Gmail sort by sender bookmarklet (drag the code to bookmark bar)

gmail_sort_by_sender.js

javascript:(function() {
    function sortEmailsBySender() {
        var emails = Array.from(document.querySelectorAll('.zA'));
        emails.sort(function(a, b) {
            var senderA = a.querySelector('.yW span').innerText.toLowerCase();
            var senderB = b.querySelector('.yW span').innerText.toLowerCase();
            return senderA.localeCompare(senderB);
        });
        emails.forEach(function(email) {
            email.parentNode.appendChild(email);
        });
    }
    sortEmailsBySender();
})();

Well, it seems to work sometimes now after refreshing browsers and increasing the number of messages per page. Thanks for posting the code.