How do I send a POST request with PHP?

CURL-less method with PHP5:

$url = 'http://server.com/path';
$data = array('key1' => 'value1', 'key2' => 'value2');

// use key 'http' even if you send the request to https://...
$options = array(
    'http' => array(
        'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
        'method'  => 'POST',
        'content' => http_build_query($data)
    )
);
$context  = stream_context_create($options);
$result = file_get_contents($url, false, $context);
if ($result === FALSE) { /* Handle error */ }

var_dump($result);

See the PHP manual for more information on the method and how to add headers, for example:

stream_context_create: http://php.net/manual/en/function.stream-context-create.php

---

You could use cURL:

<?php
//The url you wish to send the POST request to
$url = $file_name;

//The data you want to send via POST
$fields = [
    '__VIEWSTATE '      => $state,
    '__EVENTVALIDATION' => $valid,
    'btnSubmit'         => 'Submit'
];

//url-ify the data for the POST
$fields_string = http_build_query($fields);

//open connection
$ch = curl_init();

//set the url, number of POST vars, POST data
curl_setopt($ch,CURLOPT_URL, $url);
curl_setopt($ch,CURLOPT_POST, true);
curl_setopt($ch,CURLOPT_POSTFIELDS, $fields_string);

//So that curl_exec returns the contents of the cURL; rather than echoing it
curl_setopt($ch,CURLOPT_RETURNTRANSFER, true); 

//execute post
$result = curl_exec($ch);
echo $result;
?>

---

I use the following function to post data using curl. $data is an array of fields to post (will be correctly encoded using http_build_query). The data is encoded using application/x-www-form-urlencoded.

function httpPost($url, $data)
{
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_POSTFIELDS, http_build_query($data));
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    $response = curl_exec($curl);
    curl_close($curl);
    return $response;
}

@Edward mentions that http_build_query may be omitted since curl will correctly encode array passed to CURLOPT_POSTFIELDS parameter, but be advised that in this case the data will be encoded using multipart/form-data.

I use this function with APIs that expect data to be encoded using application/x-www-form-urlencoded. That's why I use http_build_query().

---

I recommend you to use the open-source package guzzle that is fully unit tested and uses the latest coding practices.

Installing Guzzle

Go to the command line in your project folder and type in the following command (assuming you already have the package manager composer installed). If you need help how to install Composer, you should have a look here.

php composer.phar require guzzlehttp/guzzle

Using Guzzle to send a POST request

The usage of Guzzle is very straight forward as it uses a light-weight object-oriented API:

// Initialize Guzzle client
$client = new GuzzleHttp\Client();

// Create a POST request
$response = $client->request(
    'POST',
    'http://example.org/',
    [
        'form_params' => [
            'key1' => 'value1',
            'key2' => 'value2'
        ]
    ]
);

// Parse the response object, e.g. read the headers, body, etc.
$headers = $response->getHeaders();
$body = $response->getBody();

// Output headers and body for debugging purposes
var_dump($headers, $body);

---

I'd like to add some thoughts about the curl-based answer of Fred Tanrikut. I know most of them are already written in the answers above, but I think it is a good idea to show an answer that includes all of them together.

Here is the class I wrote to make HTTP-GET/POST/PUT/DELETE requests based on curl, concerning just about the response body:

