What is srcset?
The srcset is a powerful image attribute in HTML that eases the process of serving multiple variations of the same image based on the capabilities of the user's device. It is an integral part of responsive web design. Srcset is used to specify a list of source files that the browser can choose from based on its own criteria such as the device display size, the density of the device’s screen and the settings of the browser. It ensures that users get served the best-suited image for their browsing situation. For instance, a user browsing on a high-resolution 4K display is served a high-resolution image, while a user on a small screen, such as a mobile device, is served a smaller and less heavy image, ensuring faster load times and a better browsing experience.
Why is srcset important?
Srcset has the ability to present different images based on the user’s device specifications, which can significantly improve a site’s loading speed performance, ensuring visitors have a smooth and engaging experience.
Another important aspect is its significant contribution to SEO. Site speed being one of the ranking factors, and having faster loading images can improve your position on search engines. This feature also significantly improves user engagement metrics such as bounce rate and time spent on site, which can further help in SEO.
Finally, srcset allows you to cater to the variety of screen sizes and resolutions used today. By enabling the delivery of images that are best suited for each device, you improve the device compatibility of your site, increasing its accessibility and user-friendliness.
Types of srcset
Srcset attribute provides two types of hints to the browser. One is a width descriptor (w) which tells the browser the actual width of the image, and the other is a pixel density descriptor (x) which informs about the resolution of the image.
The width descriptor is used when you are dealing with images of different sizes. It allows the browser to pick an appropriately-sized image to display on different screen sizes. Meanwhile, the pixel density descriptor is beneficial when dealing with images on high-resolution (Retina) screens.
Together they offer a lot of control over how your images render across different devices, which ultimately enhances your site’s responsiveness and performance.
Examples of srcset
Srcset using width descriptor
<img srcset=”small.jpg 500w, medium.jpg 1000w, large.jpg 1500w” src=”default.jpg” alt=”example”>
Srcset using pixel density descriptor
<img srcset=”standard.jpg, highres.jpg 2x” src=”default.jpg” alt=”example”>
Handy tips about srcset
To make the most out of the srcset attribute, there are a few best practices to keep in mind:
1. Always provide a fallback image using the src attribute.
2. Use the sizes attribute along with srcset to give the browser more information about how the image will be displayed.
3. Use the right file types. Using vector images for icons and logos can help reduce the complexity of managing multiple image sizes.
Conclusion
Srcset is an extremely valuable attribute for modern-day web design, offering both improved performance and usability. By using it correctly, you can ensure that your website delivers a seamless browsing experience across a variety of devices and screen sizes, contributing positively to your SEO efforts.
Frequently Asked Questions
1. What does srcset do?
Srcset serves different versions of an image based on the user’s browsing environment; this includes factors such as screen size and resolution.
2. How does srcset improve website performance?
Srcset improves site performance by ensuring that smaller, quicker loading images are displayed on smaller screens, which also leads to less data usage.
3. What are the types of descriptors in srcset?
Srcset uses two types of descriptors, width (w) and pixel density (x), to optimize image selection.