Implementing lazy loading for images

Lazy loading is a powerful technique for improving the loading time of your website by loading images only when they come into view. This means visitors can access your website faster without having to wait for images to load that are not yet visible.

For a website like Ralfvanveen.com, where speed and user experience are crucial, lazy loading is a must. I explain how to implement lazy loading and what to look out for to maximize the SEO impact.

What is lazy loading and why is it important?

Normally, a browser loads all images on a page regardless of whether the user sees them directly. This often slows loading time considerably, especially for pages with a lot of visual content. Lazy loading avoids this by loading only images that are currently visible in the user’s screen (the viewport).

Lazy loading offers distinct advantages for a Web site such as Ralfvanveen.com. By loading only the required content, the user experience improves significantly due to shorter loading times. This also results in lower bandwidth consumption, which is particularly beneficial for mobile visitors. In addition, faster load times contribute to better Core Web Vitals, which positively affects your SEO performance and rankings.

How does the technique behind lazy loading work?

Lazy loading uses JavaScript or built-in browser features. In modern browsers, lazy loading is a simple and effective way to delay images until they come into view.

An example of code you can copy:

Description of image

Roadmap: Implementing Lazy loading on your website

Here’s how to add lazy loading to your website, with specific attention to SEO and performance:

  1. Check the current state of your Web site
    Use tools such as Google PageSpeed Insights or Lighthouse to see how your Web site is performing. For example, for Ralfvanveen.com, you could look at load times and the number of invisible images loaded at load time.
  2. Use built-in browser functionality
    If your site supports modern browsers, the loading “lazy” property is the fastest and easiest way to implement lazy loading. Add this property to all <img> tags on your site.
  3. Use a JavaScript library
    For older browsers or more complex implementations, you can use JavaScript libraries such as LazyLoad. This library provides advanced options, such as support for background images and dynamic content.
    Example of a LazyLoad script:

var lazyLoadInstance = new LazyLoad({elements_selector: “.lazy”});

And an example of an image in HTML:

<img class=”lazy” data-src=”image.jpg” alt=”Description of image”>

  1. Optimize images in advance
    Make sure your images are optimized before implementing lazy loading. Use tools such as TinyPNG or ImageOptim to reduce the file size without losing quality.
  2. Test your implementation thoroughly
    Check that images load correctly in different browsers and devices. Pay particular attention to mobile performance, as lazy loading often has the biggest impact there.
  3. Monitor and improve: After implementation, you can use tools like Google Analytics to see how lazy loading affects the performance of your website. For example, for Ralfvanveen.com, you can see if the bounce rate has decreased because of the faster load times.

Best practices for SEO in lazy loading

Lazy loading can offer many benefits, but incorrect implementation can negatively impact your SEO performance. Therefore, make sure each image has a descriptive alt text, which supports both accessibility and your search engine optimization.

In addition, make sure your images are crawled and indexed correctly by Google and avoid using JavaScript that hides this content. Also, choose not to lazy-load important images, such as your logo or visually prominent images above the fold, to ensure instant visibility.

Lazy loading is a simple and effective way to improve the performance of your website, especially if you have a lot of visual content like Ralfvanveen.com. By implementing it correctly and taking SEO guidelines into account, you not only provide your users with a better experience, but also boost your search engine rankings.

Senior SEO-specialist

Ralf van Veen

Senior SEO-specialist
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I have been working for 12 years as an independent SEO specialist for companies (in the Netherlands and abroad) that want to rank higher in Google in a sustainable manner. During this period I have consulted A-brands, set up large-scale international SEO campaigns and coached global development teams in the field of search engine optimization.

With this broad experience within SEO, I have developed the SEO course and helped hundreds of companies with improved findability in Google in a sustainable and transparent way. For this you can consult my portfolio, references and collaborations.

This article was originally published on 21 January 2025. The last update of this article was on 22 January 2025. The content of this page was written and approved by Ralf van Veen. Learn more about the creation of my articles in my editorial guidelines.