class HTTPRequester {
    /**
     * @description Make HTTP-GET call
     * @param       $url
     * @param       array $params
     * @return      HTTP-Response body or an empty string if the request fails or is empty
     */
    public static function HTTPGet($url, array $params) {
        $query = http_build_query($params); 
        $ch    = curl_init($url.'?'.$query);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HEADER, false);
        $response = curl_exec($ch);
        curl_close($ch);
        return $response;
    }
    /**
     * @description Make HTTP-POST call
     * @param       $url
     * @param       array $params
     * @return      HTTP-Response body or an empty string if the request fails or is empty
     */
    public static function HTTPPost($url, array $params) {
        $query = http_build_query($params);
        $ch    = curl_init();
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HEADER, false);
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $query);
        $response = curl_exec($ch);
        curl_close($ch);
        return $response;
    }
    /**
     * @description Make HTTP-PUT call
     * @param       $url
     * @param       array $params
     * @return      HTTP-Response body or an empty string if the request fails or is empty
     */
    public static function HTTPPut($url, array $params) {
        $query = \http_build_query($params);
        $ch    = \curl_init();
        \curl_setopt($ch, \CURLOPT_RETURNTRANSFER, true);
        \curl_setopt($ch, \CURLOPT_HEADER, false);
        \curl_setopt($ch, \CURLOPT_URL, $url);
        \curl_setopt($ch, \CURLOPT_CUSTOMREQUEST, 'PUT');
        \curl_setopt($ch, \CURLOPT_POSTFIELDS, $query);
        $response = \curl_exec($ch);
        \curl_close($ch);
        return $response;
    }
    /**
     * @category Make HTTP-DELETE call
     * @param    $url
     * @param    array $params
     * @return   HTTP-Response body or an empty string if the request fails or is empty
     */
    public static function HTTPDelete($url, array $params) {
        $query = \http_build_query($params);
        $ch    = \curl_init();
        \curl_setopt($ch, \CURLOPT_RETURNTRANSFER, true);
        \curl_setopt($ch, \CURLOPT_HEADER, false);
        \curl_setopt($ch, \CURLOPT_URL, $url);
        \curl_setopt($ch, \CURLOPT_CUSTOMREQUEST, 'DELETE');
        \curl_setopt($ch, \CURLOPT_POSTFIELDS, $query);
        $response = \curl_exec($ch);
        \curl_close($ch);
        return $response;
    }
}

Improvements

Using http_build_query to get the query-string out of an request-array.(you could also use the array itself, therefore see: http://php.net/manual/en/function.curl-setopt.php)

Returning the response instead of echoing it. Btw you can avoid the returning by removing the line curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);. After that the return value is a boolean(true = request was successful otherwise an error occured) and the response is echoed. See: http://php.net/en/manual/function.curl-exec.php

Clean session closing and deletion of the curl-handler by using curl_close. See: http://php.net/manual/en/function.curl-close.php

Using boolean values for the curl_setopt function instead of using any number.(I know that any number not equal zero is also considered as true, but the usage of true generates a more readable code, but that's just my opinion)

Ability to make HTTP-PUT/DELETE calls(useful for RESTful service testing)

Example of usage

GET

$response = HTTPRequester::HTTPGet("http://localhost/service/foobar.php", array("getParam" => "foobar"));

POST

$response = HTTPRequester::HTTPPost("http://localhost/service/foobar.php", array("postParam" => "foobar"));

PUT

$response = HTTPRequester::HTTPPut("http://localhost/service/foobar.php", array("putParam" => "foobar"));

DELETE

$response = HTTPRequester::HTTPDelete("http://localhost/service/foobar.php", array("deleteParam" => "foobar"));

Testing

You can also make some cool service tests by using this simple class.

class HTTPRequesterCase extends TestCase {
    /**
     * @description test static method HTTPGet
     */
    public function testHTTPGet() {
        $requestArr = array("getLicenses" => 1);
        $url        = "http://localhost/project/req/licenseService.php";
        $this->assertEquals(HTTPRequester::HTTPGet($url, $requestArr), '[{"error":false,"val":["NONE","AGPL","GPLv3"]}]');
    }
    /**
     * @description test static method HTTPPost
     */
    public function testHTTPPost() {
        $requestArr = array("addPerson" => array("foo", "bar"));
        $url        = "http://localhost/project/req/personService.php";
        $this->assertEquals(HTTPRequester::HTTPPost($url, $requestArr), '[{"error":false}]');
    }
    /**
     * @description test static method HTTPPut
     */
    public function testHTTPPut() {
        $requestArr = array("updatePerson" => array("foo", "bar"));
        $url        = "http://localhost/project/req/personService.php";
        $this->assertEquals(HTTPRequester::HTTPPut($url, $requestArr), '[{"error":false}]');
    }
    /**
     * @description test static method HTTPDelete
     */
    public function testHTTPDelete() {
        $requestArr = array("deletePerson" => array("foo", "bar"));
        $url        = "http://localhost/project/req/personService.php";
        $this->assertEquals(HTTPRequester::HTTPDelete($url, $requestArr), '[{"error":false}]');
    }
}

