Сохранение любого текста средствами браузера. Вот для примера сохранение полезных кодов:
var title = document.getElementsByClassName('bmenu')[0].innerText;

var code = document.getElementsByClassName('backcode')[0].innerText;

var data = title + '\n\n' + code;

saveFile(title + '.txt', data);

                        
function saveFile(filename, data) {



    var blob = new Blob([data], {type:'text/plain'});



    var saveLink = document.createElement("a");



    saveLink.download = filename;



    saveLink.innerHTML = "Save file";



    if (window.webkitURL != null) {



        saveLink.href = window.webkitURL.createObjectURL(blob);



    } else {



        saveLink.href = window.URL.createObjectURL(blob);



        saveLink.onclick = destroyClickedElement;



        saveLink.style.display = "none";



        document.body.appendChild(saveLink);



    }



    saveLink.click();



}



 



function destroyClickedElement(event) {



    document.body.removeChild(event.target);



}