Why Is Boots Website So Slow? Here Are The Reasons

Boots is a Brish retailer of health and beauty products. They also own a chain of pharmacies in the UK, Ireland, Norway, Italy, and the Netherlands

A speed report from Lighthouse paints a rather grim picture and scores Boots website 14 seconds on the speed index (SI), and 30 on Performance.

There are many reasons why the Boots website is so slow. This includes:

• Bloated JavaScript files
• Unused CSS files
• Unnecessarily large image files
• Old Image formats
• Large DOM size

Let’s look at each of these reasons and identify potential ways that Boots can make their website load faster.

But before we do that, a quick word about our website CWVIQ.com - we are a free email alert service that sends out notification any time your website is loading very slowly (often due to heavy traffic, or poor scripts). If you have a website, consider setting up an alert so that you can fix issues before they become major. 

Bloated JavaScript files

Boots uses a lot of JavaScript to run the website. However, loading them all from one source could slow up the performance of the website. Boots can avoid this by splitting the code into smaller files. This way, you only load files that are necessary.

The Boots website can be as much as 3.45 seconds faster by adopting this technique.

Unused CSS files

Boots uses CSS files to load the styling elements for the website. However, this file contains a lot of unused scripts that can be slowing down page loading by as much as 0.45 seconds. Code splitting may help avoid this issue.

Unnecessarily large image files

Another common problem that users face – especially when they access the website while on the move – is having to load unnecessarily large image files that are not optimized for the mobile phone. Not everyone has access to WiFi at all times. Loading oversized product images is unnecessary.

According to the Lighthouse estimate, Boots website homepage can load 1.48 seconds faster if it made all the images more cellular-data-friendly.

Old Image formats

The Boots website uses a lot of JPG and PNG files that are considered outdated and heavy for modern web use. Replacing them with WebP and AVIF files can save as much as 1.83 seconds from the page loading time.

Large DOM size

The Boots website takes close to 22 seconds to evaluate all the scripts, parse them, compile, and render them. This can be minimized by minimizing the main-thread work.

They may also look at reducing the number of nodes in the DOM. In simpler terms, you need to make sure that the main HTML code is smaller and has fewer nodes. I have explained this in greater detail in this article about DOMContentLoaded.

Ineffective Caching Policy

A website like Boots is made of several components, including a lot of images, and other media files. Caching, or storing these components in your local computer, enables your browser to load the website much faster when you come back a second or third time.

With Boots, however, the cache for most media files clear is deleted every 20 minutes. This means that the website is loaded completely from scratch any time you visit after 20 minutes. Enabling a longer cache period could make loading pages faster and more user-friendly.