---

There's another CURL method if you are going that way.

This is pretty straightforward once you get your head around the way the PHP curl extension works, combining various flags with setopt() calls. In this example I've got a variable $xml which holds the XML I have prepared to send - I'm going to post the contents of that to example's test method.

$url = 'http://api.example.com/services/xmlrpc/';
$ch = curl_init($url);

curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = curl_exec($ch);
curl_close($ch);
//process $response

First we initialised the connection, then we set some options using setopt(). These tell PHP that we are making a post request, and that we are sending some data with it, supplying the data. The CURLOPT_RETURNTRANSFER flag tells curl to give us the output as the return value of curl_exec rather than outputting it. Then we make the call and close the connection - the result is in $response.

---

If you by any chance are using Wordpress to develop your app (it's actually a convenient way to get authorization, info pages etc even for very simple stuff), you can use the following snippet:

$response = wp_remote_post( $url, array('body' => $parameters));

if ( is_wp_error( $response ) ) {
    // $response->get_error_message()
} else {
    // $response['body']
}

It uses different ways of making the actual HTTP request, depending on what is available on the web server. For more details, see the HTTP API documentation.

If you don't want to develop a custom theme or plugin to start the Wordpress engine, you can just do the following in an isolated PHP file in the wordpress root:

require_once( dirname(__FILE__) . '/wp-load.php' );

// ... your code

It won't show any theme or output any HTML, just hack away with the Wordpress APIs!

---

Another alternative of the curl-less method above is to use the native stream functions:

stream_context_create(): Creates and returns a stream context with any options supplied in options preset.

stream_get_contents(): Identical to file_get_contents(), except that stream_get_contents() operates on an already open stream resource and returns the remaining contents in a string, up to maxlength bytes and starting at the specified offset.

A POST function with these can simply be like this:

<?php

function post_request($url, array $params) {
  $query_content = http_build_query($params);
  $fp = fopen($url, 'r', FALSE, // do not use_include_path
    stream_context_create([
    'http' => [
      'header'  => [ // header array does not need '\r\n'
        'Content-type: application/x-www-form-urlencoded',
        'Content-Length: ' . strlen($query_content)
      ],
      'method'  => 'POST',
      'content' => $query_content
    ]
  ]));
  if ($fp === FALSE) {
    return json_encode(['error' => 'Failed to get contents...']);
  }
  $result = stream_get_contents($fp); // no maxlength/offset
  fclose($fp);
  return $result;
}

---

Here is using just one command without cURL. Super simple.

echo file_get_contents('https://www.server.com', false, stream_context_create([
    'http' => [
        'method' => 'POST',
        'header'  => "Content-type: application/x-www-form-urlencoded",
        'content' => http_build_query([
            'key1' => 'Hello world!', 'key2' => 'second value'
        ])
    ]
]));

---

The better way of sending GET or POST requests with PHP is as below:

<?php
    $r = new HttpRequest('http://example.com/form.php', HttpRequest::METH_POST);
    $r->setOptions(array('cookies' => array('lang' => 'de')));
    $r->addPostFields(array('user' => 'mike', 'pass' => 's3c|r3t'));

    try {
        echo $r->send()->getBody();
    } catch (HttpException $ex) {
        echo $ex;
    }
?>

