How Can I Preload Images in JavaScript to Improve Website Performance?

How to Preload Images Using JavaScript

The function provided for preloading images, preloadImage, is sufficient for the majority of browsers commonly used today. It utilizes the Image object to asynchronously load the specified image, without actually displaying it. Here's how it works:

function preloadImage(url) {
  var img = new Image();
  img.src = url;
}

By assigning the image URL to the src property of the Image object, the browser is instructed to initiate an asynchronous request to fetch the image. The browser will continue to process other scripts while the image is loading. Once the image has been successfully loaded, it can be accessed through the img object for rendering or other operations.

It's important to note that the preloading process is asynchronous and non-blocking. This means that the execution of other scripts will not be blocked while the images are loading. As such, it is advisable to asynchronously loop over an array of image URLs and call preloadImage for each URL to effectively preload multiple images simultaneously.

This technique is widely supported across browsers, including Chrome, Firefox, Safari, Opera, and Microsoft Edge. It is a reliable method for preloading images and improving the performance of web applications by reducing the perceived load time of images that are likely to be used.

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