How To Use Performant Next-Gen Images With CSS Image-Set

Using Performant Next-Gen Images in CSS with image-set

In web development today, optimizing images for performance is a key component of any successful website or application. One way to do this is with a technology known as image-set. Image-set enables developers to specify multiple versions of an image, allowing the browser to use the most appropriate version depending on the context. This can significantly speed up loading times for websites and applications, resulting in a better user experience overall.

What is image-set?

Image-set is a feature that was introduced in CSS Level 4. It allows developers to define a set of images to be used for a particular element. Instead of loading a single image, the browser will select the correct image for the current environment. This could be a higher resolution version for desktop screens, or a low resolution version for mobile devices. The browser will automatically select the appropriate image based on the device’s capabilities.

Why Use Image-Set?

Using image-set can be beneficial in several ways. Firstly, it helps optimize loading times for websites and applications. By selecting the appropriate image for the environment, the browser avoids downloading unnecessary image data. This results in faster loading times, which is especially important for users with slower internet connections. In addition, using image-set can improve accessibility. For visually impaired users, the browser can select an image with higher contrast or larger font size. This improves usability for these users, making your website more inclusive. Finally, image-set can also reduce latency when switching between different devices and operating systems. By specifying multiple versions of an image, the browser can seamlessly transition between them without having to re-download the entire image from the server.

How to Use Image-Set in CSS

Using image-set in CSS is relatively straightforward. The syntax is similar to the @media rule, with the media query as the selector and the different versions of the image as the values. Here’s an example:

@image-set (image-1 1x, image-2 2x) {
    background-image: url(image-1);
} 

@media (min-width: 600px) {
    background-image: url(image-2);
}

In this example, we are specifying two versions of an image – image-1 and image-2. The browser will automatically select the appropriate version based on the device’s capabilities.

Conclusion

Using image-set in CSS is a great way to optimize images for performance and improve overall user experience. By specifying multiple versions of an image, you can ensure that the browser will always select the most appropriate one for the context.