Flag guide

What does `curl -d` mean?

-d (long form: --data) sends data in the request body. It automatically sets the HTTP method to POST if you haven't set it explicitly with -X.

Send JSON

curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d '{"name":"Alex","email":"alex@example.com"}'

Send form data

curl -X POST https://api.example.com/login \
  -d "username=alex&password=secret"

Send a file

curl -X POST https://api.example.com/upload \
  --data-binary @report.json

Paste any curl into curlwtf.com to get a plain-English explanation of what the -d data contains and what it does.

What does curl -d mean?