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Blog / Website Speed

Website Speed Optimization: A Practical Core Web Vitals Guide

This checklist comes from real optimization work: the same steps that turned our own PageSpeed green — step by step, with no extra theory.

1. Images: The Biggest Chunk

In our experience, converting multi-megabyte PNG screenshots to optimized JPEG cut size by about 97%. The rules: real display dimensions (no larger), modern formats (WebP for photos, JPEG for screenshots), loading="lazy" below the fold, and explicit dimensions to prevent layout shift.

2. Fonts: The Silent LCP Killer

A Google font means one render-blocking request plus an external connection chain. The fix: self-hosting with font-display: swap. Users first see text in a system font, then the main font swaps in — LCP improves dramatically.

3. JavaScript: Only the Essentials

A 110 KB animation library on a mobile device that never sees the animation is waste. The pattern: conditional loading based on viewport width and prefers-reduced-motion, with a simple fallback. Non-critical scripts always get defer.

4. Caching and Server

Images and fonts: one-year immutable cache. CSS/JS: one month + automatic versioning on file change. HTML: no cache. This combination means fast repeat visits while never serving a stale version. Technical details in technical SEO services.

5. Measuring Correctly

Lab scores differ from real-user (field) data; base decisions on the 28-day Search Console span and PageSpeed — not a single test. If your mobile score is under 90, start with a free consultation.

Next Step

Speed cannot be guessed — it must be measured and improved step by step. See the portfolio and the pricing calculator.