Slow stores lose customers, and slow checkouts lose orders. Before you change anything, find out where time is lost. This guide shows where to focus first, based on the problems that come up most often in ecommerce projects.
Product pages: images are often the slowest part
- Serve images at the size they are shown, in modern formats, not one large file scaled down in the browser.
- Load images below the fold only when the visitor scrolls near them.
- Load the main product image first, since it is usually the largest element on the page.
Checkout: each extra step costs orders
Checkout speed is not only about loading time. It also depends on the number of steps and required fields. Guest checkout, saved payment methods and short forms reduce drop-off, even when pages load at the same speed.
Build pages ahead of time where you can
Product and category pages that do not change for each visitor can be built in advance and refreshed when content changes. Serving a ready page is faster than building it on every request, and this is often the biggest single gain. Companies in the UAE working on ecommerce performance can see how we deliver it locally on our [ecommerce development in Dubai](/dubai/ecommerce-development) page.
Measure with real visitor data
Lab scores help you catch problems during development. Real visitor data, from real phones and networks, shows what shoppers actually experience.
We illustrate ecommerce performance with a documented example: see the [ecommerce storefront concept](/case-studies/ecommerce-platform). Related reading: [Scaling Modern Web Applications Without a Rewrite](/blog/scaling-modern-web-applications).
A simple order for performance work
- Measure the current pages with real data.
- Fix the product image and the checkout first.
- Test under load before the next busy sale.
Start with measurement, fix the checkout first, then test under load before a sale. If your store needs performance work, read about our ecommerce development service.
Start with measurement, not guesswork
Most slow stores are slow in one or two places. Measure real visitor experience first, using field data where it is available, then profile the server and the front end separately. Changing five things at once makes it impossible to know which change helped.
Images and media
Images are the most common reason product pages are heavy. Serve modern formats, size each image to the slot it fills, and lazy-load anything below the fold.
Give every image explicit dimensions so the layout does not jump while it loads. Product galleries often fetch full-resolution zoom images on the first render; load the zoom asset only when a shopper asks for it.
Third-party scripts
Tag managers, chat widgets, review widgets and testing tools each add requests and main-thread work. Review them regularly, and remove any script whose owner cannot say what it measures. Load the rest after the page is interactive, and never let a third-party script block the checkout.
Checkout and the database
Category and product pages can usually be cached aggressively. Cart and checkout usually cannot. Keep those requests short: avoid heavy queries in the cart path, and move recommendation work and non-critical checks out of the request where the business can accept a short delay.
Performance work pays off most on pages that earn revenue. Start with the checkout and the highest-traffic landing pages, then widen the scope once those are under control.
Sector context changes ecommerce performance considerably, so see how we approach [retail software](/industries/retail).
