How does image optimisation affect website speed?

How Does Image Size Affect Website Speed?

When a user visitors your website, their browser will requires and download the necessary resources needed to display your web page. This includes HTML files, JavaScript files, images, and CSS style sheets. Images tend to take up the largest portion of the data:

• File size and bandwidth – Large image files take up more bandwidth, meaning they take longer to download. This delay will impact the loading time of your web page. If users have a slower internet connection, or if they are using a mobile device, this can result in a significant waiting time for the page to load, which negatively impacts user experience (UX)
• Rendering – Large images do require more time for the browser to render once they are downloaded. This process negatively impacts the appears of your other page elements, which slows down the perceived loading time
• Load on server – Larger images increase the load of your web server, in turn slowing down your website, especially when the server is handling a number of requests at the same time. This is often seen in high-traffic websites
• Issues relating to caching – Larger files are less likely to be cached by browsers, meaning users need to download the same large files over numerous sessions, negatively impacting the user experience (UX)

Understanding Lossless and Lossy Compression

There are two types of image compression for websites, lossy and lossless:

Lossy Compression

When it comes to lossy compression, there is some image data that is lost during the process. This method reduces the bytes of the image, by reducing the colours, converting it into a smaller indexed colour image.

The benefit to lossy compression is the reduction in size. With this type of compression, the image cannot be restored to it's original form. It is very effective when it comes to saving on storage space and reducing file size.

Lossless Compression

With this compression process, there is no data lost from the image, but it is rearranged. Bytes are encoded to an efficient coding, preserving the quality, while reducing the size of the file. The benefit is that you can restore the image to its original form.

Why You Should Compress Your Website Images

Image compression is essential to the speed and efficiency of your website. The amount of data stored on the website will affect the speed. When you compress images for your website, you reduce the file size, taking up less space, thereby increasing loading times, and improving user experience (UX).

Conclusion

Image optimisation is essential in improving your website speed. This process makes the image file smaller, speeding up loading times and improving your users experience. These images require less bandwidth, reducing strain on the server, while allowing your pages to render quickly, enhancing user satisfaction and boosting your SEO rankings.