JSFiddle - React, Tailwind, and code Playground

HTML

<div class="test">text for test</div>

CSS

.test span
{
    color: red;
}

JavaScript

var html = $('.test').html();
var ret  = "";
$.each(html.split(''), function(k, v) {
    ret += "<span>" + v + "<span>";
});
$('.test').html(ret);