JSFiddle - React, Tailwind, and code Playground

HTML

<a href="http://example.com">Example external URL</a>
<a href="/">Example internal URL</a>

JavaScript

var links = document.links;

for (var i = 0, linksLength = links.length; i < linksLength; i++) {

    if (links[i].hostname != window.location.hostname) {
        links[i].target = '_blank';
    }

}