<?php
$html = "<div><h2>Hello world<h2><p>It's 7Am where I live<p><div>";
$dom = new DOMDocument();
$dom->loadHTML('<root>' . $html . '</root>', LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);
$xpath = new DOMXPath($dom);
foreach( $xpath->query('//*[not(node())]') as $node ) {
$node->parentNode->removeChild($node);
}
echo substr($dom->saveHTML(), 6, -8);
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