Originally published December 2025. Updated November 2026 to replace First Input Delay with Interaction to Next Paint, add how media slows pages down and customer results, and fix product names.
Key takeaways
Performance is revenue: A 1-second delay in page load time can reduce ecommerce conversions by up to 20%.
Measure first: start with your Core Web Vitals, LCP, INP and CLS, to find your performance baseline.
Go headless for speed: Monolithic platforms are a common bottleneck. A headless CMS is the strategic fix.
Automate media: Large images slow sites down. Amplience Dynamic Media creates every image size and format from one master asset, on demand.
To increase website speed, start with media, which makes up most of the page weight on retail sites. Measure your Core Web Vitals, serve right-sized images in modern formats from a CDN, cut scripts and redirects, and use a headless CMS. Faster pages convert better, rank higher and bring shoppers back.
Website speed isn’t a luxury, it’s a necessity to win in eCommerce. A fast and responsive website leads to better user experiences, higher conversion rates, and increased customer loyalty. Conversely, a slow website can drive potential customers away into the arms of your competitors, significantly hurting your bottom line.
Read on to discover how you can improve website speed, the importance of using a headless CMS for speed optimization, and actionable strategies that will help to improve website performance, and ultimately, business results.
Why does site speed matter for ecommerce?
Website speed, or page load time, is a critical factor that impacts some very key aspects of an eCommerce business:
User experience (UX): A slow website frustrates potential customers, increases the likelihood of them bouncing and reduces repeat visits. A seamless, fast browsing experience encourages customers to stay on your website for longer, increases engagement and vastly improves the likelihood of conversions.
Conversion rates: Google research found that a one-second delay in mobile page load time can reduce conversion rates by up to 20%. And every second counts when you’re trying to drive customers to purchase.
Search engine optimization (SEO): Page load speed is a direct ranking factor according to Google, meaning faster websites are favored in search engine results. By optimizing your page load speed, you increase organic visibility, drive more traffic, and potentially more sales.
Mobile optimization: With the rise of mobile shopping, ensuring fast load times on mobile devices is critical. Users browsing on mobile are particularly sensitive to delays and are more likely to abandon a slow-loading site.
How does a headless CMS help site speed?
One of the most effective ways to optimize website performance is by using a headless content management system (CMS). A headless CMS decouples the frontend (what the user sees) from the backend (where the content is managed), giving eCommerce teams more flexibility and control over how content is delivered.
Here are some of the key benefits of using a headless CMS to optimize site speed:
Faster content delivery: A headless CMS allows content to be distributed via APIs to multiple channels and devices, making it easier to serve content quickly without loading unnecessary backend resources.
Better control over user experience: Because the frontend and backend are separated developers can tailor the user experience more precisely, optimize performance for different devices, and streamline content delivery for faster load times.
Scalability: As your eCommerce business grows, a headless CMS can scale more efficiently. It’s specifically designed for handling traffic spikes without compromising speed, which is crucial for high traffic eCommerce websites during peak times like Black Friday or holiday sales.
Improved mobile performance: A slow mobile site directly (and negatively) impacts conversions. Headless CMS platforms are a powerful solution, as they allow eCommerce businesses to create optimized, mobile-first experiences that load quickly and are responsive on all devices. Given that consumers are increasingly shopping from their smartphones, this is particularly important.
What are the best ways to speed up an ecommerce site?
While using a headless CMS can provide a solid foundation for site speed optimization, there are other actions that eCommerce teams can take to increase website performance. Here are some actionable strategies:
1. Monitor and improve Core Web Vitals (CWV)
Before you can optimize, you must measure. Google’s Core Web Vitals are the non-negotiable metrics for user experience and SEO. Your optimization efforts should focus on improving:
Largest Contentful Paint (LCP): how fast the page’s main content loads. Aim for 2.5 seconds or less. On commerce pages, the hero or product image is usually the largest element.
Interaction to Next Paint (INP): how quickly the page responds when someone clicks, taps or types. Aim for 200 milliseconds or less. INP replaced First Input Delay as a Core Web Vital in March 2024.
