look at another URL, but future requests should still use the original URI.

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304 Not Modified

Indicates that the resource has not been modified since the version specified by the request headers.

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307 Temporary Redirect

The request should be repeated with another URI; however, future requests should still use the original URI.

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308 Permanent Redirect

The request and all future requests should be repeated using another URI.

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400 Bad Request

The server cannot or will not process the request due to an apparent client error.

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401 Unauthorized

Similar to 403 Forbidden, but specifically for use when authentication is required and has failed.

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403 Forbidden

The request was valid, but the server is refusing action. The user might not have the necessary permissions.

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404 Not Found

The requested resource could not be found but may be available in the future.

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405 Method Not Allowed

A request method is not supported for the requested resource.

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409 Conflict

Indicates that the request could not be processed because of conflict in the current state of the resource.

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429 Too Many Requests

The user has sent too many requests in a given amount of time. Intended for rate-limiting.

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500 Internal Server Error

A generic error message, given when an unexpected condition was encountered on the server.

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502 Bad Gateway

The server was acting as a gateway or proxy and received an invalid response from the upstream server.

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503 Service Unavailable

The server is temporarily overloaded or down for maintenance. Generally, this is a temporary state.

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504 Gateway Timeout

The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.

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Standard Protocol RFC 9110 HTTP/1.1 & HTTP/2
Execution Sandbox 100% Secure Client-Side

Web Protocols and Server Hygiene: Standard HTTP Status Codes, RFC Specifications, and HTTP Header Mocks

In modern backend application development, client-server communications, and API lifecycle architectures, server status codes form the core grammar of the web. Whenever a browser requests an endpoint, the server responds with a specific numeric status code. This code indicates whether the request was successful, redirected, blocked, or encountered a database exception. An HTTP Status Code Reference Guide provides a searchable database of standard codes, RFC definitions, and raw header structures.

Deconstructing HTTP Response Classes and RFC 9110 Specifications

HTTP status codes are standardized under the Internet Engineering Task Force (IETF) RFC 9110 guidelines. These codes are divided into five distinct classes:

  • 1xx (Informational): Temporary, transitional status reports (e.g. 101 Switching Protocols).
  • 2xx (Success): Confirmations of successful actions (e.g. 200 OK, 201 Created).
  • 3xx (Redirection): Instructions for client redirection to another URL (e.g. 301 Moved, 304 Not Modified).
  • 4xx (Client Error): Client-side issues such as invalid query syntax or missing credentials (e.g. 401 Unauthorized, 404 Not Found).
  • 5xx (Server Error): Internal server-side issues or gateway failures (e.g. 500 Server Error, 502 Bad Gateway).

Real-Time Header Mocks and Security Benefits

Our guide provides an interactive interface displaying illustrative, raw HTTP response headers for each selected status code. This helps developers visualize exactly how these codes are transmitted across network sockets.

You can also save your inspected configurations with custom separate names (such as "REST API 404 Not Found Reference") directly in your secure local History Log, streamlining your development audits. Because all search, filtering, and header formatting operations run completely client-side in your browser's private memory sandbox, your intellectual designs and queries remain entirely secure.

100% Private Client-Side Reference Sandbox

Our 100% Client-Side Privacy standard guarantees that your searched status codes, custom names, and history logs are processed entirely within your local device's memory. No external tracking logs or analytical database APIs are ever initialized, protecting your operational parameters.

📄 Web Protocol Best Practice

Always return the most specific and semantic HTTP status code possible from your server. For example, use a `201 Created` instead of a generic `200 OK` when an entity has been successfully generated. This helps client-side routers and crawlers understand response states without parsing nested JSON bodies. Save your custom styled presets directly to the local History Log.