HTTP Response Code Checker



When you type a URL or click a link in a web browser, the request for the page is sent to the site’s web server. The web server returns an HTTP status response code in addition to other data, usually (but not always) the requested page’s HTML source code.

Use the HTTP Response Code Checker tool to see which response code your web server is returning for a requested URL. Simply type or paste the URL in the box below, and then click Ninja Check.

Note: There may be more than one response code returned if the original URL is redirected to another URL.


The most commonly returned HTTP response codes include the following:

  • 200: The page at the URL requested was successfully processed by the web server.
  • 301: The URL requested has been permanently reassigned to another URL, and the page at that URL will be requested.
  • 302: The URL requested has been temporarily reassigned to another URL, and the page at that URL will be requested.
  • 404: The page at the URL requested couldn’t be found on the web server.
  • 503: The web server is temporarily unavailable and cannot process the URL request.

For a comprehensive list of HTTP status response codes and their definitions, explore the following links:

Note: Using the correct type of URL redirect is very important for search engine optimization (SEO) purposes. For detailed information on using URL redirects for SEO, see The Ultimate How-To Guide on 301 Redirects blog post.

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HTTP Response Code Key

1xx—Informational Responses

  • 100 Trying: extended search being performed may take a significant time so a forking proxy must send a 100 Trying response
  • 180 Ringing
  • 181 Call Is Being Forwarded
  • 182 Queued
  • 183 Session Progress

2xx—Successful Responses

  • 200 OK
  • 202 accepted: It Indicates that the request has been understood but actually can't be processed
  • 204 No Notification [RFC5839]

3xx—Redirection Responses

  • 300 Multiple Choices
  • 301 Moved Permanently
  • 302 Moved Temporarily
  • 305 Use Proxy
  • 380 Alternative Service

4xx—Client Failure Responses

  • 400 Bad Request
  • 401 Unauthorized (Used only by registrars or user agents. Proxies should use proxy authorization 407)
  • 402 Payment Required (Reserved for future use)
  • 403 Forbidden
  • 404 Not Found (User not found)
  • 405 Method Not Allowed
  • 406 Not Acceptable
  • 407 Proxy Authentication Required
  • 408 Request Timeout (Couldn't find the user in time)
  • 409 Conflict
  • 410 Gone (The user existed once, but is not available here any more.)
  • 412 Conditional Request Failed
  • 413 Request Entity Too Large
  • 414 Request-URI Too Long
  • 415 Unsupported Media Type
  • 416 Unsupported URI Scheme
  • 417 Unknown Resource-Priority
  • 420 Bad Extension (Bad SIP Protocol Extension used, not understood by the server)
  • 421 Extension Required
  • 422 Session Interval Too Small
  • 423 Interval Too Brief
  • 424 Bad Location Information
  • 428 Use Identity Header
  • 429 Provide Referrer Identity
  • 433 Anonymity Disallowed
  • 436 Bad Identity-Info
  • 437 Unsupported Certificate
  • 438 Invalid Identity Header
  • 480 Temporarily Unavailable
  • 481 Call/Transaction Does Not Exist
  • 482 Loop Detected
  • 483 Too Many Hops
  • 484 Address Incomplete
  • 485 Ambiguous
  • 486 Busy Here
  • 487 Request Terminated
  • 488 Not Acceptable Here
  • 489 Bad Event
  • 491 Request Pending
  • 493 Undecipherable (Could not decrypt S/MIME body part)
  • 494 Security Agreement Required

5xx—Server Failure Responses

  • 500 Server Internal Error
  • 501 Not Implemented: The SIP request method is not implemented here
  • 502 Bad Gateway
  • 503 Service Unavailable
  • 504 Server Time-out
  • 505 Version Not Supported: The server does not support this version of the SIP protocol
  • 513 Message Too Large
  • 580 Precondition Failure

6xx—Global Failure Responses

  • 600 Busy Everywhere
  • 603 Decline
  • 604 Does Not Exist Anywhere
  • 606 Not Acceptable