Landing Page Leaks · Load Time (Signal 4)
Boost Landing Page Speed to Increase Paid Ad Conversions
Slow load time is the only conversion leak that costs you before the visitor has seen anything. A visitor who abandons during load is recorded as a bounce before your headline, your proof, or your CTA ever had a chance to work. Fix this before optimising anything else.
What the data says about speed and conversion
Two studies with real methodology behind them (not the widely-circulated figures that have no traceable primary source):
Portent, 2022 - 100M+ page views across 20 B2B and B2C sites
B2B lead-generation pages loading in 1 second convert at roughly 3x the rate of pages loading in 5 seconds, and 5x the rate of pages loading in 10 seconds. At anything above a 5-second load, conversion rate drops to roughly half of a fast-loading equivalent. The full analysis is at Portent: Site Speed is (Still) Impacting Your Conversion Rate.
Deloitte/Google, 2020 - 37 retail, travel, and lead-gen brands
A 0.1-second improvement in mobile load time increased retail conversions by 8.4% and travel conversions by 10.1%. Retail consumers spent 9.2% more per order at the same improvement. The methodology and full findings are in the Milliseconds Make Millions report (Think with Google / Deloitte Digital).
2024 Web Almanac - HTTP Archive, real CrUX data
Only 38% of mobile home pages passed all Core Web Vitals in 2024, according to the 2024 Web Almanac (Performance chapter). That means more than six in ten mobile landing pages are failing Google's real-world performance thresholds - including many that have been “optimised.”
The thresholds that matter: LCP
Largest Contentful Paint (LCP) measures when the main content element - usually the hero image or headline - becomes visible. For a landing page, this is the moment the visitor can actually evaluate whether they are in the right place.
LCP under 2.5s
Good
Most visitors see your offer quickly. This is the target for paid traffic landing pages.
LCP 2.5s–4s
Needs improvement
You are losing impatient visitors. Fix before scaling ad spend.
LCP above 4s
Poor
You are bleeding conversions and Search ranking. This is the first thing to fix.
Check your LCP free at pagespeed.web.dev. Enter your landing page URL. Takes under two minutes. Run the mobile test - not just desktop.
The 4 most common causes of slow LCP
Uncompressed hero image
Convert to WebP format. Compress to 80% quality - indistinguishable from lossless at normal screen sizes. Serve responsive images (srcset) so mobile gets a smaller file than desktop. A 2MB PNG hero becomes 150–200KB WebP. This alone fixes LCP in most cases.
Render-blocking third-party scripts
Chat widgets, ad pixels, analytics tags, and A/B testing tools loaded in the <head> block rendering until they resolve. Audit with Chrome DevTools Network tab. Defer or async-load any script that is not required for initial render. Each third-party tag adds latency you cannot control.
No CDN
Serving static assets from a single origin server adds round-trip latency for visitors not near that server. Cloudflare is free for most sites and routes assets from edge locations geographically close to the visitor. Enable it before any other infrastructure change.
Slow server response (TTFB above 800ms)
Time to First Byte above 800ms means the server itself is slow before the browser has received anything to render. Causes: shared hosting under load, unoptimised server-side rendering, no caching. Check TTFB in PageSpeed Insights. If it is above 800ms, hosting tier or server-side caching is the fix, not image compression.
Fix sequence: highest priority first
Speed optimisation has diminishing returns. Getting from 6s to 3s is usually straightforward. Getting from 3s to 1.5s requires code splitting, critical CSS, and font subsetting. Start with the high-impact, low-effort fixes.
- 1.Compress hero image to WebP at 80% quality
- 2.Add lazy loading to all below-fold images (loading="lazy")
- 3.Enable Cloudflare or equivalent CDN
- 4.Defer or async-load all non-critical third-party scripts
- 5.Check TTFB - if above 800ms, address server response before frontend
- 6.Remove redirect chains (each redirect adds a full round-trip)
Re-run PageSpeed Insights after each change to confirm the LCP improvement before moving to the next fix.
Load time and Google Ads Quality Score
Google's Landing Page Experience score - one of the three components of Quality Score - includes page load speed as a factor. A slow landing page reduces Quality Score, which raises your cost-per-click and lowers your ad position. This means slow load time costs you twice: lower conversion rate on the traffic you receive, and higher CPC to get that traffic in the first place.
Check your landing page's Quality Score in Google Ads under Keywords → Columns → Quality Score components. If Landing Page Experience shows “Below Average,” load time is a likely contributor.
Frequently asked questions
How does page load time affect conversion rate?
Multiple studies show a consistent relationship. Portent's 2022 analysis of 100M+ page views found that B2B lead generation pages loading in 1 second have a conversion rate roughly 3x higher than pages loading in 5 seconds, and 5x higher than pages loading in 10 seconds. A 2020 Deloitte/Google study of 37 brands found that a 0.1-second improvement in mobile load time increased retail conversions by 8.4% and travel conversions by 10.1%. The mechanism is simple: a visitor who abandons during load is recorded as a bounce before they have seen your headline, your proof, or your CTA.
What is a good page load time for a landing page?
Google defines good Largest Contentful Paint (LCP) as under 2.5 seconds; 2.5–4 seconds needs improvement; above 4 seconds is poor. For paid traffic landing pages specifically, aim for LCP under 2.5 seconds on mobile - this is the device your visitors are most likely using. According to the 2024 Web Almanac (HTTP Archive), only 38% of mobile home pages currently pass all Core Web Vitals. If your page is in the 62% that fail, load time is a conversion blocker before any copy or layout issue is reached.
How do I check my landing page load time?
Use Google PageSpeed Insights (free, pagespeed.web.dev) - enter your landing page URL and it returns your LCP, FCP, and Core Web Vitals scores for both mobile and desktop, using real Chrome user data if available. For a more detailed waterfall view, use Chrome DevTools (Network tab, throttle to Fast 3G to simulate mobile). The LCP figure is the most actionable single metric for landing pages.
What causes slow LCP on a landing page?
The four most common causes: (1) uncompressed hero image - a 2MB PNG in the first viewport will dominate LCP; (2) render-blocking scripts - third-party tools (chat widgets, analytics, ad pixels) loaded in the head block render until they resolve; (3) no CDN - serving assets from a single origin server adds round-trip latency for distant visitors; (4) server response time (TTFB) above 800ms - hosting tier or unoptimised server-side rendering. Image compression is often the simplest intervention when the hero image dominates LCP.
Does page speed affect Google Ads Quality Score?
Yes. Google's Landing Page Experience component of Quality Score includes page load speed as a factor. A slow landing page can reduce Quality Score, which increases your cost-per-click and reduces your ad position. This means slow load time costs you twice: lower conversion rate on the traffic you receive, and higher CPC for that traffic. PageSpeed Insights flags this explicitly in its Quality Score impact section.
Find the leak on your page
The free Nebula audit checks all 9 signals including load time. The $97 One-Leak Repair Sprint supplies a tailored change for one high-confidence page-level finding. You or your developer implements it, and the 30-day re-audit verifies the page condition. It does not promise conversion lift.