Cumulative Layout Shift (CLS): how much the layout jumps as it loads. Aim for 0.1 or less.
INP looks at every interaction during a visit, not just the first, so heavy JavaScript anywhere on the page can hurt it. To improve it, break long tasks into smaller ones, defer work that doesn’t change what the shopper sees, and keep pages light so the browser has less to process.
Use Google’s PageSpeed Insights to get your baseline score. This will tell you exactly where to focus your efforts.
2. Optimize images and media files
Images and video make up most of the page weight on retail sites, so media is usually the biggest lever on speed. A DAM on its own won’t fix it. It stores and organizes your assets, but it serves whatever you upload, so a 3MB master can end up on a shopper’s phone.
Amplience Dynamic Media is the delivery layer that closes that gap. You store one high-quality master in Amplience DAM, and every size, crop and format is created on demand from the URL. With automatic format selection, browsers get the lightest format they support, and AVIF through Amplience Accelerated Media offers 20 to 30 percent better compression than WebP.
For a retailer with 100,000 SKUs, six image variants per product would mean more than 600,000 files to produce and keep current. With Dynamic Media, it’s one master per SKU, and a new channel is a new URL template, not a new production run. Correctly sized images also help CLS, because the page can reserve space before they load.
3. Use content delivery networks (CDN)
A CDN is a network of servers linked together to deliver content as quickly and securely as possible. It is a foundational part of improving ecommerce website speed globally, as it helps to reduce latency and accelerate load times by serving content from a server physically closer to the user.
Amplience delivers media through multiple CDNs, including Akamai, Cloudflare and Fastly, with caching from the browser to a global edge network, so media stays fast during peak trading.
4. Minimize HTTP requests
Every time a user loads a page, their browser makes multiple HTTP requests to retrieve various files like images, scripts, and stylesheets. Reducing the number of HTTP requests can drastically improve page load times.
Combine multiple CSS and JavaScript files into single files to reduce the number of files that need to be loaded and to improve website performance.
5. Improve server response time
The time it takes for your web server to respond to a request can have a significant impact on page load times. A slow server response time can lead to delays before any content is even delivered to the user.
Ensure that your hosting environment is optimized for speed and optimize your database queries to reduce delays in fetching product information or processing transactions.
6. Reduce redirects
Website redirects create additional HTTP requests which negatively impact performance. By running a site scan, you can establish how many redirects your website has and reduce them as much as possible, leaving only the critical ones. It’s advised to keep redirects to a minimum or, for optimum performance, eliminate them entirely.
7. Monitor and continuously optimize
Improving website speed isn’t a task you can complete once and just forget about, it requires ongoing monitoring and optimization. By conducting regular performance audits, you can catch and address issues before they impact your users.
How does a faster site increase revenue?
A fast, well-optimized eCommerce website doesn’t just load quickly and improve the customer experience — it directly influences your bottom line. Here’s how website speed impacts business results:
Higher conversion rates: Faster load times reduce bounce rates and increase the likelihood of users engaging with your content and completing a sale. Every millisecond counts in driving potential customers to purchase.
Improved SEO rankings: A website with fast load times ranks higher in Google search results, leading to more organic traffic and better customer acquisition.
Increased customer loyalty: A website that loads quickly provides a better overall user experience, encouraging customers to return for future purchases.
Increased revenue: Faster sites have been shown to result in higher average order values (AOV) and more repeat customers, leading to increased revenue.
Amplience customers show what that looks like. DFS reports a 60% conversion uplift. Clarks improved site speed by 44%, lifted add-to-basket rate by 79% and grew conversion by 19%. The Gym Group increased site speed by 40%, and John Lewis moved more than 70 million images to Amplience Dynamic Media.
Where should you start?
Start by measuring your Core Web Vitals, then fix the biggest lever first, which for most retailers is media. Add a headless CMS, a CDN, and a habit of cutting scripts and redirects, and keep monitoring as your site grows.
To see how Amplience can help you build a high-performance ecommerce experience, book a demo today.