Performance Testing: Tips for E-commerce Site Performance

The COVID-19 pandemic has been an accelerator of growth for online shopping and e-commerce. But are your website pages loading fast enough for impatient customers? This article shares some practical tips and metrics to test and measure the performance of your e-commerce website.

Author: Ben Blomberg, Dotcom-Monitor,

As 2020 comes to an end, online retailers everywhere are gearing up for some of the busiest shopping days of the year. In any “normal” year, organizations would probably have already tested their servers, applications, and websites sites by late summer/early fall, ensuring that they can handle the expected influx and spikes in online shoppers in the months to come. However, add a global pandemic into the mix and you have got yourself the makings of a very uncertain and extremely busy online shopping season.

Performance Testing: Tips for E-commerce Site Performance

The COVID-19 pandemic has pushed everyone to reassess how and where business gets done. Organizations that may have started gearing up for the holiday season in the fall, shifted their testing schedule to earlier in the year, as more people were staying home and opting to shop online where possible. For example, a study conducted by Inmar Intelligence earlier this year showed that almost 80 percent of US consumers shopped online for their groceries, which was up from 39 percent pre-pandemic. And that trend is likely to continue into 2021 because consumers have gotten used to the convenience of having their groceries delivered, as well as the fact that a vaccine for COVID-19 is still probably months away from being approved and distributed to the public.

So, with the strong possibility of more online traffic on the horizon, where should an organization put their efforts? The obvious answer is where your customers are going to be, whether that is an e-commerce storefront, user application, or portal, it needs to perform flawlessly. The piece that most often gets ignored is any third-party APIs or elements your sites and applications use also need to be tested.

E-commerce Page Performance – Page Load Speed

One of the easiest ways to improve customer retention is ensuring your pages load in a timely manner. We have all seen and heard the statistics. If your site doesn’t load within 3 seconds or less, a visitor is likely to bounce. It is as simple as that. People are very inpatient creatures, if you haven’t already noticed that.

There are many factors that can contribute to slow loading pages, such as large images (or using too many images), JavaScript, CSS, HTML, and any other multimedia, like videos, for example.

Running a page speed test is a great way to quickly get a baseline of your page load speed and to identify what elements could be slowing them down. And when we talk about running a page speed test, we are not talking about a speed tests that you would run with your local ISP that shows upload/download metrics. You want to use a tool that can run tests to your pages from different locations around the world. Or more importantly, running tests from where your visitors are geographically located. This will give you results from a visitor’s perspective and show you the specific elements that could be hindering performance.

Page Load Speed – Metrics to Watch

As we have previously mentioned, there are a lot of factors that go into why a page performs the way it does, but here are a few of the main metrics that you should be on your watchlist after running a test:

First Contentful Paint (FCP)

The FCP is the time it takes the browser to render any content. This could be an image, text, etc. For example, this would typically be a website header or a site’s navigational menu.

Speed Index

The Speed Index measures how fast the elements above the fold are rendered. The quicker images are displayed, the better. This is metric is especially important for a visitor’s perception of fast page load time. If they can see content loading, the more likely they will stay on the page.

Time to Interactive (TTI)

TTI is the moment when elements have loaded to the point where the page will respond to user input or interaction.

First Meaningful Paint (FMP)

FMP is typically defined as when the primary page content is visible or painted on the screen.

Max Potential First Input Delay (FID)

The Max Potential FID measures how quickly your site responds to a user input (clicking a button, for example) and when the browser responds to that action.

E-commerce Site Performance: Load Testing

Now that you have got an idea about general web page load speed and what on-page elements need to be improved, the next step is running performance tests. It is not just going to be a few visitor’s hitting your site during the Black Friday to Cyber Monday shopping period. Depending on your business, it can be hundreds or thousands of concurrent visitors, all from different parts of the world. Your site must stand up to the demands of all these visitors and the best way to do that is to carry out load testing, or even stress testing, of your site. It is a proven method that allows you to see how your system resources, bandwidth, CPU, disk I/O, etc., respond to large spikes of traffic. And knowing where performance bottlenecks occur gives you the insight you need to fix those elements.

A performance testing solution like LoadView can help with just that. Unlike some other solutions in the market that require you to install them on a local machine, LoadView is cloud-based, so you can quickly spin upload injectors from multiple regions around the world and load test your websites, applications, APIs, and more.

E-commerce Paths to Purchase: Scripting Made Easy

Where other tools make you manually create your test scripts line by line, the LoadView solution includes a point and click scripting tool called the EveryStep Web Recorder, so you don’t even really need to know how to code to create scripts. You just browse, select, click, and navigate like your customers would, and the script is saved automatically. The best part is that the recorder works with nearly all web application technologies and supports all the popular desktop browsers and mobile devices. Once your script is created, you use it to run your load tests. For example, an e-commerce site should be scripting and testing the following:

  • Product pages
  • Searching for items or products
  • Putting items in a cart or removing items from the cart
  • Creating customer accounts
  • Checkout process

The key to great performance testing is being able to simulate the real-world conditions your visitors will experience. The earlier you can drill into any performance defects, the better their experience will be. Performance testing can give you insights to unsuccessful transactions, errors, latency, throughput metrics, how many concurrent users your site can handle, plus much more. And you can sleep better knowing that with taking action to fix any potential problems, there is a good chance that you will not be getting any early morning complaints telling you the site is down.

Don’t be Another Black Friday Statistic

Global retail e-commerce is a huge business. In fact, Statista projects e-commerce sales to be over $4.2 billion in 2020. It seems that every year there is a notable company that experiences a website slowdown or complete crash and ends up making the news in the most unflattering way. This year, with the obvious focus on online shopping for most consumers, it is even more critical than ever for organizations to test their applications, sites, servers, third-party APIs, etc. Assume that any web resource on your page that could go wrong, goes wrong. Any outage means lost sales, revenue, and a customer’s trust and loyalty with your brand. Test early and often and save yourself some time from having to fix problems and give your customers the user experience they deserve.

About the Author

For the last 15 years, Ben Blomberg has worked in various technical marketing roles, from B2B technology resellers and distributors to data recovery and performance testing/monitoring SaaS platforms, focused on enhancing and promoting brand recognition to drive customer engagement.

Contact if you want to contribute quality software testing and software quality assurance content on this website.

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