5 Site Speed Case Studies

E-commerce giant Amazon conducted a simple calculation on how a drop in site loading speed by one second can impact revenue. Shockingly, the company discovered it could lose $1.6 billion annually if its page load speed drops by a second. 

Google did a similar test and discovered page load slowdown by four-tenths of a second could result in a loss of 8 million daily searches. 

What does this imply for Google? It means fewer ads and a reduction in revenue.  

So, site speed is something every online business and blog must take seriously. Here is how a it can impact a business or blog. 

  • Website delay of one second can cause a 16% reduction in customer satisfaction. 
  • As many as 46% of users dislike revisiting poor-performing websites. 
  • Website delay of a second can cause over 7% loss in conversion. 

So, if you have an online business or a blog, make sure your website loads faster. We’ll be sharing various site speed case studies, so you can see what many businesses and marketers did to turn things around. 

In addition, we’ll share tools and tips to boost conversion rate. Read on! 

Must-Know Website Speed Case Studies

These case studies highlight the impact of site speed on conversion rate and performance.

Case Study 1: Portent Discovered That Fast Loading Websites Enjoy Higher Conversion Rates:

This internal research by Portent, an integrated marketing services company, demonstrates how website speed can impact conversion rate. 

In this study, Portent considered 100 million page views from approximately 20 websites (B2B and B2C). They were looking for as much conversion data as possible. 

The websites (B2B and B2C) that Portent considered were national travel brands, including small firms in the software niche. 

The Result: 

Note that this study was conducted for B2B and B2C websites.

Portent’s discovery for B2B with varied site loading speed was an eye-opener. They discovered that blazingly fast websites’ conversion rate was 3X higher than modestly fast ones and 5X higher than slower websites. 

In other words, the conversion rate of a website that loads in a second is 3X higher than a site that loads in 5 seconds. In the same vein, the conversion rate of a site that loads in 1 second is 5X higher than another that loads in 10 seconds. 

Now, here is what Portent discovered when they examined B2C websites. 

When Portent analyzed B2C websites, they discovered that websites that load in 1-second boast an e-Commerce conversion rate 2.5X higher than the ones that load in 5 seconds. 

The Key Takeaway: 

Website loading speed affects conversion massively. Don’t forget that many visitors that land on your site have tasted other fast-loading ones before arriving. So, if your site offers them something different (doesn’t load fast), your potential visitors could move elsewhere. 

Portent’s conclusion was that a website loading speed of 1-4 seconds is ideal for businesses seeking to boost goal conversion rates. 

The goal conversion rate involves visitors completing simple tasks like providing contact information, emails, etc. 

However, e-Commerce platforms seeking to boost transaction conversion rates should aim for a website load speed of 1 – 2 seconds

Now, this is simple logic. Many visitors might quickly get frustrated and abandon their carts if a website takes a longer time to load. 

So, test your website’s loading speed to ensure you are on course. And remember, a website that loads faster will likely have a higher conversion rate. 

Case Study 2: Pfizer Reduced Bounce Rate By 20% By Improving Website Loading Speed by 38%:

This case study was conducted by Pfizer, though they partnered with Google. The aim was to reduce website loading speed, offering an improved mobile experience.

Pfizer, like other brands, understood the importance of owning a site that loads faster on mobile devices and desktop computers. 

In this specific case study, Pfizer examined their mobile effort and discovered that many of their websites were massively slow on mobile and almost entirely inaccessible. 

The company has approximately 40 promoted brands, with about 15 of the brands in operation having complete websites. And what’s more interesting is that these websites have a lot of functionality. 

Pfizer’s analysis made them realize that all their websites take longer time to load on mobile devices. One of their websites took approximately 21 seconds to load. 

The load speed made the company realize it had been losing customers all along. The solution was to fix the slow websites to improve user experience. 

What the company did was simple and had a lasting impact to date. They gathered all the senior executives and marketers in one room to discuss the situation. Then and there, they partnered with Google. 

One thing Pfizer did that changed the whole game was that the whole team agreed on a “Speed budget.”

The speed budget was the amount of time Pfizer wanted all its websites to load. 

