To send a curl post request, we can use the following syntax:
curl -X POST \
-H "Headers" \
-d "Body" \
https://httpbin.dev/post
This snippet shows the basic elements of a curl post data request:
-X
: Specifies the request HTTP method, POST in this case.
-H
: For adding request headers, which are often required for POST requests.
-d
: For adding the cURL post body, which is where your payload goes (JSON, XML, or form data).
Common cURL POST Request Examples
Let's go through some typical use cases for sending a curl post request.
cURL POST Request with JSON
To pass a JSON body in a cURL POST request with JSON, use the -d option followed by the data object:
curl -X POST -H "Content-Type: application/json" -d '{"key1": "value1", "key2": "value2"}' https://httpbin.dev/post
Here, we modify the request Content-Type
header and include the cURL request body in JSON format. The server responds with the parsed request:
{
"args": {},
"headers": {
....
"Content-Type": [
"application/json"
],
},
"method": "POST",
"data": "{\"key1\": \"value1\", \"key2\": \"value2\"}",
"json": {
"key1": "value1",
"key2": "value2"
}
}
cURL POST Request with XML
You can also send a cURL POST request with XML by changing the header and body format:
curl -X POST \
-H "Content-Type: application/xml"
-d "<?xml version="1.0" encoding="UTF-8"?><product><id>1</id><name type="title">Box of Chocolate Candy</name></product>"
https://httpbin.dev/post
This approach is common for SOAP-based or legacy APIs that require XML payloads.
Sending Files with cURL POST
To make cURL POST files, we use the -F
flag to send file data as multipart/form-data:
curl -X POST -F "file=@/file/path/file.img" https://httpbin.dev/post
Note: If you're uploading multiple files, use multiple -F
flags. This is useful for form-based file upload endpoints.
Sending Form POST Requests
Form POST requests are commonly required to retrieve tokens or data behind forms. Let's replicate this form example using cURL POST requests:
curl -X POST \
-d 'custname=Scrapfly&custtel=&custemail=&size=small&topping=cheese&delivery=13%3A45&comments=' \
https://httpbin.dev/post
This is especially useful when interacting with APIs or web apps that use forms to receive input.
Authenticate cURL POST Requests
Let's make cURL POST requests support basic HTTP authentication. For this, we can use the basic
option:
curl -X POST --user user:passwd --basic https://httpbin.dev/basic-auth/user/passwd
The response of the above cURL request indicates that it's successfully authenticated:
{
"authorized": true,
"user": "user"
}
For further details on different mechanisms for handling authentication with cURL requests, refer to our dedicated guide.
Further cURL Options
Sending cURL POST requests often require additional configuration for the request. Here are additional cURL arguments and their usage:
Argument | Full Option | Description |
---|---|---|
-x | --proxy | Use proxy with cURL, either as HTTP or SOCKS |
-Z | --parallel | Send multiple cURL requests in parallel |
-L | --location | Make cURL follow request redirects |
-O | --output | Save the response binary data to a local directory |
-I | --head | Use the request HEAD HTTP method |
-b | --cookie | Add request cookies |
-v | --verbose | Sends the request in verbose mode, which include further debugging details |
-k | --insecure | Skip SSL verification for HTTPs connection |
For further details on sending requests with cURL, refer to our dedicated guide.
How to Use cURL For Web Scraping
In this article, we'll go over a step-by-step guide on sending and configuring HTTP requests with cURL. We'll also explore advanced usages of cURL for web scraping, such as scraping dynamic pages and avoiding getting blocked.