Run results for: JQuery 1 vs 2 vs 3 vs 4

Test name	Executions per second
✓ jq3.4.1	13,648 Ops/sec
jq2.2.4	13,408 Ops/sec
jq3.7.1	13,358 Ops/sec
jq4.0.0-beta	13,123 Ops/sec
jq1.12.4	10,529 Ops/sec

HTML Preparation code:

<script src='https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js'></script>
<script>
  var $jq1124 = $.noConflict(true);
</script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<script>
  var $jq224 = $.noConflict(true);
</script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script>
  var $jq341 = $.noConflict(true);
</script>
<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
<script>
  var $jq371 = $.noConflict(true);
</script>
<script src="https://code.jquery.com/jquery-4.0.0-beta.min.js"></script>
<script>
  var $jq400beta = $.noConflict(true);
</script>
<div>
  <ul id="menu">
    <li class="menu-item">1</li>
    <li class="menu-item">2</li>
    <li class="menu-item">3</li>
    <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li>      <li class="menu-item">4</li> 
  </ul>
</div>

Script Preparation code:

function tests($) {
    $(".menu-item").eq(2).closest("ul").css({
      "background-color": "red"
    }).parent().css({
      "border": "1px solid blue"
    }).append($("<p></p>").text("Text.").css({
      "background-color": "green"
    })).end().end().remove();
  console.log('tests' + $);
}

Run results for: JQuery 1 vs 2 vs 3 vs 4

Comparing performance of: jq1.12.4 vs jq2.2.4 vs jq3.4.1 vs jq3.7.1 vs jq4.0.0-beta

jq1.12.4

jq2.2.4

jq3.4.1

jq3.7.1

jq4.0.0-beta