The Result: 

Pfizer’s resilience and Google’s expertise were vital in addressing the problem. Pfizer identified the problem, wanted a lasting solution, and got one. 

To this day, it takes approximately 3 to 5 seconds for Pfizer’s websites to load fully. And given the number of images and functionalities on these sites, you would agree that 3 to 5 seconds is a decent load time to have. 

Pfizer’s “speed budget” has become part and parcel of the company. Everyone in the company understands and works in line with this speed budget in mind. 

In other words, any functionality added or images uploaded on the websites mustn’t blow the speed budget. 

Key Takeaway:

The adjustments Pfizer made increased their website load speed by 38%. Bounce rate improved by 20%.

What can other businesses learn from this? It is essential to have a “Speed budget.”How fast do you want your website(s) to load? Your speed budget should entail this. 

You’ll also discover that Pfizer didn’t just create a “speed budget” and folded its arms. They made it a duty for everyone in the company to adhere to the load speed. 

Another takeaway is that testing is vital. Test your website’s load speed from time to time. This way, you’ll know if the load speed has dropped and make the necessary adjustment on time. 

If Pfizer had not tested their websites, they wouldn’t have known it took 21 seconds for some of their sites to load.

Case Study 3: A Google Analysis Showing That A Site’s Loading Speed Can Increase Bounce Rate By 123%:

Though Google conducted this analysis in 2017 and updated it in 2018, it is still relevant to this day. 

This analysis is an eye opener for marketers looking to reap maximum benefit from their mobile effort. From the analysis, Google discovered that it took mobile landing pages 15 seconds to load. 

When you consider the fact that website speed equals revenue, you’ll understand why website owners need to do everything possible to make their website load faster. 

Another thing Google discovered from this analysis was that despite more than half of traffic coming from mobile, the conversion rate on a desktop was still way higher. 

How did Google conduct this analysis, and what was the motive?

Firstly, note that Google conducted this analysis to have a better understanding of how their advertising partners were faring. 

To achieve a result that reflects on the internet community, Google used a large sample size. They examined 11 million mobile ad landing pages across 213 countries. 

The Result:

The result from the analysis wasn’t a pleasant one. But then, it’s still worth sharing and reading. Google discovered that despite the increased traffic, thanks to the 4G network, tons of mobile sites still took longer to load. 

However, one of the things responsible for the slow loading speed was the fact that these mobile websites appeared bloated with too many elements.

A Handy Tip: Google covered a wide range of sectors in this research, as they wanted to make the result a reflection of mobile’s performance across the web. The sectors ranged from finance to travel. 

Now, let’s go back to the analysis. 

In all the sectors Google reviewed, it discovered that automotive, technology and retail take longer to load. When they analyzed further, they discovered these sectors boast some of the most bloated pages.

How did Google determine the 123% increase in bounce rate with respect to website loading speed?

Google displayed its technological advancement by using a trained deep neural network. The neural net was modeled according to the human nervous and brain. 

The neural net was a game-changer as Google loaded it with tons of conversion and bounce rate data. Results from the neural net were also 90% accurate. 

What did Google discover with the neural net?

As website loading speed increases from 1 to 10 seconds, the probability of a visitor bouncing from the said mobile website increases by 123%. 

The analysis also showed that the conversion rate dropped by 95% when the page’s images, texts, and titles went from 400 to 6000.

The Key Takeaway:

You can have a fancy or professional-looking website with diverse functionalities and elements that may impress visitors. But if your mobile website doesn’t load faster enough, the bounce rate will likely increase, and the conversion rate could drop. 

The ideal time for a mobile page to load is 3 seconds, though the faster, the better. Many visitors may not have the patience to wait 10 or 21 seconds for a mobile page to load. They would rather spend that few seconds visiting one or more of your competitors.

So, in all you do, ensure your website’s mobile page’s load speed is faster. 

Case Study 4: Vodafone Recorded 8% Increase In Sales After Optimizing Core Web Vitals:

Vodafone is a leader in the telecommunications sector. They have mobile and fixed networks and operate in Europe and several African countries. 

