Curl - Display Request and Response Headers

In default mode, curl doesn’t display request or response headers, only displaying the HTML contents.

To display both request and response headers, we can use the verbose mode curl -v or curl -verbose. In the resulting output:

• The lines beginning with > indicate request headers.
• The lines beginning with < indicate response headers.
• (The lines beginning with * indicate additional information.)

Let’s try curl -v http://codeahoy.com to print request and response headers. In the image below, the request and response headers are highlighted.

Complete example:

curl -v http://codeahoy.com

*   Trying 2606:4700:3032::ac43:d1bc...
* TCP_NODELAY set
* Connected to codeahoy.com (2606:4700:3032::ac43:d1bc) port 80 (#0)
> GET / HTTP/1.1
> Host: codeahoy.com
> User-Agent: curl/7.64.1
> Accept: */*
> 
< HTTP/1.1 301 Moved Permanently
< Date: Sun, 22 Aug 2021 18:57:16 GMT
< Transfer-Encoding: chunked
< Connection: keep-alive
< Cache-Control: max-age=3600
< Expires: Sun, 22 Aug 2021 19:57:16 GMT
< Location: https://codeahoy.com/
< Report-To: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=s7X0EJLhIVF8i%2Bkkxxzl1URcpPF65SmKK%2BRthSOgOcbA9xnyChBwSpVYL3eIjk369OlW52rawLwH9DR268EanSOrK9QAMTc7aQ35%2Bntje3X7QSFjeiXLmI2P3JkiRZMl1XqA%2Bm%2BYEaSySFM%3D"}],"group":"cf-nel","max_age":604800}
< NEL: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
< Server: cloudflare
< CF-RAY: 682e536f49440d44-LAX
< alt-svc: h3-27=":443"; ma=86400, h3-28=":443"; ma=86400, h3-29=":443"; ma=86400, h3=":443"; ma=86400
< 
* Connection #0 to host codeahoy.com left intact
* Closing connection 0

Display only Response Headers in curl

If you want to display only the response headers, you can use the --head flag.

curl --head http://codeahoy.com       

HTTP/1.1 301 Moved Permanently
Date: Sun, 22 Aug 2021 19:14:41 GMT
Connection: keep-alive
Cache-Control: max-age=3600
Expires: Sun, 22 Aug 2021 20:14:41 GMT
Location: https://codeahoy.com/
Report-To: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=FJzR6TegRQYBvzipX6RglYE4NgeOvqiNS0%2Faf0Z7pLe0YDku7Gk7xvKgB8RRpvF9vAO81saiqA5PDCoY2Fzz%2BqSY9yQsbOdKjmFVVdYK4ccyYFpoKOoErreL9cqnXFo36%2FYaZcDFDheb%2FU4%3D"}],"group":"cf-nel","max_age":604800}
NEL: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
Server: cloudflare
CF-RAY: 682e6cf26fe7094c-SEA
alt-svc: h3-27=":443"; ma=86400, h3-28=":443"; ma=86400, h3-29=":443"; ma=86400, h3=":443"; ma=86400

---

Here’s an alternate way to --head for displaying response headers:

curl -s -D - -o /dev/null http://codeahoy.com

Note:

• -s hides the progress bar
• -D - dump headers to stdout indicated by -
• -o /dev/null send output (HTML) to /dev/null essentially ignoring it

Example:

curl -s -D - -o /dev/null http://codeahoy.com

HTTP/1.1 301 Moved Permanently
Date: Sun, 22 Aug 2021 19:10:49 GMT
Transfer-Encoding: chunked
Connection: keep-alive
Cache-Control: max-age=3600
Expires: Sun, 22 Aug 2021 20:10:49 GMT
Location: https://codeahoy.com/
Report-To: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=7QSrtkFxzkNpCbvMNNqdiuS%2B8II41I%2F7AJRdHwqV49DiyuAyYgTSiV0ceaXx2Es0SJ1XcLmdz9xd6lkQqgl0oe7npIE3QokSgpf86ueyosfjFWHVJcCg5OpIngOkdb12NKz5hOTDbxNTsKg%3D"}],"group":"cf-nel","max_age":604800}
NEL: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
Server: cloudflare
CF-RAY: 682e67499a52088d-SEA
alt-svc: h3-27=":443"; ma=86400, h3-28=":443"; ma=86400, h3-29=":443"; ma=86400, h3=":443"; ma=86400