cURL

Headers Commands

Control HTTP headers for content negotiation, caching, CORS debugging, and custom API requirements. Headers are essential for proper API communication and debugging.

7 commands

Pro Tips

Use 'curl -I url' to fetch only response headers (HEAD request) — great for checking redirects and caching.

Chain multiple headers: 'curl -H "Accept: application/json" -H "X-API-Key: key" url'.

Use 'curl -D - url' to dump response headers alongside the body for debugging.

Common Mistakes

Some servers reject requests without a proper User-Agent header. Add '-A "MyApp/1.0"' if you get 403 errors.

Setting 'Content-Length' manually can cause issues. Let cURL calculate it automatically from your data.

Commands

Set Accept header

$ curl -H "Accept: application/json" https://api.example.com

Set Accept header for response type

Set Content-Type

$ curl -H "Content-Type: application/json" https://api.example.com

Set Content-Type header

Add custom header

$ curl -H "X-Custom-Header: value" https://api.example.com

Add custom header to request

Show only headers

$ curl -s -o /dev/null -D - https://example.com

Show only response headers, no body

Set Referer

$ curl -e "https://google.com" https://example.com

Set Referer header

Show response headers

$ curl -i https://api.example.com/resource

Include response headers in output

Set User-Agent

$ curl -A "Mozilla/5.0" https://example.com

Set User-Agent header