PHP: Set custom headers with cURL.

In this guide, we will show you how to set custom request headers with PHP’s cuRL extension.

We can change header values pretty easily using the CURLOPT_HTTPHEADER option.

For example, we could modify the Referer, Cookie, User-Agent or Accept-Encoding headers.

Take a look at the following cURL request:

//The URL you're sending the request to.
$url = 'http://localhost/test/file.php';

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

//Create an array of custom headers.
$customHeaders = array(
    'Accept-Encoding: gzip, deflate, br',
    'Cookie: PHPSESSID=ciqas3vp82m514iubpr1b0md3o;',

//Use the CURLOPT_HTTPHEADER option to use our
//custom headers.
curl_setopt($ch, CURLOPT_HTTPHEADER, $customHeaders);

//Set options to follow redirects and return output
//as a string.
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

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

echo $result;

In the PHP code above, we sent a GET request to a localhost URL.

We also created a PHP array called $customHeaders, which contains all of the custom headers that we want to send.

In this case, we set three custom headers using the CURLOPT_HTTPHEADER option:

  • We set the “Accept-Encoding” header to gzip, deflate and br (Brotli).
  • We provided a PHPSESSID value as the “Cookie” header.
  • Finally, we set the HTTP referer to a Google search URL. This is called referrer spoofing.

If you send this cURL request to a PHP script that prints out the $_SERVER array, you will see something like this:

Custom Headers Curl

In the screenshot above, you can see that the script has received our headers:

  • The “Accept-Encoding” header is HTTP_ACCEPT_ENCODING.
  • Cookie is HTTP_COOKIE.
  • Referer is HTTP_REFERER.

Pretty simple!