A slow website costs you customers before they read a single word. Most visitors in Kenya reach your site on a phone, often on a connection that is far from perfect, so a page that feels fine on your office laptop can feel painfully slow in the real world. Google measures this experience with three numbers called Core Web Vitals.
This guide explains what those numbers mean, how to test your own site for free, and the practical fixes that make WordPress and WooCommerce websites load faster and feel smoother on mobile. The thresholds below were checked in October 2026 and follow Google guidance.
The short answer
- Core Web Vitals are three measurements of real visitor experience: how fast the main content loads (LCP), how quickly the page responds to taps and clicks (INP) and how stable the layout is while loading (CLS).
- To pass, LCP should be 2.5 seconds or less, INP 200 milliseconds or less and CLS 0.1 or less, for at least 75 percent of visits.
- Most failures on WordPress sites come from oversized images, slow hosting, too many plugins and heavy third-party scripts, not from anything mysterious.
- Test on mobile, fix the biggest problem first and check the results in Search Console after a few weeks.
What Core Web Vitals are and why they matter
Core Web Vitals are a small set of metrics Google uses to judge the real experience of visiting a page. They come from real visitors using Chrome, not from a single test on your computer, which is why a page can look fine to you and still fail.
| Metric | What it measures | Good | Needs improvement | Poor |
|---|---|---|---|---|
| LCP (Largest Contentful Paint) | How long the main content, usually the top image or headline, takes to appear | 2.5 seconds or less | 2.5 to 4 seconds | Over 4 seconds |
| INP (Interaction to Next Paint) | How quickly the page reacts when someone taps, clicks or types | 200 milliseconds or less | 200 to 500 milliseconds | Over 500 milliseconds |
| CLS (Cumulative Layout Shift) | How much the layout jumps around while the page loads | 0.1 or less | 0.1 to 0.25 | Over 0.25 |
INP replaced the older First Input Delay metric in March 2024 and is stricter, because it looks at every interaction during a visit rather than only the first one. Google evaluates the 75th percentile of real visits, so a few fast visits cannot hide a slow majority.
Core Web Vitals are a ranking signal, but not the strongest one. A fast page with weak content will not outrank a slower page that answers the question better. Speed matters most as a tiebreaker and as a way to keep visitors who would otherwise leave. It also supports your wider SEO work.
How to check your own website
You do not need paid tools to find out where you stand. Two free Google tools give you almost everything.
- PageSpeed Insights. Enter your page address and read the mobile results first. The top section shows field data from real visitors when enough exists, and the section below shows a lab test with specific suggestions.
- Search Console. The Core Web Vitals report groups your pages into good, needs improvement and poor, separately for mobile and desktop, so you can see which type of page has a problem.
Lab results and field results can disagree. The lab test is a single controlled run and is good for checking a fix straight away. Field data reflects real visitors over a rolling 28 day period and is the number that counts for Google.
How to fix a slow LCP
LCP is usually the first problem to solve because it is the one visitors feel most. The main content is slow for one of four reasons: the server is slow to respond, the image is too big, the browser finds the image too late, or something blocks the page from drawing.
- Compress and resize images. Photos straight from a phone or camera are often several megabytes. Resize them to the size they are displayed at and use WebP, which keeps quality at a much smaller file size.
- Do not lazy load the top image. Lazy loading is excellent for images lower down the page, but the main image at the top should load immediately.
- Replace heavy sliders. Full-width sliders load several large images and scripts before showing anything. A single well-sized hero image usually loads far faster.
- Use caching. A caching setup serves a ready-made page instead of building it on every visit, which cuts server response time sharply.
- Choose better hosting. If the server itself takes a long time to answer, no amount of image tuning will rescue the result. Our hosting and maintenance cost guide explains what to look for.
How to fix a poor INP
INP problems almost always come from JavaScript. When a phone is busy running scripts, it cannot respond to a tap, and the page feels frozen. The fix is to give the browser less to do.
- Audit your plugins. Every plugin that adds scripts to every page costs speed. Remove any you do not actively use.
- Limit third-party scripts. Chat widgets, tracking pixels, review badges and social feeds each add code from another company. Keep the ones that earn their place and load them after the main content.
- Be careful with page builder add-ons. Stacking several add-on packs on top of a page builder loads a lot of code that the page may never use.
- Keep menus and filters simple. Complex mega menus and product filters that run heavy scripts on each tap are common causes of a slow response.
How to fix layout shift (CLS)
Layout shift is the annoying jump that makes you tap the wrong button because the page moved at the last moment. It is often the cheapest metric to fix because the causes are in the page structure.
- Set image dimensions. Give every image a width and height so the browser reserves space before it loads.
- Reserve room for banners and embeds. Cookie notices, promotional bars, maps and videos should sit in a space that is held open, not pushed in after the page has drawn.
- Load fonts sensibly. Use fonts that swap in smoothly and avoid loading many weights you do not use.
- Avoid inserting content above existing content. New elements should appear below what the visitor is already reading.
Common causes on WordPress and WooCommerce sites
Most slow Kenyan business sites share the same handful of problems. A well-built WordPress site avoids them from the start, and an online store needs extra care because product images, payment scripts and cart features add weight.
- A heavy multipurpose theme that loads features the site never uses.
- Large unoptimized photos and product images.
- Too many plugins, especially several that overlap in what they do.
- Sliders, animations and background videos on the home page.
- Cheap or overloaded shared hosting with slow server response.
- Several chat, analytics and social scripts all loading at once.
A practical order to fix things
- Run PageSpeed Insights on your home page and your most important service or product page, on mobile.
- Fix images first: resize, compress and convert to WebP.
- Set up page caching and check your hosting response time.
- Remove unused plugins and delay non-essential third-party scripts.
- Fix layout shifts by setting image sizes and reserving space for banners.
- Re-test, then check the Search Console report again after several weeks.
When to get professional help
Many image and plugin fixes are safe to do yourself. If your theme is heavy, your scores stay poor after the basics, or you run a store where mistakes could break checkout, it is worth bringing in a developer. Our Speed and Core Web Vitals service audits the site, fixes the biggest causes first and measures the result, and it sits within our wider web development work.
Frequently asked questions
What is a good Core Web Vitals score?
A page passes when at least 75 percent of real visits have a Largest Contentful Paint of 2.5 seconds or less, an Interaction to Next Paint of 200 milliseconds or less and a Cumulative Layout Shift of 0.1 or less. All three must be good for the page to pass.
Do Core Web Vitals affect Google rankings?
Yes, they are part of Google page experience signals, but they are one signal among many. Relevant, helpful content still matters most. Fast pages help most when competing pages are similar in quality, and they also improve how many visitors stay and buy.
Why is my website fast on my laptop but slow on phones?
Laptops have faster processors and usually better connections. Phones have less processing power and often weaker networks, so heavy images and scripts hurt more. Google uses the mobile version of your site, so always test on mobile first.
How long until my improvements show in Search Console?
Search Console uses real visitor data collected over a rolling 28 day period, so improvements can take several weeks to show fully. PageSpeed Insights lab results update immediately, which makes them useful for checking a fix while you wait.
Can a plugin fix my Core Web Vitals on its own?
A caching or optimization plugin can help, mainly with load time, but it cannot fix a heavy theme, oversized images or too many third-party scripts. Lasting results usually come from removing weight first and then tuning what remains.