Does page speed affect mobile and desktop rankings equally?

Google uses mobile-first indexing — your mobile page speed has more influence on rankings than desktop. Always check PageSpeed Insights scores for the Mobile tab specifically, and prioritise mobile fixes.

How much does a slow page actually cost in conversions?

Research from Google and Deloitte shows a 0.1-second improvement in mobile load time drives 8-10% more conversions for retail sites. For SaaS landing pages, the impact on trial signups is similarly significant. Every second of load time above 3 seconds costs real users.

I'm on Shopify / Squarespace — can I still improve speed?

Yes, but you're limited by the platform. Shopify: use a minimal theme, compress all product images, remove unused apps (each adds load). Squarespace: reduce the number of animations, limit font variations, and avoid embedding heavy third-party elements.

Page Speed for Founders: Why It Matters and How to Fix It

Every 100ms of additional page load time reduces conversions by roughly 1%. Google has used page speed as a ranking signal since 2010 for desktop and 2018 for mobile. Despite this, most early-stage products have significant speed problems that are entirely fixable without a full engineering sprint.

What Google Actually Measures

Google doesn't just measure raw load time. It measures Core Web Vitals — three specific user experience metrics that correlate with how pages feel to users:

LCP (Largest Contentful Paint): How quickly the main content of the page loads. Target: under 2.5 seconds.
INP (Interaction to Next Paint): How quickly the page responds to user interactions like clicks. Target: under 200ms.
CLS (Cumulative Layout Shift): How much the page layout shifts unexpectedly as it loads. Target: under 0.1.

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Measure your Core Web Vitals using Google PageSpeed Insights (pagespeed.web.dev). It gives you a field data score (real users) and lab data score (simulated). Fix field data issues first — those affect actual ranking.

The 5 Biggest Speed Killers (and Their Fixes)

1. Unoptimised Images

Images account for 60-70% of page weight on most sites. Fix: convert to WebP or AVIF format (40-60% smaller than JPEG/PNG), add explicit width and height attributes to prevent CLS, lazy-load images below the fold, and use a CDN that serves images from edge locations near your users.

2. Render-Blocking JavaScript

JavaScript that loads in the <head> delays the browser from rendering anything. Fix: move non-critical scripts to the bottom of the page or add defer/async attributes. Third-party scripts (chat widgets, analytics, ad trackers) are the worst offenders — load them after the main content.

3. No Caching Headers

If your server sends no cache-control headers, browsers re-download every asset on every visit. Fix: set cache-control headers for static assets (images, CSS, JS) to at least 1 year. Most hosting platforms (Vercel, Netlify, Cloudflare) do this automatically — check that yours does.

4. Not Using a CDN

If your server is in one location and users are distributed globally, distance adds latency. Fix: use a CDN (Content Delivery Network). Vercel and Netlify include CDN by default. Cloudflare can be added as a free CDN layer on top of any hosting.

5. Unminified CSS and JavaScript

Development code includes whitespace, comments, and long variable names that bloat file sizes. Fix: minify all CSS and JS before deploying. Modern build tools (Next.js, Vite, Webpack) do this automatically in production mode — verify your build pipeline is configured correctly.

Quick Wins You Can Do Today

Run PageSpeed Insights and fix the top 3 'Opportunities' listed
Install Cloudflare (free) in front of your existing hosting for instant CDN + caching
Compress every image on your homepage to WebP using Squoosh.app
Defer all third-party scripts (Google Analytics, Intercom, etc.) to load after the page
Remove unused CSS — tools like PurgeCSS identify it automatically