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eCommerce Website Performance: A Look Into the Industry


The top eCommerce sites in the world are 22% slower than they were last year.

That’s bad.

A customer’s ideal page load time is less than 3 seconds, and today’s top eCommerce sites take 7.25 seconds. That is almost 2 full seconds slower than the average eCommerce site took to load in 2009 (Joshua Bixby).

Why So Slow?

Reason #1: Websites are becoming more complex.

They are heavier and more interactive, as they attempt to support third-party integration (“Share this on Facebook”) and add powerful visuals (well hello, 2MB worth of images). You might assume, naturally, that as technology improves the performance of your website will automatically follow suit. But what this new technology allows you to do online doesn’t change the composition of your website. New technology generally adds to existing site features, rather than replacing them; It’s still made up of the same asset types that need to be thoroughly thought out.

At the same time, users expect faster, safer, and more accessible website experiences. This means quick-loading pages, a simple purchase process, and 100% security.  They are ready to purchase at any point in time, from any device, in any location — if they’re ready, you should be, too. Poor performance causes poor user experience, but also results in higher web development and operations cost, lower site conversions, poor rankings for organic and paid search, and insufficient infrastructure and scale for traffic spikes. And for many eCommerce sites, poor performance stems from too much content, unoptimized files, and chatty assets.

eCommerce website performance

Godiva, for example, represents modern eCommerce sites that rely on numerous and heavy components:

  • 2.3 MB of content
  • 209 assets
  • 54 javascripts
  • 29 HTML files
  • 67 domains

You can see from the content complexity shown below that the site is comprised of many different kinds of assets, and this contributes to a page load time of almost 6 seconds. Worse, for small businesses that don’t have a Godiva-level website buget, a site like this would take substantially longer to load.

eCommerce website performance

User Experience

You wouldn’t hire a slow, unresponsive sales rep to support your company, so why would your website be any different? It’s all about the customer (user) experience. Users want to access information immediately. They want ease-of-use. Their time is valuable. Truly! You may not be hearing these complaints directly from the customer, but website metrics don’t lie. Around 40% of website visitors will leave your site after 3 seconds; 80% of those will not return. What’s worse, they’ll share their negative experience with friends and in online reviews.

Loss in Conversions

eCommerce website performanceThe proof is in the profit: every additional 1 second added on to your load time results in a 7% loss in conversion (Aberdeen Group).

At that rate, for an eCommerce site making $5,000 a day, a 1-second delay would mean $127,750 a year in lost revenue.

Downtime is even worse. A few hours of downtime a month adds up to whole days of downtime per year, and thousands in lost revenue. An unhappy customer isn’t inclined to complete a purchase, and a customer that can?t access the site simply isn’t able to purchase – this can mean big loss, in revenue, lifetime customer value, and brand loyalty.

eCommerce website performance

Aside from lost customers and lost revenue, the secondary costs of flagging customer satisfaction includes increased customer maintenance cost, more support calls and emails, and more PR damage control.

Competitor Advantage

eCommerce website performanceVisitors will turn to your competitors after a negative website experience. Average shopping cart abandonment numbers are high enough already (~70%): add an unclear purchase path and a slow, error-riddled site, and the result is an unsustainably low conversion rate. If your competitor’s site is even 1 second faster than yours, they have the advantage. If your competitor’s site is easier to access through mobile devices, once again they have the advantage. For these reasons, smaller companies assume their sites can’t compete with the “big guys.” ? this isn’t true (just look into Yottaa!).

How the Ecommerce Industry is Performing Today

The eCommerce industry adapts quickly to digital advancements, but too often websites emphasize style over function. To examine how these developments affect performance, Yottaa tested the user experience on hundreds of eCommerce sites.

eCommerce website performanceWhen it comes to the most important baseline metric – page load time – the Mass Merchant sector (the big guys) had the fastest overall at 5,895 msec (5.895 sec).

Yet this is still almost 3 seconds slower than the average user expectations. The average for the whole field is 6-7 seconds. Some sectors, like Office Supplies, Automotive Parts, and Jewelry, top 8+ seconds.

