How to Defer Video Loading for Increase Page Speed?

Video emblem and stopwatch next to it

Latest update: July 23, 2024

Users expect quick access to information, making every second (or fraction thereof) crucial to the success of a website. This importance is further magnified when considering the integration of multimedia elements like videos, which are known to significantly impact loading times. This guide delves into the effective strategy of deferring video loading, a practice that holds the potential to marry the need for rich content with the demand for speed, ensuring a website remains both engaging and efficient.

Deferring Videos

Deferring the loading of video files until after the initial page load can remarkably accelerate page speed. This technique mirrors methods used to defer images, focusing on postponing resource-heavy operations until they’re needed.

How Embedded Videos Work?

Embedding a video involves loading an iframe, which during page load, may call for numerous additional resources, significantly impacting load time. These resources range from JavaScript files to provider analytics, all contributing to slower page speeds.

To further refine the strategy of deferring video loading and to stay updated on the latest best practices for web performance optimization, visiting web.dev site is highly recommended.

How to Defer Videos?

To defer videos, a slight modification to the video’s embed code is required, alongside a simple JavaScript function. The process involves removing the video URL from the src attribute and placing it in a data-src attribute, with the JavaScript handling the deferred loading post-page load.

The HTML

<iframe width="560" height="315" src="" data-src="//www.youtube.com/embed/OMOVFvcNfvE" frameborder="0" allowfullscreen></iframe>

The JavaScript

<script>function init() {    var vidDefer = document.getElementsByTagName('iframe');    for (var i=0; i<vidDefer.length; i++) {        if(vidDefer[i].getAttribute('data-src')) {            vidDefer[i].setAttribute('src',vidDefer[i].getAttribute('data-src'));        }     }}window.onload = init;</script>

Usage

  1. Get the embed code of the video you wish to use;
  2. Modify the embed code as described;
  3. Place the script near the closing body tag in your HTML.

By implementing these steps, you can maintain the interactive and engaging nature of having videos on your site without compromising on page load speeds, ensuring a swift and smooth user experience.

Benefits of Deferring Video Loading

  • Improved Initial Load Time: Significantly reduces the time it takes for the initial content to become visible to users;
  • Enhanced User Experience: Prevents users from getting frustrated with slow page loads, potentially increasing engagement and reducing bounce rates;
  • Optimized Resource Utilization: Delays the loading of heavy resources until they are actually needed, improving overall page performance.

Video Loading Strategies

StrategyInitial Load TimeUser ExperienceSEO Impact
Immediate Video LoadingSlower due to resource-heavy video filesPotentially frustrating with visible delaysNegative, as search engines penalize slow-loading pages
Deferred Video LoadingFaster, as video loads after essential contentSmooth and unobstructed access to initial contentPositive, enhanced page speed can improve rankings

This table underscores the stark contrasts between immediate and deferred video loading, highlighting the advantages of the latter in terms of performance and user satisfaction.

Key Points of Implementing Deferred Video Loading

  1. Modify the Embed Code: Remove the video URL from the src attribute and relocate it to a data-src attribute;
  2. Leverage JavaScript: Utilize a simple JavaScript function to load the video content after the page has initially loaded;
  3. Test and Optimize: Regularly test your page’s load time with and without deferred loading to quantify the improvement and make necessary adjustments.

By embracing these principles, web developers can ensure their websites remain dynamic and multimedia-rich without compromising on the speed that users have come to expect.

Conclusion

The balancing act between incorporating rich media content and maintaining swift page load times is a challenge that modern web developers face. The technique of deferring video loading emerges as an invaluable strategy in this context, offering a means to enhance user experience and improve SEO rankings simultaneously.

By understanding and implementing this approach, developers can significantly boost their website’s performance, ensuring that it serves as a swift, efficient gateway to the engaging content users seek. This optimization not only meets the immediate needs of users but also aligns with the broader goals of web development, marking a step forward in the evolution of the internet as a fast, accessible, and richly interactive medium.