HTML Window length Property

The HTML Window length property returns the number of <iframe> elements in the current HTML document.


Following is the syntax −


Let us see an example of HTML Window length property −


 Live Demo

<!DOCTYPE html>
   body {
      color: #000;
      height: 100vh;
      background-color: #8BC6EC;
      background-image: linear-gradient(135deg, #8BC6EC 0%, #9599E2 100%);
      text-align: center;
   .btn {
      background: #db133a;
      border: none;
      height: 2rem;
      border-radius: 2px;
      width: 40%;
      display: block;
      color: #fff;
      outline: none;
      cursor: pointer;
      margin: 1rem auto;
<h1>HTML Window length Property</h1>
<iframe src=""></iframe>
<button onclick="display()" class="btn">Show the number of iframe</button>
<div class="show"></div>
   function display() {
      document.querySelector('.show').innerHTML = 'Number of iframe is: ' + window.length;


Click on “Show the number of iframe” button to display the number of iframe in the HTML document −