JSFiddle - React, Tailwind, and code Playground

HTML

Hello World<br />   <br />
	Hello World<br />   <br />
	Hello World<br />   <br />

JavaScript

// it's better to wait for document ready instead of window.onload
    window.onload = function () {
        // get all `br` tags, defined needed variables
        var br = document.getElementsByTagName('br'),
            l = br.length,
            i = 0,
            nextelem, elemname, include;
            
        // loop through tags
        for (i; i < l - 1; i++) {
            // this flag indentify we should hide the next element or not
            include = false;
            
            // getting next element
            nextelem = br[i].nextSibling;
            
            // getting element name
            elemname = nextelem.nodeName.toLowerCase();
            
            // if element name is `br`, set the flag as true
            if (elemname == 'br') {
                include = true;
            }
            
            // if element name is `#text`, we face text node
            else if (elemname == '#text') {
                // if text node is only white space, we must pass it
                // this is because of something like this: `<br />   <br />`
                if (! nextelem.data.replace(/\s+/g, '').length) {
                    nextelem = br[i+1];
                    include = true;
                }
            }
            
            // if the element is flagged as true, hide it
            if (include) {
                nextelem.style.display = 'none';
            }
        }
    };