The code is taken from official documentation here http://docs.php.net/manual/da/httprequest.send.php

---

Based on the main answer, here is what I use:

function do_post($url, $params) {
    $options = array(
        'http' => array(
            'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
            'method'  => 'POST',
            'content' => $params
        )
    );
    $result = file_get_contents($url, false, stream_context_create($options));
}

Example usage:

do_post('https://www.google-analytics.com/collect', 'v=1&t=pageview&tid=UA-xxxxxxx-xx&cid=abcdef...');

---

I was looking for a similar problem and found a better approach of doing this. So here it goes.

You can simply put the following line on the redirection page (say page1.php).

header("Location: URL", TRUE, 307); // Replace URL with to be redirected URL, e.g. final.php

I need this to redirect POST requests for REST API calls. This solution is able to redirect with post data as well as custom header values.

Here is the reference link.

---

[Edit]: Please ignore, not available in php now.

There is one more which you can use

<?php
$fields = array(
    'name' => 'mike',
    'pass' => 'se_ret'
);
$files = array(
    array(
        'name' => 'uimg',
        'type' => 'image/jpeg',
        'file' => './profile.jpg',
    )
);

$response = http_post_fields("http://www.example.com/", $fields, $files);
?>

Click here for details

---

Here ok with this code:

<?php
$postdata = http_build_query(
    array(
        'name' => 'Robert',
        'id' => '1'
    )
);
$opts = array('http' =>
    array(
        'method' => 'POST',
        'header' => 'Content-type: application/x-www-form-urlencoded',
        'content' => $postdata
    )
);
$context = stream_context_create($opts);
$result = file_get_contents('http://localhost:8000/api/test', false, $context);
echo $result;?>

---

Try PEAR's HTTP_Request2 package to easily send POST requests. Alternatively, you can use PHP's curl functions or use a PHP stream context.

HTTP_Request2 also makes it possible to mock out the server, so you can unit-test your code easily

---

I make a function to request a post using JSON:

const FORMAT_CONTENT_LENGTH = 'Content-Length: %d';
const FORMAT_CONTENT_TYPE = 'Content-Type: %s';

const CONTENT_TYPE_JSON = 'application/json';
/**
 * @description Make a HTTP-POST JSON call
 * @param string $url
 * @param array $params
 * @return bool|string HTTP-Response body or an empty string if the request fails or is empty
 */
function HTTPJSONPost(string $url, array $params)
{
    $content = json_encode($params);
    $response = file_get_contents($url, false, // do not use_include_path
        stream_context_create([
            'http' => [
                'method' => 'POST',
                'header' => [ // header array does not need '\r\n'
                    sprintf(FORMAT_CONTENT_TYPE, CONTENT_TYPE_JSON),
                    sprintf(FORMAT_CONTENT_LENGTH, strlen($content)),
                ],
                'content' => $content
            ]
        ])); // no maxlength/offset
    if ($response === false) {
        return json_encode(['error' => 'Failed to get contents...']);
    }

    return $response;
}

---

I prefer this one:

function curlPost($url, $data = NULL, $headers = []) {
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($ch, CURLOPT_TIMEOUT, 5); //timeout in seconds
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
    curl_setopt($ch, CURLOPT_ENCODING, 'identity');

    
    if (!empty($data)) {
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
    }

    if (!empty($headers)) {
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    }

    $response = curl_exec($ch);
    if (curl_error($ch)) {
        trigger_error('Curl Error:' . curl_error($ch));
    }

    curl_close($ch);
    return $response;
}

Usage example:

$response=curlPost("http://my.url.com", ["myField1"=>"myValue1"], ["myFitstHeaderName"=>"myFirstHeaderValue"]);

---

If you come from previous POST/GET/... you can include('fileName.php') or require('fileName.php') PHP script, in the actual php sheet. So it will continue the POST/GET/... petition will be valid inside the scope

---