How Page Speed Affects E-commerce Conversion Rates

Speed and revenue are connected

A 2017 Akamai study found that a 100-millisecond delay in page load time reduced conversion rates by up to 7%. Google’s own research shows that as page load time increases from 1 second to 3 seconds, bounce probability increases by 32%.

For e-commerce stores, slow pages mean lost sales.

What slows down product pages

Product pages have unique performance challenges:

• Large product images: High-resolution photos without proper compression or responsive sizing.
• Third-party scripts: Review widgets, chat tools, analytics, and retargeting pixels all add load time.
• Unoptimized fonts: Custom fonts that block rendering until they download.
• Heavy JavaScript bundles: Single-page app frameworks that ship large bundles for simple pages.

What to measure

The metrics that matter most for e-commerce:

• Largest Contentful Paint (LCP): How long until the main product image appears. Target: under 2.5 seconds.
• First Input Delay (FID): How long until the page responds to interaction (like clicking “Add to Cart”). Target: under 100ms.
• Cumulative Layout Shift (CLS): How much the page moves around during load. Target: under 0.1.

How to find your problem areas

SiteCurl’s performance checks measure load time, resource sizes, and rendering metrics across your pages. Scan your top landing pages and product pages to find what’s slow and why.

The report breaks findings into actionable items: which images need compression, which scripts are blocking rendering, and where layout shifts are happening.

Start with your highest-traffic pages

You don’t need to optimize every page at once. Start with your homepage, top category pages, and best-selling product pages. Those carry the most revenue impact.