How Page Speed Affects Conversion Rate: The Data

The business case for page speed

Most conversations about page speed focus on SEO ranking. But the more immediate business impact is on conversion rate. A faster page means more visitors who were going to convert actually do — without any change to your offer, pricing, or copy.

Key research findings

The data here comes from Google, Akamai, Deloitte, and Cloudflare studies — all using large sample sizes of real users, not lab simulations.

The 100 ms rule

Akamai's research on retail sites found that a 100 ms improvement in page load time corresponded to a 1% increase in conversion rate. That sounds small, but at $10 M annual revenue it's $100 K from a single performance optimisation.

The 1-second threshold

Google's research shows that as page load time increases from 1 second to 3 seconds, the probability of a mobile visitor bouncing increases by 32%. From 1 second to 5 seconds, bounce probability increases 90%. From 1 to 10 seconds, it's 123%.

Deloitte's retail study

Deloitte's 2020 "Milliseconds Make Millions" study across retail, travel, luxury, and lead generation sites found that a 0.1-second improvement in load time increased conversion rates by 8.4% for retail sites and 10.1% for travel sites, and increased average order value by 9.2% on retail.

The mobile gap

Mobile users are significantly less tolerant of slow pages than desktop users. Google data shows 53% of mobile site visits are abandoned if pages take longer than 3 seconds to load. Yet the median mobile page takes 15.3 seconds to fully load — a dramatic gap between what users will tolerate and what most sites deliver.

Industry benchmarks

Good and acceptable LCP thresholds by industry (75th percentile of field data):

• E-commerce: Good = under 2.0 s (users expect speed; competitors are fast)
• SaaS / B2B: Good = under 2.5 s (technical buyers tolerate slightly more)
• Publishing / Content: Good = under 3.0 s (readers will wait for content they want)
• Local / Small Business: Good = under 3.0 s (direct intent visitors are more patient)

These are competitive benchmarks, not Google's thresholds. To outrank competitors, aim for the top quartile of your industry, not just "good" by Google's standard.

The compounding effect

Page speed affects multiple parts of the funnel simultaneously: Google ranks you higher (more traffic), the landing page loads faster (lower bounce rate), the checkout or form loads faster (higher conversion), and the confirmation page loads faster (better first impression). A site that improves from the 3rd to 1st quartile in speed in its niche could see 30–50% more revenue from organic traffic through compounding gains across these stages.

Where to start

The highest-ROI improvements are almost always: eliminating render-blocking resources, optimising the LCP image, and improving TTFB with server-side caching or a CDN. Run a free ScanoraAI audit to see your current scores and get a prioritised fix list — sorted by impact, not just severity.