How do I send a POST request with JSON using curl?

Use the -X POST flag, -H "Content-Type: application/json" header, and -d flag with your JSON body. Example: curl -X POST -H "Content-Type: application/json" -d '{"key":"value"}' https://api.example.com/endpoint. Our builder generates this automatically when you select POST and enter a body.

How do I add Bearer token authentication to a curl command?

Add an Authorization header with the value "Bearer YOUR_TOKEN". In curl: -H "Authorization: Bearer your-token-here". In our builder, add a header with key "Authorization" and value "Bearer your-token". This works for most REST APIs including GitHub, Stripe, and custom JWTs.

What does the -k flag do in curl?

The -k or --insecure flag tells curl to skip SSL certificate verification. Use this only in development or when testing against servers with self-signed certificates. Never use -k in production scripts as it makes your requests vulnerable to man-in-the-middle attacks.

How do I follow redirects in curl?

Use the -L or --location flag to tell curl to follow HTTP redirects (301, 302, 307). Without this flag, curl stops at the first redirect response. Our builder enables -L by default as most API calls benefit from following redirects.

How do I save curl output to a file?

Add -o filename.json to save the response to a file, or -O to save with the remote filename. Example: curl -o response.json https://api.example.com/data. For large downloads, combine with -# to show a progress bar instead of transfer stats.

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Curl Command Builder

Build curl commands visually. Set method, URL, headers, auth, and request body — get a ready-to-run curl command. Free online curl builder for developers and API testing.

Headers

Basic Auth (user:pass)

-v (verbose)-k (insecure)-L (follow redirects)-s (silent)

Generated curl command

curl \
  -L \
  -X GET \
  -H 'Content-Type: application/json' \
  'https://api.example.com/endpoint'

About This Tool

Build curl commands visually without memorizing flags and syntax. Select your HTTP method (GET, POST, PUT, PATCH, DELETE), enter the URL, add custom headers, set basic auth credentials, and paste a request body. The builder generates a properly formatted, ready-to-run curl command with correct escaping. Copy and paste directly into your terminal. Perfect for API testing, documentation, debugging, and sharing reproducible API requests with teammates.