Pages on an e-commerce site should load in one second or less since site speed starts negatively impacting conversion rates when page load times exceed one second. An engineering team dedicated to improving e-commerce site speed at Walmart discovered this in 2012.

Today, achieving fast page load times on an e-commerce site is even more important. In 2012, e-commerce sales accounted for only 5% of US retail sales while, in early 2021, they [accounted for 15%](https://www.census.gov/retail/mrts/www/data/pdf/ec_current.pdf). As these percentages increase, so does the importance of making homepages, category pages, [product detail pages (PDP)](/content/blog/answers/product-detail-page/index.html), and [checkout pages](/content/blog/answers/time-to-interact/index.html) load fast.

## E-Commerce Conversion Rate Versus Site Speed

One of the first major companies to advocate faster page load times on e-commerce sites was Walmart. In 2012, [Chris Crocker](https://www.linkedin.com/in/cliffcrocker/), Walmart’s senior engineering manager responsible for site performance at the time, [presented a study](https://www.slideshare.net/devonauerswald/walmart-pagespeedslide/37) that showed how conversion rates sharply declined when pages took longer than one second to load.

Years before Crocker presented this data, [there was talk](https://news.ycombinator.com/item?id=273900) that every 100ms of latency cost Amazon 1% of profit. Whether this is true or not, it’s still true that page load time has a direct impact on bounce rate and conversions. [2018 data from Google](https://www.thinkwithgoogle.com/marketing-strategies/app-and-mobile/mobile-page-speed-new-industry-benchmarks/) confirms this.

Even though one second is the magic number, the average page load time for the average e-commerce site is [stuck between 3 to 5 seconds](https://www.moovweb.com/post/top-100-retailer-lighthouse-performance-score). To direct this issue, 7 of the 10 largest online retailers have switched to headless commerce.

## How to Improve E-Commerce Site Speed

### Switch to headless commerce

Adopting [headless commerce](/content/blog/headless-commerce/index.html) improves site speed while giving you more control over how you design e-commerce experiences. This is when you stitch together [microservices](https://resources.fabric.inc/blog/ecommerce-microservices-architecture) from various commerce software providers with [APIs](/content/blog/rest-apis/index.html). By doing this, elements of pages can load asynchronously since they are not being delivered from a single server, as is often the case with traditional, monolithic e-commerce setups.

Teespring, an e-commerce site that sells t-shirts and other apparel, [doubled conversions](https://www.youtube.com/watch?v=s3hDghdIiFY&feature=youtu.be&t=294) when it switched to a headless commerce setup. The distributed nature of the headless tech stack allows elements of its product pages, checkout pages, and other pages to load asynchronously, thereby helping pages load faster.

### Use performance testing tools

To test the current speed of your e-commerce site there are free tools you can use. These tools will quickly give you a baseline for the performance of your site. They also offer detailed suggestions for how you can improve site performance.

Performance testing tools that work for e-commerce sites include:

- [PageSpeed Insights](https://developers.google.com/speed/pagespeed/insights/)
- [Pingdom](https://tools.pingdom.com/)
- [GTmetrix](https://gtmetrix.com/)

Since testing individual pages with these free tools is cumbersome, many online retailers have engineering teams that use performance monitoring tools like [New Relic](https://newrelic.com/solutions/industry/retail-and-ecommerce-monitoring). This is a good option to consider if you are a mid-market brand or enterprise retailer.

## Key Takeaways

- Research from Walmart shows that pages on e-commerce sites must load in one second or less to ensure site speed does not impact sales and conversions.
- As e-commerce sales skyrocketed during the coronavirus restrictions (39% in 2021 Q1 compared to 2020 Q1) so too did the need to increase site performance.
- Adopting headless commerce technology, using performance testing tools, and using site monitoring tools can help you boost e-commerce site speed.
- You can use a headless CMS such as [fabric XM](/content/xm/index.html) to get started with headless commerce and improve site speed.