How to debug url request

Using cURL

$ curl -L -I -v fedex.com

Which -L makes it follow redirections, otherwise you can only reach the 301 page.

-I can hide all response body, which is very very verbose.

-v makes the progress talkative, shows details of this request including DNS CA and so on.

or you can:

$ curl -L -s -o /dev/null -v fedex.com

Which send the response body output to the hell.