FREQUENTLY ASKED QUESTIONS

What is PageSpeed and why does it matter?

PageSpeed Insights is a Google tool that analyses website performance and returns a score from 0 to 100. It evaluates loading speed, interactivity and visual stability, based on the Lighthouse framework. A PageSpeed score has two dimensions: lab data (a simulation under controlled conditions) and field data (real data from Chrome users). For SEO, field data matters more — Google uses it in the ranking algorithm, not the lab Lighthouse score.

What PageSpeed scores mean — the rating scale

Score	Rating	SEO impact	Action priority
90–100	Good (green)	Full ranking potential	Maintain and monitor
50–89	Needs improvement (orange)	Moderate ranking restrictions	Worth improving within 3–6 months
0–49	Poor (red)	Significant ranking restrictions	Urgent technical action needed

What most commonly lowers PageSpeed on WordPress?

From my auditing experience, the most common causes of a low WordPress PageSpeed are: too many plugins loading their own CSS/JS on every page (even when not needed), images in JPEG/PNG format without compression, served without conversion to WebP/AVIF, no server-side caching (every request = full PHP-generated HTML), heavy sliders and galleries (Revolution Slider is a classic cause of LCP above 4s), and under-configured hosting (shared hosting at €5/month with slow TTFB).

A typical unoptimised WordPress site on a stock theme with 20 plugins scores 40–65 on mobile. After basic optimisation (WP Rocket or LiteSpeed Cache, WebP, lazy load, removal of unnecessary plugins) you can reach 70–85. Above 90 on mobile requires deeper work: Critical CSS, deferred JS, server optimisation or moving to a VPS with Redis cache.

PageSpeed and conversions — hard data

Google and Deloitte published a study (2020) showing that a 0.1-second improvement in LCP on retail sites translated to +8.4% in conversions and +9.2% in average order value. Amazon estimated that every 100ms of delay costs 1% in sales. These are not small numbers — for a store with €50,000 monthly turnover, improving load time from 4s to 2s can mean a 10–15% increase in conversions.

The mechanism is simple: a slow site raises the bounce rate (Google states that 53% of mobile users abandon a page that takes more than 3 seconds to load), and a higher bounce rate sends worse UX signals to the ranking algorithm, which indirectly affects positions. The circle closes: slow site = worse rankings = less traffic = fewer sales.

How to check your site's PageSpeed

The simplest tool is PageSpeed Insights (pagespeed.web.dev) — enter a URL and within 30 seconds you get a full report with the lab score, field data (if the page has sufficient Chrome traffic), and a list of specific recommendations with estimated time savings after implementation.

Additional tools: GTmetrix (waterfall chart — shows exactly which resource is blocking rendering), Chrome DevTools → Lighthouse (local test with network throttling option), WebPageTest (test from different locations and devices). Important note: always test with mobile simulation and slow network (4G) — this is the most accurate test for real users, and results are typically 30–40 points lower than desktop.

How much does PageSpeed optimisation cost and when does it pay off?

The scope and cost depend on the starting point and platform. Basic WordPress optimisation (cache, WebP, lazy load, removal of unnecessary plugins) costs €120–€350 as a one-off and can take a score from 50 to 70–75. Deep optimisation (Critical CSS, deferred JS, Server Push, migration to LiteSpeed VPS) costs €470–€1,200 — delivering mobile scores of 80–92.