--user-agent

Specify the User-Agent string to send to the HTTP server. To encode blanks in the string, surround the string with single quote marks. This header can also be set with the --header or the --proxy-header options.

If you give an empty argument to --user-agent (""), it removes the header completely from the request. If you prefer a blank header, you can set it to a single space (" ").

By default, curl uses curl/VERSION, such as User-Agent: curl/%VERSION.