Vodafone ran the A/B test on a landing page in this case study. In the test, “A” was the version optimized for web vitals and had a 31% better LCP score than version B. 

Vodafone’s traffic was from different paid media, such as social media, search, etc. And while they sent 50% of the paid traffic to landing page A (the optimized landing page), landing page B (baseline) had 50%.

Ultimately, both landing pages recorded 100K clicks and 34K visitors daily. And the only difference between both landing pages was that Vodafone optimized page A for web vitals, while page B wasn’t optimized.

The Result:

The result Vodafone got from this A/B test was quite interesting. It recorded an 8% increase in sales, an indication that optimizing for web vitals can boost sales. 

In addition, the test result showed a 15% increase in the lead-to-visit rate (percentage of users that later became leads versus the total number of visitors).

Cart to visit rate (the number of users that checked out their carts versus the total number of visitors) also jumped by 11%. 

The Key Take Away:

Having a fast LCP is very crucial. It shows your targeted audience or visitors that your website has great value and is useful.

This Vodafone test also demonstrated the need to optimize web vitals on a website.

The meaning of some terms used in the Vodafone case study

  • LCP (Largest Contentful Paint) – This measures the time it takes (in seconds) from when the specific page starts loading to the point where the largest image element or text block gets rendered on the screen. LCP is one of the core web vitals.
  • Core Web Vitals – This refers to a group of metrics such as responsiveness, speed, and visual stability, which can help website owners to measure and determine user experience on the web. 

Case Study 5: Propellernet faster visits can lead to a 19% higher conversion rate:

Prepellernet, like many digital marketers and online businesses, is familiar with Google’s report on website speed and how it impacts conversion rate. However, Propellernet wanted to be sure of this and decided to conduct an experiment.

Propellernet’s theory reflects the messages Google and other studies has been spreading that faster visits would have better conversion.

How did Propellernet conduct this experiment? 

They used a RUM (Real User Monitoring) tool to help precisely track the landing page speed metrics of the website used. They also tracked when conversions took place on the website, including the order values. 

The Result: 

Propellernet observed massive differences between mobile and desktop devices. They discovered that the conversion rate on desktops was higher than on mobile devices.

The conversion rate on desktop visits that were faster was 19% higher than slower desktop visits. 

Another interesting fact was the results from Android and iOS devices. Propellernet reported that iOS devices had a better conversion rate than Android devices. 

However, many factors were responsible for the high conversion rate iOS devices had over Android. Price is one of them. The thing is iOS devices are more expensive than Androids. So, a user that can pay a hefty fee on an iOS device will not be so price-sensitive. 

Furthermore, iOS devices boast a lot of sophisticated features and may likely load pages faster than Android devices. Remember, faster page loading can result in an increased conversion rate. 

The Key Take Away

Testing and knowing a website’s load speed is easier said than done. A visitor’s internet speed can determine how fast a page will load.  

Nevertheless, testing website load speed is necessary to boost the conversion rate. Through testing, you can determine if your website is slow and make the necessary adjustment. 

Case Study 6: TUI implemented new processes and technology and reduced loading time by 78%

TUI, a transport operator, based in the Nordics, was interested in making its business more customer-centric. They knew adjusting prices wouldn’t make much difference if customers were leaving their websites in droves, thanks to slow load speed.     

The organization had to create a speed project to tackle the problem. And excitingly, they knew that for the project to be successful, everyone in the company had to be on the same page. 

How did TUI achieve its aim?

The easiest way to solve a problem is recognizing the scale of the problem and taking action. Since the organization had identified the problem as site speed, it became a top priority for everyone involved. 

In other words, the designers at TUI started paying attention to site speed in their designs. Site speed was discussed at every meeting too. 

The management understood that their speed project wouldn’t succeed unless everyone was on board. With everyone on the same page, it was easier to implement diverse development techniques that improve site speed. 

The Result:

The techniques and technology TUI implemented paid off. The organization recorded a 31% reduction in bounce rate and a 78% decrease in load times.

The Key Take Away:

Site speed is an essential factor no business owner or marketer should neglect. Why? Besides being a ranking factor, various studies have shown that there’s a correlation between conversion rate and site speed. 

