Resizing an iframe based on content is a common task in web development, and can be achieved using JavaScript. The idea is to dynamically adjust the height of the iframe to match the height of its content, so that the entire content is visible without any scrolling.

Here’s a step-by-step guide to resizing an iframe based on content using JavaScript:

1. Get a reference to the iframe element. You can use the document.getElementById() method to get a reference to the iframe element, using its ID.

2. Add an event listener to the iframe element that will trigger the resize function whenever the content changes. You can use the window.addEventListener() method to listen for the “message” event, which is fired when the content of the iframe sends a message to the parent window.

3. Create a function that will resize the iframe based on its content. Inside the function, get the height of the iframe content using the scrollHeight property, and set the height of the iframe element to match.

Here’s an example code snippet that demonstrates how to resize an iframe based on content:

<iframe id="my-iframe" src="https://example.com"></iframe>

<script>
  const iframe = document.getElementById('my-iframe');

  function resizeIframe() {
    iframe.style.height = iframe.contentWindow.document.body.scrollHeight + 'px';
  }

  window.addEventListener('message', resizeIframe);
</script>

In this example, the resizeIframe() function gets the height of the iframe content using the scrollHeight property of the iframe’s contentWindow.document.body object. It then sets the height of the iframe element to match, using the style.height property.

The window.addEventListener() method listens for the “message” event, which is fired when the content of the iframe sends a message to the parent window. This event is used to trigger the resizeIframe() function whenever the content changes.

Overall, resizing an iframe based on content involves getting a reference to the iframe element, adding an event listener to the iframe, and creating a function that will resize the iframe based on its content. With the right configuration, you can ensure that your iframes display their content properly and without any scrolling.