HTTP Header Lookup tool allows you to check the HTTP headers that the web server returns when requesting a URL. It can show the HTTP status code, web server information, content type, content encoding, and other useful information.
The common HTTP status code:
- 200 OK:The request was successful, and the response includes the requested content.
- 301: Moved Permanently: The requested content is at another URL (specified in the Location header). Replacing the link with the new URL will improve performance.
- 302: Found: Content is temporarily located at the URL specified in the Location header.
- 303: See other: Content is located at the URL specified in the Location header. It has to be retrieved by using a GET method.
- 307: Temporary Redirect:Content is temporarily located at the URL specified in the Location header.
- 401: Unauthorized:Authentication is required to access the content.
- 403 Forbidden: Access is forbidden.
- 404: Not found:Resource was not found, or you do not have access to it.
- 405: Method not allowed: The specified HTTP method is not allowed to use. The Allow header will show the methods that you can use.
- 410: Gone:This is similar to 404, but used only when resource will not be found for good. The content is not only unavailable, but also the forwarding address is not specified.
- 500: Internal server error: There is a problem with the web server, and your request was not handled.
- 503: Service unavailable:The URL is temporarily unavailable.(Because of the overload or the maintenance)