In other words, a website that loads faster will have a higher conversion rate than a slow one. 

Must-Have Tools To Boost Conversion Rate 

The CRO (Conversion rate optimization) tools are vital for your marketing campaigns. With these tools, you can collect data about your visitors and websites. The CRO tool lets you understand how people use your website, conduct tests, and identify critical adjustments you need to make to boost the conversion rate. 

Here are the recommended CRO tools you should have in your arsenal as a marketer or website owner. 

1: HubSpot

2: Hotjar

3: Crazy Egg

4: Google Optimize

5: Google Pagespeed

6: Google Analytics

7: Optimizely

Now, let’s discuss each of them in detail.



HubSpot is one of the top tools for conversion rate optimization. Though it is a paid tool, there’s a free trial available for those interested in taking a closer look at what the tool can do. 

With HubSpot, you can gain valuable insight about projects, including contacts already in your database. The dashboard is a breeze to navigate and provides detailed information too. 

From the dashboard, you can see the marketing efforts converting and those that need optimization.

A Handy Tip: One advantage HubSpot has is that it provides valuable information about partners, leads, and clients – all in one place. The HubSpot CRM allows you to create email templates, tags, and schedule calls. 



Hotjar, as the name implies, is another hot CRO tool that provides you with detailed information to make the ideal optimization moves on your website. 

Besides screen recording, Hotjar lets you see the heat map of how visitors navigate your site. 

Hotjar is a paid tool, though it offers a free trial. The only challenge with the free trial is that it is limited. 

A Handy Tip:  In addition to behaviors, Hotjar reveals the voice of your users. It combines feedback and analysis tools to help create a bigger picture of how you can improve your website’s performance, user experience, and conversion rate. 



This powerful CRO tool takes website tracking to another level. You’ll see the heat map of visitors navigating your site, and you can track their clicks. 

Crazy Egg gives you a clear picture of your visitors’ behaviors. And what’s more, you’ll have the privilege of conducting A/B testing to identify the optimization effort that produces the best result.

Crazy Egg offers a 30-day free trial to new users, after which users will have to subscribe to continue gaining access. 

A Handy Tip: Crazy Egg is a breeze to install and is simple. It will comprehensively track your visitors using a heat map, overlay, scroll map, and confetti. 



Google Optimize is a wise choice for marketers seeking a free CRO tool to cut costs and achieve key optimization goals. This tool is from Google itself, and it’s completely free.

With Google Optimize, you can conduct various tests such as split tests, A/B tests, and multivariate tests to determine page performance. 

Google Optimize also integrates with Google Analytics, another important CRO tool that tons of marketers depend on for insight regarding website performance. 

A Handy Tip: The fact that Google Optimize integrates with Google Analytics makes it possible to review reports in one place and take immediate action based on the data. 

In addition to the free access, Google Optimize is also simple to use.



Page speed is a crucial metric every website owner should pay attention to. Not every visitor would have the patience to wait for a slow website to load. Many would rather spend their time checking out other websites than wait. 

Besides being a ranking factor, page speed impacts conversion rate. But thanks to Google, marketers and online business owners can address issues relating to site speed without breaking a sweat. 

The Google Pagespeed gives you insight into your website’s loading time. If the website is slow, you’ll see it and get suggestions on how to improve it. 

A Handy Tip: The Google Pagespeed is a free tool. It is also easy to understand and use— it reports the page’s performance (speed) on desktop and mobile. 

6: Google Analytics:

Google Analytics

Google Analytics is another powerful free tool from the search engine giant Google. Remember, this tool integrates with Google Optimize, another incredible CRO tool.

With Google Analytics, you can figure out the keywords people are searching. This tool also gives you access to valuable data for conversion rate optimization, such as the visitors’ demographics, the devices used, backlink sources, bounce rate, etc.

A Handy Tip: Google Analytics helps you understand user behavior in a way you haven’t. It helps you understand how users interact with your business to improve user experience and drive results.

