Site Speed and Core Web Vitals — Why It Matters and How to Improve It

A one-second delay = a 7% drop in conversion. This isn't a lab number — it has been reproduced for years in online retail. And since 2021, Google officially factors speed into rankings: Core Web Vitals.

The three metrics you should know

LCP — Largest Contentful Paint

When the user clicks, how long until the biggest element (usually the hero image or headline) appears?

• Good: under 2.5 seconds
• Bad: over 4 seconds

CLS — Cumulative Layout Shift

Ever clicked a button and the page "jumped" so you clicked something else? That's CLS — an experience that frustrates users and displeases Google.

• Good: under 0.1

INP — Interaction to Next Paint

When the user taps a button, how fast does the page respond?

• Good: under 200ms

Why these numbers are vital for your business

1. SEO ranking: Google uses these metrics in search results
2. Conversion: mobile users on weak connections don't wait
3. Ad efficiency: a slow landing page burns ad money in front of waiting eyes
4. Brand credibility: a fast site feels professional; a slow one feels hopeless

Measurement tools — free and official

• PageSpeed Insights — mobile/desktop scores + details
• Chrome UX Report / Search Console — your real users' data
• Lighthouse (in Chrome DevTools) — deep technical analysis

Important: PageSpeed lab data is simulated; the "Field Data" column (real user data) is what Google judges.

8 real improvements with the biggest impact

1. Optimize images (the biggest culprit)

• WebP/AVIF instead of PNG/JPG — 30-70% smaller
• loading="lazy" for below-the-fold images
• Set real dimensions in HTML (width/height) — helps CLS too

2. Load fonts correctly

• font-display: swap — text shows instantly with a fallback font
• Only the weights you need (not 7!)
• Preload the main font: rel="preload"

3. Reduce and defer CSS/JS

• Inline critical CSS, defer the rest
• Remove unused CSS/JS (especially from heavy templates)
• Non-critical JS with defer

4. CDN and caching

• Browser caching for static files (1 year!)
• CDN to bring servers closer to users

5. Responsive server (TTFB)

• Weak shared hosting = all other efforts wasted
• Updated PHP / HTTP/2 / adequately resourced hosting

6. Rein in third-party scripts

Every chat script, analytics pixel, ad tag = extra weight. Keep the essentials; remove or delay the rest.

7. Pre-render audits

Plugins that build heavy DOM (sliders, lots of animation) — review and remove.

8. Set a performance budget

An organizational rule: no new page should exceed a set limit (say 1MB) — checked before publishing.

Where to start — 3 simple steps

1. Measure all pages in PageSpeed — start with your 10 most-visited
2. Fix the biggest culprit — usually images and fonts
3. Re-measure and watch Search Console — check improvements monthly

Wrap-up

Speed is both SEO and sales. If your current site has a poor mobile score, you're probably losing customers and money every month.

Sites built by Kurdnet come with a performance budget from day one — get a free site review.