How to Properly Close a cURL Session in PHP Using curl_close()

cURL (Client URL Library) is a PHP extension that enables sending and receiving HTTP requests, offering features such as POST/GET requests, custom headers, and cookie handling. After completing a cURL request, the curl_close() function should be called to close the session and free resources.

The syntax of curl_close() is:

curl_close(resource $ch): void

Here $ch is a cURL handle created by curl_init() , representing an active cURL session. Calling curl_close($ch) terminates that session and releases associated resources.

Example usage:

// Create a cURL handle
$ch = curl_init();

// Set cURL options
curl_setopt($ch, CURLOPT_URL, "https://www.example.com");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// Execute the cURL request
$result = curl_exec($ch);

// Close the cURL session
curl_close($ch);

In the example, we first create a handle with curl_init() , set the target URL and request to return the response as a string, execute the request with curl_exec() , and finally close the session using curl_close() .

Closing a cURL session provides several advantages:

Resource savings: network connections and related resources are released, preventing leaks.

Performance improvement: freeing request‑related resources reduces server load.

Memory release: variables and caches tied to the handle are destroyed, freeing memory.

Note that once a cURL session is closed, the handle cannot be reused; a new handle must be created for subsequent requests.

Summary

The curl_close() function is the PHP method for terminating a cURL session. Using it after each request conserves resources, boosts performance, and releases memory, ensuring robust and efficient backend code.