CSS Textarea that expands as you type text [duplicate]

Answer 1

This seems to be much more efficient and handles max-height

$(ctrl).on('paste input', function () {
    var dyLineHeight, dyMax, dyHeight;        
    if ($(this).outerHeight() > this.scrollHeight)
        $(this).height($(this).outerHeight() - parseFloat($(this).css("borderBottomWidth")) - parseFloat($(this).css("borderTopWidth")));
    dyLineHeight = Math.max(3, parseInt($(this).css("line-height")));
    dyMax = parseInt($(this).css("max-height"));
    while ($(this).outerHeight() < this.scrollHeight + parseFloat($(this).css("borderTopWidth")) + parseFloat($(this).css("borderBottomWidth")))
        {
        dyHeight = $(this).height();
        if (dyHeight >= dyMax)
            break;
        $(this).height(dyHeight + dyLineHeight)
        }
});