InternetCheckConnection function

Allows an application to check if a connection to the Internet can be established.


BOOL InternetCheckConnection(
  _In_ LPCTSTR lpszUrl,
  _In_ DWORD   dwFlags,
  _In_ DWORD   dwReserved


lpszUrl [in]

Pointer to a null-terminated string that specifies the URL to use to check the connection. This value can be NULL.

dwFlags [in]

Options. FLAG_ICC_FORCE_CONNECTION is the only flag that is currently available. If this flag is set, it forces a connection. A sockets connection is attempted in the following order:

  • If lpszUrl is non-NULL, the host value is extracted from it and used to ping that specific host.
  • If lpszUrl is NULL and there is an entry in the internal server database for the nearest server, the host value is extracted from the entry and used to ping that server.
dwReserved [in]

This parameter is reserved and must be 0.

Return value

Returns TRUE if a connection is made successfully, or FALSE otherwise. Use GetLastError to retrieve the error code. ERROR_NOT_CONNECTED is returned by GetLastError if a connection cannot be made or if the sockets database is unconditionally offline.


Note  WinINet does not support server implementations. In addition, it should not be used from a service. For server implementations or services use Microsoft Windows HTTP Services (WinHTTP).


Minimum supported client

Windows 2000 Professional [desktop apps only]

Minimum supported server

Windows 2000 Server [desktop apps only]







Unicode and ANSI names

InternetCheckConnectionW (Unicode) and InternetCheckConnectionA (ANSI)

See also

Enabling Internet Functionality
WinINet Functions