Consider the following:

  • Four in ten Americans leave a mobile shopping site if it takes longer than three seconds to load.
  • Amazon claims that a page load slowdown of one second could result in $1.6 billion fewer in sales.
  • Google says that a slowdown of four tenths of a second would result in 8 million fewer searches per day (with a corresponding decrease in ad views).

Many users are relatively impatient, and the speed of a website, especially in terms of page load times, are a huge factor in bounce rates and shopping cart abandonment. Because profit margins in eCommerce are small, reducing bounce rates and the likelihood of a user abandoning his or her cart is crucial. When you improve on and optimize the performance of your site, you are improving the efficiency of your resource usage.

One way of improving the performance of your eCommerce site is to implement and begin using HTTP/2, the first new version of the HTTP protocol (which governs the connection between your servers and your visitor’s browsers) since 1999. In short, the goal of HTTP/2 is faster websites for everybody.

Some sites will weigh the benefits of adoption against the costs of implementation (primarily due to changes in web server configuration) and conclude that delaying the move to HTTP/2 would be a good idea. For your eCommerce site, however, it’s clear that moving sooner rather than later is crucial for business success.

Backward Compatibility

While more and more browsers are supporting HTTP/2, they will still support HTTP/1.1. As such, you could choose to change nothing to your existing site. However, if you do not implement HTTP/2, your website, even if it were once well-optimized, will begin to lag when compared to those that have made the transition. In addition, your site will display to users as unsecure and be penalized with regards to search engine rankings.

What Makes HTTP/2 Good for Commerce Sites?

Generally speaking, all websites would benefit from using HTTP/2, especially in terms of page load speeds, but eCommerce sites are especially good candidates for taking advantage of the strengths of HTTP/2.

eCommerce Site Content Patterns Aligns with HTTP/2 Strengths

Your eCommerce site is probably resource- and image-heavy, which contributes to its slower load times. In addition to displaying lots of product images, your site most likely contains lots of pages for product descriptions, ordering/checkout, site policies, and so on.

With HTTP/1.1, the best practice was to consolidate files as much as possible (for example, consolidating your style sheets or minimizing the number of scripts your site calls), since each resource required its own call, and multiple requests stacked up behind each other. However, with the multiplexing ability of HTTP/2 (which is the practice of sending and receiving multiple HTTP requests asynchronously via a single TCP connection), having a queue build up is no longer an issue. With HTTP/1.1, all resources must wait for the current request to complete before any further action can be taken, but with HTTP/2, multiple requests can be handled simultaneously. In the end, it takes much less time for the browser to receive all resources it needs build the site.


Multiplexing isn’t just a boon for pages loading lots of images–it can also assist with faster downloads of any of your site’s resources, including render-blocking assets such as Cascading Style Sheets and JavaScript files. Rather than creating large files that apply to multiple pages of your site (which is the current best practice, since this minimizes the number of HTTP calls your site needs to make), you can create style sheets and scripts that are more specialized. For example, you might have a set of resources that are called only when a user navigates to product pages and a separate set of resources that are called when a user navigates to content pages such as shipping policies, privacy notices, and so on.

eCommerce Site Features Aligns with HTTP/2 Requirements

Possibly the most difficult aspect of the transition to HTTP/2 for a lot of websites will be complying with the requirement to run the site over a connection secured via Transport Layer Security (TLS). However, you have probably implemented  SSL/TLS on some of your pages to comply with things like the Payment Card Industry Data Security Standard (PCI DSS), a set of requirements imposed on businesses that handle major branded credit cards (such as Visa, MasterCard, American Express, and Discover). As such, moving to TLS for all pages of your site, as required by browsers currently supporting HTTP/2, would not be as drastic a change as it otherwise would be.

eCommerce Sites’ First Party Content, Domain Control, and Use of CDNs

The majority of the content served up by your eCommerce site is first party, such as product images and descriptions, checkout pages, and written text such as site policies, with little space devoted to advertisements. As such, most data requested by your users comes from the few domains that are under your direct control (as opposed to an advertising widget that embeds code written by an affiliated third party).

Because you have control over a majority of your content and how it is served, you essentially have control over a majority of the HTTP/2 implementation process. The work required for HTTP/2 implementation includes changes to web browsers and servers, but since most major browsers already support HTTP/2, that leaves you to ensure that your servers hosting your site are appropriately configured.

However, many eCommerce sites use some combination of private hosting and Content Delivery Networks (CDNs) to help ensure quick load times of pages, and your site is probably no different. Luckily, all of the major CDNs (including Fastly, Akamai, and CloudFlare) already offer HTTP/2 support.

To Implement or Not?

While the time involved and cost of implementing HTTP/2 could be high, especially if your site is hosted by a vendor that has not yet implemented complete support for HTTP/2. However, given the relative impatience of users with regards to page load times on eCommerce sites, and the resulting lost in revenue due to slow page load times, you should seriously consider transitioning as soon as possible.

You can find up-to-date information on how to implement HTTP/2 by referencing the appropriate documentation for your particular servers, but here are some guides that will give you an idea of what is required:

For specific details about the performance of your eCommerce site, consider requesting Rigor’s free performance report. In addition to performance metrics, the report includes tests for HTTP/2 support.