Updated October 2026. Website speed optimisation makes pages load and respond quickly, especially on phones using mobile data, which is how most Kenyans browse. Slow pages lose visitors before they see anything, and Google uses page experience signals, including Core Web Vitals, in ranking.
Who this guide is for: Business owners, publishers and developers whose sites feel slow on phones.
Contents
Measure first
- PageSpeed Insights shows lab scores and, for busier sites, real-user data.
- Search Console’s Core Web Vitals report groups slow URLs across the site.
- Test on a real mid-range Android phone over mobile data, not just office Wi-Fi.
The three Core Web Vitals
| Metric | What it measures | Good |
|---|---|---|
| LCP (Largest Contentful Paint) | How fast the main content appears | 2.5 seconds or less |
| INP (Interaction to Next Paint) | How fast the page responds to taps | 200 ms or less |
| CLS (Cumulative Layout Shift) | How much the layout jumps | 0.1 or less |
Fixes that matter most
- Images: resize to the size actually displayed, convert to WebP or AVIF, and lazy-load images below the fold.
- Caching: page caching (for example LiteSpeed Cache on LiteSpeed servers) and browser caching.
- Fewer scripts: remove unused plugins, chat widgets and trackers; delay non-essential scripts.
- Fonts: limit font families and weights, preload the main one, use font-display swap.
- Hosting: a server close to your users with enough resources; overloaded shared hosting undoes every other fix.
- Layout stability: set width and height on images and ad slots so content does not jump.
Mobile layout problems
Speed is half the story. Check that text is readable without zooming, buttons are large enough to tap, menus work with one thumb and nothing overflows the screen sideways.
Ads and speed
Display ads are a common cause of slow, jumpy pages. Reserve space for each ad slot and limit the number per page.
Key terms in website speed optimisation
- LCP
- Largest Contentful Paint: when the main content appears.
- INP
- Interaction to Next Paint: how quickly the page responds.
- CLS
- Cumulative Layout Shift: how much the layout jumps.
- Lazy loading
- Loading images only when they come into view.
- Page cache
- A saved copy of a page served without rebuilding it.
- WebP and AVIF
- Modern image formats smaller than JPEG.
Questions to ask before you hire help with website speed optimisation
- Which pages will be measured?
- Will tests include real mobile devices?
- Which plugins or scripts will be removed?
- Is the hosting adequate?
- How will results be checked?
Website speed optimisation: mistakes to avoid
- Chasing a perfect lab score while real users still wait.
- Installing several speed plugins at once.
- Uploading full-size phone photos.
- Ignoring third-party scripts.
- Forgetting to re-test after updates.
How to measure success
Track the share of URLs passing Core Web Vitals in Search Console, plus bounce rate and conversions on mobile.
What is different in Kenya
Many Kenyan visitors use mid-range Android phones on mobile data where speeds vary. Test from Kenya where you can, and consider a CDN with nearby edge locations so images and files travel a shorter distance.
Costs to plan for
Costs include better hosting if needed, a CDN, image optimisation tools and developer time.
A worked example
Imagine a hardware shop's WordPress site that takes a long time to load on a phone. PageSpeed Insights shows a huge home page banner image, several sliders and a dozen plugins. The developer resizes and converts images to WebP, replaces the slider with a single image, removes unused plugins, and turns on LiteSpeed Cache. Fonts are cut to one family with two weights.
Width and height are added to product images so the layout stops jumping. The site is re-tested on a mid-range Android phone over mobile data and the main content now appears much sooner. Over the next weeks, Search Console's Core Web Vitals report moves more URLs into the good group. The shop then sets a rule: every new plugin must be tested for speed before it stays installed.
Website speed optimisation: a 30-day starter plan
- Week 1: measure key pages and list the slowest templates.
- Week 2: compress images and enable caching.
- Week 3: remove unused scripts and fix layout shifts.
- Week 4: re-test and watch the Core Web Vitals report.
Summary
This guide to website speed optimisation covered: Measure first; The three Core Web Vitals; Fixes that matter most; Mobile layout problems; Ads and speed. Work through them in order, measure as you go, and keep every fact tied to an official or first-hand source.
Sources
- web.dev: Core Web Vitals (accessed October 2026)
- PageSpeed Insights (accessed October 2026)
Need this done for you? See our website services.
Website speed optimisation: frequently asked questions
Does website speed affect Google rankings?
Yes, page experience including Core Web Vitals is one of many ranking signals, and slow pages also lose visitors.
What is a good PageSpeed score?
Focus on passing Core Web Vitals with real-user data rather than chasing a perfect lab score.
What is the quickest speed win on WordPress?
Usually compressing and resizing images and turning on page caching.
Why is my site fast on Wi-Fi but slow on my phone?
Mobile data is slower and phones have less processing power, so heavy pages suffer more.
Does a CDN help in Kenya?
A CDN with nearby edge servers can speed up delivery of images and files.
Does page builder use slow down WordPress?
Some page builders add heavy code; lighter themes and blocks are usually faster.
How often should I test speed?
After every major change and monthly as routine.
Will a faster site increase sales?
Speed removes a reason to leave; combine it with a clear offer and checkout.
Related
Want help with this?
Tell us about your business in a few lines. We reply within one working day.
Prefer WhatsApp? +254 790 939 404 · We reply within one working day.