{
  "name": "HTTP status codes",
  "description": "HTTP status codes with plain-English summaries, grouped by class.",
  "url": "https://computerscience.co.uk/reference/http-status-codes/",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "computerscience.co.uk",
  "generated": "2026-07-21T09:38:33.884Z",
  "lastReviewed": "2026-07-10",
  "sources": [
    {
      "title": "RFC 9110: HTTP Semantics (status codes)",
      "url": "https://www.rfc-editor.org/rfc/rfc9110#name-status-codes"
    },
    {
      "title": "HTTP response status codes, MDN",
      "url": "https://developer.mozilla.org/en-US/docs/Web/HTTP/Status"
    }
  ],
  "categories": {
    "1xx": "Informational: the request was received and the process is continuing.",
    "2xx": "Success: the request was received, understood and accepted.",
    "3xx": "Redirection: further action is needed to complete the request.",
    "4xx": "Client error: the request has a problem the client must fix.",
    "5xx": "Server error: the server failed to fulfil a valid request."
  },
  "count": 31,
  "liveTester": "https://computerscience.co.uk/status/{code}",
  "statusCodes": [
    {
      "code": 100,
      "text": "Continue",
      "category": "1xx",
      "summary": "The client should continue with its request.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/100"
    },
    {
      "code": 101,
      "text": "Switching Protocols",
      "category": "1xx",
      "summary": "The server is switching protocols as requested.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/101"
    },
    {
      "code": 103,
      "text": "Early Hints",
      "category": "1xx",
      "summary": "Preliminary headers sent while the response is prepared.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/103"
    },
    {
      "code": 200,
      "text": "OK",
      "category": "2xx",
      "summary": "The request succeeded. The most common status code.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/200"
    },
    {
      "code": 201,
      "text": "Created",
      "category": "2xx",
      "summary": "The request succeeded and a new resource was created.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/201"
    },
    {
      "code": 202,
      "text": "Accepted",
      "category": "2xx",
      "summary": "The request was accepted but not yet processed.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/202"
    },
    {
      "code": 204,
      "text": "No Content",
      "category": "2xx",
      "summary": "Success, but there is no body to return.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/204"
    },
    {
      "code": 206,
      "text": "Partial Content",
      "category": "2xx",
      "summary": "Part of the resource is returned, used for range requests.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/206"
    },
    {
      "code": 301,
      "text": "Moved Permanently",
      "category": "3xx",
      "summary": "The resource has a new permanent URL.",
      "detailed": true,
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/301/",
      "tryIt": "https://computerscience.co.uk/status/301"
    },
    {
      "code": 302,
      "text": "Found",
      "category": "3xx",
      "summary": "The resource is temporarily at a different URL.",
      "detailed": true,
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/302/",
      "tryIt": "https://computerscience.co.uk/status/302"
    },
    {
      "code": 304,
      "text": "Not Modified",
      "category": "3xx",
      "summary": "The cached copy is still valid, so nothing is sent.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/304"
    },
    {
      "code": 307,
      "text": "Temporary Redirect",
      "category": "3xx",
      "summary": "Temporary redirect that keeps the request method.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/307"
    },
    {
      "code": 308,
      "text": "Permanent Redirect",
      "category": "3xx",
      "summary": "Permanent redirect that keeps the request method.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/308"
    },
    {
      "code": 400,
      "text": "Bad Request",
      "category": "4xx",
      "summary": "The server cannot understand the request.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/400"
    },
    {
      "code": 401,
      "text": "Unauthorized",
      "category": "4xx",
      "summary": "Authentication is required and has failed or is missing.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/401"
    },
    {
      "code": 402,
      "text": "Payment Required",
      "category": "4xx",
      "summary": "Reserved for payment. Newly relevant for paid APIs and AI agents.",
      "detailed": true,
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/402/",
      "tryIt": "https://computerscience.co.uk/status/402"
    },
    {
      "code": 403,
      "text": "Forbidden",
      "category": "4xx",
      "summary": "The server understood the request but refuses to authorise it.",
      "detailed": true,
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/403/",
      "tryIt": "https://computerscience.co.uk/status/403"
    },
    {
      "code": 404,
      "text": "Not Found",
      "category": "4xx",
      "summary": "The server cannot find the requested resource.",
      "detailed": true,
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/404/",
      "tryIt": "https://computerscience.co.uk/status/404"
    },
    {
      "code": 405,
      "text": "Method Not Allowed",
      "category": "4xx",
      "summary": "The request method is not supported for this resource.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/405"
    },
    {
      "code": 408,
      "text": "Request Timeout",
      "category": "4xx",
      "summary": "The server timed out waiting for the request.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/408"
    },
    {
      "code": 409,
      "text": "Conflict",
      "category": "4xx",
      "summary": "The request conflicts with the current state of the resource.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/409"
    },
    {
      "code": 410,
      "text": "Gone",
      "category": "4xx",
      "summary": "The resource is permanently gone with no forwarding address.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/410"
    },
    {
      "code": 418,
      "text": "I'm a Teapot",
      "category": "4xx",
      "summary": "An April Fools joke from 1998 that became a real, beloved code.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/418"
    },
    {
      "code": 422,
      "text": "Unprocessable Content",
      "category": "4xx",
      "summary": "The request is well formed but semantically invalid.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/422"
    },
    {
      "code": 429,
      "text": "Too Many Requests",
      "category": "4xx",
      "summary": "The client has sent too many requests in a given time. Central to rate limiting.",
      "detailed": true,
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/429/",
      "tryIt": "https://computerscience.co.uk/status/429"
    },
    {
      "code": 451,
      "text": "Unavailable For Legal Reasons",
      "category": "4xx",
      "summary": "The resource is blocked for legal reasons.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/451"
    },
    {
      "code": 500,
      "text": "Internal Server Error",
      "category": "5xx",
      "summary": "A generic error: something went wrong on the server.",
      "detailed": true,
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/500/",
      "tryIt": "https://computerscience.co.uk/status/500"
    },
    {
      "code": 501,
      "text": "Not Implemented",
      "category": "5xx",
      "summary": "The server does not support the functionality required.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/501"
    },
    {
      "code": 502,
      "text": "Bad Gateway",
      "category": "5xx",
      "summary": "A server acting as a gateway got an invalid response upstream.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/502"
    },
    {
      "code": 503,
      "text": "Service Unavailable",
      "category": "5xx",
      "summary": "The server is temporarily unable to handle the request.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/503"
    },
    {
      "code": 504,
      "text": "Gateway Timeout",
      "category": "5xx",
      "summary": "A gateway server did not get a response in time.",
      "docsUrl": "https://computerscience.co.uk/reference/http-status-codes/",
      "tryIt": "https://computerscience.co.uk/status/504"
    }
  ]
}