JSFiddle - React, Tailwind, and code Playground

HTML

<div>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum ipsum velit, placerat eu blandit nec, malesuada eget leo. Vestibulum a odio at odio euismod ultricies. Proin vitae dui id mauris eleifend dignissim eget ac arcu.</div>
<div class="shrink">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum ipsum velit, placerat eu blandit nec, malesuada eget leo. Vestibulum a odio at odio euismod ultricies. Proin vitae dui id mauris eleifend dignissim eget ac arcu.</div>

CSS

div {
    height:150px;
    width:150px;
    border:1px solid black;
    float:left;
}

JavaScript

$(".shrink").each(function(){
    var outer=$(this),fontSize=parseInt(outer.css('font-size'),10),
        wrapper=$("<div style='height:auto;width:auto;border:0;'/>");
    wrapper=outer.wrapInner(wrapper).children(":first");
    while(outer.height()<wrapper.height() && fontSize>0) {
        fontSize-=0.5;
        wrapper.css("font-size",fontSize+"px");
    }
    outer.css("font-size",fontSize+"px");
    wrapper.contents().unwrap();
});