cURL Command Generator & Builder Online

Generate cURL commands instantly from JSON data for API testing. Build HTTP requests with custom methods, headers, and authentication. Free, fast, and 100% client-side processing.

JSON Formatter API Tester

Request Configuration

HTTP Method

API Endpoint URL

Request Headers (one per line)

Include Headers

Pretty Print JSON

JSON Request Body

Generated cURL Command

cURL command will appear here...

Quick Tips

Using cURL in Terminal:

• Paste the command and press Enter
• Add -v for verbose output
• Add -s for silent mode

Common Use Cases:

• Test REST API endpoints
• Debug authentication issues
• Automate with shell scripts

How to Generate cURL Commands

Build cURL commands for API testing in just a few simple steps.

1. Enter URL

Paste your API endpoint URL

2. Select Method

Choose GET, POST, PUT, PATCH, or DELETE

3. Add Headers

Set Content-Type, Auth, and custom headers

4. Paste JSON

Add your JSON request body

5. Generate

Copy cURL command and test in terminal

What is cURL?

cURL (Client URL) is a powerful command-line tool and library for transferring data with URLs. Created by Daniel Stenberg in 1997, it has become one of the most essential tools for developers, system administrators, and API testers worldwide.

cURL supports over 25 protocols including HTTP, HTTPS, FTP, FTPS, SMTP, and more. For web developers, it's primarily used to make HTTP requests to test APIs, download files, and debug web services directly from the terminal.

Why Use cURL for API Testing?

✓Universal: Available on Linux, macOS, Windows (via WSL or Git Bash), and most development environments
✓Quick Testing: Test API endpoints instantly without opening Postman or other heavy applications
✓Scriptable: Automate API tests by including cURL commands in shell scripts and CI/CD pipelines
✓Documentation: Share cURL commands in documentation so others can easily reproduce API calls
✓Debugging: Quickly identify API issues by testing raw requests with verbose output (-v flag)

Common cURL Command Examples

GET Request (Retrieve Data)

curl -X GET "https://api.example.com/users" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json"

POST Request (Create Data)

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

PUT Request (Update Data)

curl -X PUT "https://api.example.com/users/123" \
  -H "Content-Type: application/json" \
  -d '{"name": "John Updated", "email": "john.new@example.com"}'

DELETE Request (Remove Data)

curl -X DELETE "https://api.example.com/users/123" \
  -H "Authorization: Bearer YOUR_TOKEN"

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Frequently Asked Questions

What is a cURL command?

cURL (Client URL) is a command-line tool and library used to transfer data with URLs. A cURL command allows you to make HTTP requests directly from your terminal or command prompt. It's widely used by developers for testing APIs, downloading files, and debugging web services. cURL supports various protocols including HTTP, HTTPS, FTP, and more.

How do I generate a cURL command from JSON?

To generate a cURL command from JSON: (1) Paste your JSON data into our generator, (2) Select the HTTP method (GET, POST, PUT, PATCH, DELETE), (3) Enter the API endpoint URL, (4) Add any required headers (like Content-Type: application/json or Authorization), (5) Click generate and copy the cURL command. You can then paste it into your terminal to test the API request.

What HTTP methods does the cURL generator support?

Our cURL generator supports all common HTTP methods: GET (retrieve data), POST (send/create data), PUT (update/replace data), PATCH (partial update), and DELETE (remove data). Each method generates the appropriate cURL syntax with the -X flag and properly formatted request body for methods that send data.

Can I convert cURL commands to code in other languages?

Currently, our tool generates cURL commands from JSON data. You can copy the generated cURL command and use online converters to transform it into code for JavaScript (fetch/axios), Python (requests), PHP, Go, and other languages. We're planning to add multi-language export in a future update.

Is the cURL generator free to use?

Yes, our cURL command generator is 100% free with no usage limits, no registration required, and no hidden costs. All processing happens in your browser for maximum privacy and speed. You can generate unlimited cURL commands for testing your APIs.