http not found code code example

Example 1: http response status codes

HTTP response status codes

HTTP response status codes indicate whether a specific HTTP request has been successfully completed. 
Responses are grouped in five classes:

1. Informational responses (100–199)
2. Successful responses (200–299)
3. Redirects (300–399)
4. Client errors (400–499)
5. Server errors (500–599)

1. Information responses
    a. 100 Continue
    b. 101 Switching Protocol
    c. 102 Processing (WebDAV)
    d. 103 Early Hints

2. Successful responses
    a. 200 OK
    b. 201 Created
    c. 202 Accepted
    d. 203 Non-Authoritative Information
    e. 204 No Content
    f. 205 Reset Content
    g. 206 Partial Content
    h. 207 Multi-Status (WebDAV)
    i. 208 Already Reported (WebDAV)
    j. 226 IM Used (HTTP Delta encoding)

3. Redirection messages
    a. 300 Multiple Choice
    b. 301 Moved Permanently
    c. 302 Found
    d. 303 See Other
    e. 304 Not Modified
    f. 305 Use Proxy
    g. 306 unused
    h. 307 Temporary Redirect
    i. 308 Permanent Redirect

4. Client error responses
    a. 400 Bad Request
    b. 401 Unauthorized
    c. 402 Payment Required 
    d. 403 Forbidden
    e. 404 Not Found
    f. 405 Method Not Allowed
    g. 406 Not Acceptable
    h. 407 Proxy Authentication Required
    i. 408 Request Timeout
    j. 409 Conflict
    k. 410 Gone
    l. 411 Length Required
    m. 412 Precondition Failed
    n. 413 Payload Too Large
    o. 414 URI Too Long
    p. 415 Unsupported Media Type
    q. 416 Range Not Satisfiable
    r. 417 Expectation Failed
    s. 418 I'm a teapot
    t. 421 Misdirected Request
    u. 425 Too Early 
    v. 426 Upgrade Required
    w. 428 Precondition Required
    x. 429 Too Many Requests
    y. 431 Request Header Fields Too Large
    z. 451 Unavailable For Legal Reasons

5. Server error responses
    a. 500 Internal Server Error
    b. 501 Not Implemented
    c. 502 Bad Gateway
    d. 503 Service Unavailable
    e. 504 Gateway Timeout
    f. 505 HTTP Version Not Supported
    g. 506 Variant Also Negotiates
    h. 507 Insufficient Storage (WebDAV)
    i. 508 Loop Detected (WebDAV)
    j. 510 Not Extended
    k. 511 Network Authentication Required

Example 2: http status codes

Some important http status codes are:
200: The one you will mostly want to get. Succesful transfer
301: Moved Permanently. 300 defines Redirections
404: Not found. 400: bad requests as 401 Unauthorized and 403 Forbidden.
502: Bad Gateway. 500 defines Internal Server Errors.

Example 3: 200 error code

The HTTP 200 OK success status response code indicates that the request has succeeded. A 200 response is cacheable by default. The meaning of a success depends on the HTTP request method: GET : The resource has been fetched and is transmitted in the message body.

from developer.mozilla.org

Example 4: web http code for not found

Note: The existence of the 503 status code does not imply that a
      server must use it when becoming overloaded. Some servers may wish
      to simply refuse the connection.