Asynchronous php loop - php

Question

I'm building a site where I have a json array of URL's, I use these urls to parse the meta data to display on the site. I want to show a thumbnail image, title and description. The issue that I've found is that it takes almost 10 seconds to get the data ready to be displayed in the site.
My question I want to ask is this: How should I go about to make it asynchronous, so that the loading time is drastically reduced. Does anyone have suggestions for this?
$jsonData = file_get_contents("data.json");
$json = json_decode($jsonData, true);
<div class="container" id="content">
<?php
$jsonData = file_get_contents("data.json");
$json = json_decode($jsonData, true);
function file_get_contents_curl($url){
$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$data = curl_exec($ch);
curl_close($ch);
return $data;
}
foreach ($json['posts'] as $post){
$html = file_get_contents_curl($post['url']);
//parsing begins here:
$doc = new DOMDocument();
#$doc->loadHTML($html);
$nodes = $doc->getElementsByTagName('title');
//get and display what you need:
$title = $nodes->item(0)->nodeValue;
$metas = $doc->getElementsByTagName('meta');
for ($i = 0; $i < $metas->length; $i++)
{
$meta = $metas->item($i);
if($meta->getAttribute('property')=='og:image'){
$image = $meta->getAttribute('content');}
if($meta->getAttribute('name') == 'description')
$description = $meta->getAttribute('content');
if($meta->getAttribute('name') == 'keywords')
$keywords = $meta->getAttribute('content');
}
$output = "<a href='$post[url]'><br>";
$output .= "<div class='thumbnail'><br>";
$output .= "<img src='$image'><br>";
$output .= "<p class='article-headline'>$title</p><br>";
$output .= "<p class='article-excerpt'>$description</p><br>";
$output .= "</div></a>";
echo $output;
}
?>
</div>
my data.json file looks like this but with about 16 urls. The idea is that it's supposed to be able to handle an array with alot more URL's:
{
"posts": [
{
"url":"https://medium.com/s/story/the-absurdity-of-student-loan-debt-fb61fdca7d8c"
},
{
"url":"https://medium.com/s/in-defense-of-the-worst-human-emotions/jealousy-is-a-brat-eed054493965"
},
{
"url":"https://medium.com/swlh/chatbots-were-the-next-big-thing-what-happened-5fc49dd6fa61"
},
{
"url":"https://medium.com/s/trustissues/my-so-called-millennial-entitlement-9be84343c713"
}
]
}