7: Optimizely:


Optimizely is a highly sophisticated AI-powered CRO tool that helps developers to create and run tests on websites. This tool can help you conduct valuable tests across all the devices and let you know which of the control groups has more significance. 

However, Optimizely is quite expensive. It is one of the most expensive CRO tools on this list, though it’s worth every penny. 

A Handy Tip: Optimizely is a popular experimentation platform that offers experience optimization and lets you run A/B and multivariate tests. 

5 Must-know Tips To Boost Conversion Rate 

Before we go deeper, let’s define conversion and conversion rates. 

Conversion: The term “conversion” refers to the process by which leads change their statuses. For instance, a lead may become a visitor, user or subscriber, free user, then paid customer, and finally, upgraded. 

Conversion Rate: In plain terms, conversion rate refers to the number of people visiting a site to those taking action (converting). 

A high conversion rate is the dream of every marketer or online business owner. But you can’t achieve such a feat by folding your arms.  

There are several factors to consider that can help you boost your website’s conversion rate. 

Let’s take a look of 5 of these crucial factors

1: Headline

2: Page Load Speed

3: CTA’s

4: Navigation

5:  Mobile Friendliness 

1: Use Killer Headlines:

What is the first thing that people see that tells them whether to click or go away? It’s the “Headline.”

If you have well-crafted content, but a weak headline, the number of visitors that’ll land on your page could decrease significantly. 

The headline is you compressing your sales pitch into a short sentence. So, make it captivating. Your headline should make visitors curious, answer the question, be instructional or solve a problem.

2: Page Load Speed:

We shared a couple of case studies here, demonstrating how page load speed can impact conversion. 

We are in a fast-paced world. So, people are hardly patient these days. So, internet users prefer a website that loads faster to one that’s slow. They won’t even mind if the website can load in a blink of an eye. 

If you want to boost conversion rate, make your website faster. Use any of the CRO tools you can get to analyze your website and determine its performance. 

At the start of this post, we gave an example of how much Amazon discovered that it could lose in a year if a page load speed is delayed by one second daily. 

So, make your website as fast as possible, both on mobile and desktop. A 3-second load time isn’t a bad idea.

3: Deploy Powerful CTA’s:

Your CTA (call to action) is essential and can help you boost your conversion rate. It is used to instruct your visitors to perform a specific action. 

In addition to using powerful CTA’s, remember to place them strategically. According to Google, CTA’s are more effective when placed above the fold. 

So, above the fold is the best place for your CTA. This position is the most viewable. 

4:  Make Navigation A Breeze:

Make your website a breeze to navigate on mobile devices and desktops. Make it easy for visitors to move from your landing page to other areas of your website. 

The truth is most online business owners may not consider navigation as a significant factor in boosting conversion rate, but it is. 

When you make it easier for visitors to move around your website, the chances of them converting will increase. 

5:  Make your website mobile-friendly:

This report shows that half of the world’s traffic comes from mobile devices. So while designing your website, consider making it mobile-friendly to benefit from the massive traffic from mobile. 

Besides being a ranking factor, you can boost conversion rate by making your website mobile-friendly. 

Final Thought

These site speed case studies should enable you to gain necessary experience to make the right changes to boost your website speed. You have seen the massive impact an increase in website speed can have on lead generation and conversion. 

People are no longer patient these days. Many are not patient enough to wait for a website to load in over 5 seconds.  

Instead of waiting, most people prefer to visit other websites to get similar information or products.  

So, improve your website speed if you want to boost lead generation, conversion rate, traffic and ranking. 

Md Julhas Alam

Julhas Alam, an SEO expert started his amazing journey in 2014, offering SEO services to businesses across the globe, remotely. He was the go-to SEO professional for many businesses owing to his experience, dedication, trustworthiness, and readiness to bend over to get targeted results.

As the request from clients started increasing, Julhas Alam saw the need to create a team capable of adhering to the high standards built over the years. Thus, he was able to build a remote team in 2016.

Impressively, BitChip Digital Started its physical company in 2020, hiring and developing digital marketing experts, capable of delivering the best digital marketing services.

Today, the company has successfully put together a team of professionals capable of taking businesses to the next level.


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