JSFiddle - React, Tailwind, and code Playground

JavaScript

var s = "<!DOCTYPE html>\r\n \
<html> \
  <head> \
    <title>Data already exists</title> \
  </head> \
    </html>";
        
var dummy = document.createElement("div");
dummy.innerHTML = s;
var title = dummy.getElementsByTagName("title")[0].innerText;
console.log(title);

var titleRegex = s.match(/<title>([^<]+)<\/title>/)[1];
console.log(titleRegex);