try this one :

 $('html').keyup(function(e){if(e.keyCode == 8)alert('backspace trapped')})  

Regular javascript can be used to trap the backspace key. You can use the event.keyCode method. The keycode is 8, so the code would look something like this:

if (event.keyCode == 8) {
    // Do stuff...
}

If you want to check for both the [delete] (46) as well as the [backspace] (8) keys, use the following:

if (event.keyCode == 8 || event.keyCode == 46) {
    // Do stuff...
}

Working on the same idea as above , but generalizing a bit . Since the backspace should work fine on the input elements , but should not work if the focus is a paragraph or something , since it is there where the page tends to go back to the previous page in history .

$('html').on('keydown' , function(event) {

        if(! $(event.target).is('input')) {
            console.log(event.which);
           //event.preventDefault();
           if(event.which == 8) {
            //  alert('backspace pressed');
            return false;
         }
        }
});

returning false => both event.preventDefault and event.stopPropagation are in effect .