These numbers reflect home page performance. The numbers are even worse on image-heavy secondary pages, such as catalog and product pages, or within shopping carts, where a higher level of interaction is required.Most eCommerce sites are growing. What we’re starting to see is an inability for site performance to scale alongside site growth.

Why are eCommerce sites slow?

eCommerce website performance

More components means more risk of slowdowns or errors. And today’s eCommerce sites have more components than ever before: a successful page load now depends on the execution of dozens of assets, the appropriate treatment of dozens of images, and numerous requests to unpredictable third party domains.

When looking at modern eCommerce sites, we see:

  • Upwards of 10 domains
  • Millions of page bytes, including heavy images, JavaScript, and CSS
  • Hundreds of assets

eCommerce website performance

A quick look at our data confirms that eCommerce sites rely on complex components and interactive features to provide the right brand identity and engaging customer experiences.

On average, they are 100KB larger, and have almost double the number of assets and domains delivering content. Unfortunately, these components actually degrade the customer experiences they?re supposed to create, by slowing down performance.

So, exactly how do these numbers translate to slower sites?

Let’s start with an example: looking at a sample of our apparel/accessories data, these web performance issues come to the surface in the form of overall page load time. Big eCommerce players like Brooks Brothers, Van, Bergdorf Goodman, and Toms are losing money because of site speed.

eCommerce website performance

As we’ve seen, the sheer amount of assets and required domains on eCommerce sites correlates to poor performance. While many browsers can render for speed, they can only handle so much when it comes to weighed-down sites. So in reality, the Time to Interact is longer for heavier eCommerce sites. Put simply – the more content, the slower the site. And here’s the proof:


eCommerce website performance

To meet user experience expectations, unoptimized eCommerce sites would have to be comprised of less than 250 KB of assets per page. Looking at our average, that means these sites would need to remove 1,000 KB to meet this expectation. 

eCommerce website performance

Javascript and CSS files are necessities in today’s sites: they are staple web development tools. But if they aren’t ordered properly, minified, inlined, or concatenated they can become a performance nightmare.

eCommerce website performance
Most websites require requests to separate domains to completely render a page. Your website might be hosted at your own, purchased domain, but your live chat widget, social sharing buttons, and Google Analytics snippet aren’t. Those components are fetched from other, individual domains before your page fully loads. eCommerce sites have little control over the performance of these third-party assets, which can have serious implications for site performance overall.

These are just a handful of common elements that impact ecommerce website performance; many others go unnoticed without proper monitoring and bottleneck identification. While there are a number of techniques to manually optimize your website (just see our Resources section to get started), what eCommerce sites need most is an automated solution that guarantees great performance at all times.

Solving the Problem

Today, there?s an increasingly complex set of challenges associated with delivering an excellent online experience, driven by the growing richness of web sites and mobile apps, and the explosion of mobile devices and browsers.

The key techniques to improve your website performance:

Reduce Number of Requests

  • Combine scripts and images using concatenation
  • Combine images and CSS with sprites
  • Employ data URIs

Reduce Asset Weight

  • Use Gzip
  • Minify scripts
  • Use lossy and lossless image compression

Employ Parallel Processing

  • Load 3rd party assets asynchronously
  • Use domain sharding
  • Use intelligent script loaders

You can do these manually, or you can let Yottaa take care of it.Yottaa is an enterprise-grade web performance automation service that provides end-to-end infrastructure for modern sites and applications.

Simply put: we can make your site performance better, and automate it, too. So you don’t have to solve these problems manually. For more information, read more on Site Optimizer or check out our Yottaa for Drupal Commerce solution.

For more information on how Yottaa is solving the eCommerce industry’s biggest challenge, you can check out more detailed data and customer successes here.

Additional Resources

11 Best Practices to Optimize Commerce Site Performance [SlideShare]

The Unstoppable Wave of eCommerce [Infographic]

The ROI of Website Performance: A Resources Guide

Yottaa 9 Tips for Benchmarking Your Web Performance Download


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