Image Tag Optimization: Lazy Loading vs Eager Loading

In HTML, the loading attribute on an <img> tag is used to specify the loading behavior of the image. The two primary values for this attribute are lazy and eager. Here's the difference between them:

loading="lazy"

• Behavior: The image is loaded only when it is about to enter the viewport, i.e., when the user is likely to see it soon.

• Use Case: This is useful for images that are lower down on the page or not immediately visible when the page loads. It helps improve the initial load time of the page and saves bandwidth for users.

• Performance Impact: Reduces the initial load time and resource usage, leading to a faster page load experience for users. This is especially beneficial for pages with many images or users with slower internet connections.

loading="eager"

• Behavior: The image is loaded immediately, regardless of whether it is in the viewport or not.

• Use Case: This is suitable for images that are immediately visible to the user, such as hero images, above-the-fold content, or any critical visual content that should be displayed as soon as possible.

  1. Hero Image or Banner: The main image at the top of a webpage, often called the hero image or banner, is crucial for the first impression.

  2. Logo: The logo of the website, which is usually at the top left corner and part of the site's branding.

  3. Above-the-Fold Content: Any image that appears in the portion of the webpage visible without scrolling, known as above-the-fold content.

• 

• Performance Impact: Can increase the initial load time since all images with loading="eager" will start loading as soon as the page starts to load. This might be necessary for ensuring critical content is displayed without delay but can lead to slower page loads if overused.

Example Usage:

Lazy Loading:

<img src="example.jpg" alt="Example Image" loading="lazy">

Eager Loading:

<img src="example.jpg" alt="Example Image" loading="eager">