JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. <a href="http://...">Nullam elit</a> risus, blandit eu pretium quis, porta a odio. Nullam rhoncus, lectus ac faucibus rutrum, dui massa dignissim nisi, ut auctor ipsum mi eget justo. Nam nec leo eget neque viverra pulvinar a aliquet lorem. Suspendisse sodales odio pretium lacinia pharetra. Donec at sapien a eros fermentum vehicula at sagittis felis. Proin eu venenatis leo. Phasellus volutpat auctor leo, ac dignissim risus fringilla eget.</p>
</div>

JavaScript

function replaceToLink(str,href) {
    $('.linkify :contains("' + str + '")').html(function () {
        var check = $('.linkify a:contains("'+str+'")');
        if(check.length ==0){           
        return $(this).html().replace(str, "<a href='"+href+"'>" + str + "</a>")
        }
    });
}
replaceToLink("nisi","http://google.se");replaceToLink("nisi","http://google.se");