By Aman Singh · · 8 min read
The test — what we measured and how
We tested 12 Australian small business websites: 6 built on WordPress (with typical setups — Elementor page builder, WP Rocket caching, managed hosting) and 6 built on Next.js deployed to Vercel. All sites had similar content weight. We ran each through Google PageSpeed Insights three times on mobile and averaged the scores.
The results were consistent. WordPress mobile scores ranged from 38 to 71. Next.js scores ranged from 88 to 98. Average gap: 35 points on mobile PageSpeed.
Why WordPress sites score lower on mobile
- Page builder CSS. Elementor, Divi, and WPBakery load their entire stylesheet on every page — including styles for elements not on that page. A 500KB CSS file for a page that uses 30KB of it is common.
- Plugin JavaScript. The average WordPress site has 20+ plugins. Each one can add render-blocking JavaScript that delays the page becoming interactive.
- Shared hosting latency. Most small business WordPress sites are on shared hosting. Time to First Byte is typically 400–800ms. Vercel's edge network delivers in under 100ms to Australian users.
- Unoptimised images. WordPress serves images in the format uploaded unless you install another plugin. Next.js has a built-in Image component that auto-converts to WebP and lazy-loads.
Why Next.js scores higher
- No unused CSS. A Next.js build ships only the CSS required for the page being rendered.
- No plugins. Every feature is written as code. No third-party JavaScript runs on the page unless you put it there deliberately.
- Edge delivery. Modern hosts such as Vercel and Cloudflare deliver pages from edge nodes close to the user — Australian visitors hit Sydney or Melbourne nodes, not a US data centre.
- Static generation. Most pages are pre-built as static HTML at deploy time. The server sends a complete page immediately — no PHP execution, no database query.
Does the PageSpeed gap actually affect Google rankings?
Google has used Core Web Vitals as a ranking factor since May 2021. The three metrics — Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), and Interaction to Next Paint (INP) — are directly measured by PageSpeed Insights. A site failing Core Web Vitals is flagged in Google Search Console under "Page Experience."
For local search — the main battlefield for Australian service businesses — Google uses mobile-first indexing. The mobile version of your site determines your ranking, not the desktop version. A score of 42 on mobile is not an aesthetic problem. It is a ranking problem.
Can you fix a WordPress site to score 90+?
Yes — with significant effort. The path: switch to a lightweight theme (GeneratePress, Astra), remove the page builder, add a caching plugin, move to a faster host (Kinsta, Cloudways), and optimise all images. Done properly, a WordPress site can reach 80–90+ on mobile.
The problem is this process often costs more than rebuilding from scratch — and the underlying WordPress overhead never fully disappears. A performance-optimised WordPress site at 88 is an achievement. A stock Next.js build at 94 is the starting point.
For the full platform comparison, see: WordPress vs custom website Australia (2026).
Frequently asked questions
Is WordPress slower than Next.js?
In most real-world configurations, yes. WordPress sites with page builders and standard hosting typically score 40–70 on mobile PageSpeed. Well-built Next.js sites score 88–98. The gap is caused by page builder CSS, plugin JavaScript, and hosting latency — none of which exist in a Next.js build.
Does PageSpeed score affect Google rankings?
Yes. Core Web Vitals (which PageSpeed measures) have been a Google ranking factor since May 2021. The effect is strongest in competitive categories where multiple sites have invested in content quality.
Can I make WordPress score 90+ on mobile?
Yes, but it requires significant effort: lightweight theme, no page builder, caching plugin, faster hosting, and image optimisation. A properly optimised WordPress site can reach 80–90+. A default Next.js build starts at 90–98 without any optimisation work.
Want to see this applied to your business?
We’ll design your homepage free, with your real business name and services, so you can judge the work before deciding anything.
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