Shodan also keeps track of the ALPN negotation results, see the &quot;Negotiated HTTP Versions&quot; chart: <a href="https:&#x2F;&#x2F;www.shodan.io&#x2F;report&#x2F;tbi6kDZa" rel="nofollow">https:&#x2F;&#x2F;www.shodan.io&#x2F;report&#x2F;tbi6kDZa</a>