I think you have a typo here <div id="paste"> //missing one double quote

There is multiple problems with your code, it should be :

$("#paste").append('<div class="form-control">' + $(this).val() + '</div>')

• It should be $("#input-text").val() not $("#input-text").value Also you can change $("#input-text").val() to $(this).val()
• You need to wrap your html <div class="form-control">$("#input-text").value</div>}) also you have a } that should not be there.

Demo

$("#input-text").keyup(function() {
  $("#paste").append('<div class="form-control">' + $("#input-text").val() + '</div>')
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="input-text" class="form-control" placeholder="Input Text">
<div id="paste"></div> //code to be pasted here

All the typo-issues aside, your issue is that you are using .append with a complete html string.

This will append html.

If you want what you input (eg html tags) to appear as text, then you need to use .text(newtext). As you're wrapping the input in a div, the easiest way is to generate the div, then add the text. You could also encode the text when you add it as html, but using .text(txt) does this for you.

var div = $('<div class="form-control">');
div.text($(this).val())
$("#paste").append(div);

You can make this a single line by using .appendTo(), which returns the new element rather than .append() which returns the outer element, then chain .text().

$("#input-text").keyup(function() {
  $('<div class="form-control">').appendTo("#paste").text( $(this).val() );
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="input-text" class="form-control" placeholder="Input Text">
<div id="paste"></div> //code to be pasted here