Remove input placeholder using jquery

Should work:

$(':input').removeAttr('placeholder');

Get all the inputs, and attach a change event handler, inside the event handler get the value from all the inputs, join the values together, and if it's still nothing, none of the inputs have a value, if it has length, at least one of the inputs have value, and you can remove the placeholder attributes :

var inputs = $('input[type="text"]');

inputs.on('change', function() {
    if ( $.map(inputs, function(el) { return el.value; }).join('').length ) 
        inputs.removeAttr('placeholder');
});

FIDDLE

I DONT RECCOMEND to remove placeholder

instead, make a focus, and this will automatically hide placeholder at that moment:

$(element).focus();

.removeAttr()

var txtbox = $('input[type="text"]');
txtbox.change(function () {
    txtbox.removeAttr('placeholder');
});