Every second of load time costs you readers — research has long shown that bounce rates climb steeply as pages slow, and Google bakes speed into rankings through Core Web Vitals. The good news: most slow websites are slow for the same five boring reasons, and most fixes are free. Here’s the practical guide, whether you run WordPress, a custom site, or an online store.
Meet the three metrics (in human language)
Google measures user experience through three numbers:
LCP — Largest Contentful Paint. How long until the main content (usually your hero image or headline) is visible. Target: under 2.5 seconds. This is “how fast does the page feel loaded.”
INP — Interaction to Next Paint. When a user taps or clicks, how quickly does the page respond? Target: under 200 milliseconds. INP replaced the older FID metric and it’s stricter — it measures responsiveness throughout the visit, not just the first click.
CLS — Cumulative Layout Shift. Does the page jump around while loading — the infamous “I tried to tap a button and an ad shoved it away” experience? Target: under 0.1.
First, measure — don’t guess
Run your site through PageSpeed Insights (free, from Google). Critically, look at the field data section — real visitor measurements — not just the lab score. A mediocre lab score with good field data means real users are fine. Use Search Console’s Core Web Vitals report to see which page groups fail across your whole site. Ten minutes of measurement prevents weeks of optimizing the wrong thing.
Fixing LCP (the usual suspect: images)
The overwhelming majority of LCP problems are one thing: a huge, unoptimized hero image. The fix stack, in order of impact:
- Compress and convert images to WebP/AVIF. A 3MB JPEG becomes a 150KB WebP with no visible difference. WordPress plugins and free tools like Squoosh automate this.
- Size images to their display size. Don’t serve a 4000px photo into a 800px slot.
- Lazy-load below-the-fold images — but never the hero. Lazy-loading your LCP image is a classic self-inflicted wound; the top image should load eagerly, everything below can wait.
- Use decent hosting and a CDN. Cheap overloaded hosting caps your speed no matter what else you do; a CDN (Cloudflare’s free tier is fine) serves files from near your visitors.
- Enable caching so repeat views are instant (any major WordPress cache plugin, or proper cache headers on custom sites).
Fixing INP (the usual suspect: JavaScript)
Slow interactions come from the browser choking on scripts. The biggest offenders on typical sites aren’t your code — they’re third-party scripts: excessive analytics, chat widgets, ad tags, and social embeds. Audit them honestly and delete what you don’t truly use; each one taxes every visitor. Then defer non-critical JavaScript so it loads after the content, and on WordPress, be ruthless about plugin count — each plugin is code someone else wrote running on your visitors’ phones.
Fixing CLS (the usual suspect: missing dimensions)
Layout shift has mercifully simple causes: images without width/height attributes (the browser can’t reserve space, so content jumps when they arrive — always set dimensions), ads and embeds without reserved containers (give them a fixed-size box), and web fonts swapping late (use font-display: swap and preload your main font).
The 80/20 checklist
If you do only five things: compress images to WebP, add a caching plugin or CDN, delete unused plugins/scripts, set image dimensions everywhere, and don’t lazy-load the hero. That list alone moves most failing sites to passing.
Keep perspective
Core Web Vitals are a ranking factor, not the ranking factor — brilliant content on a slightly slow site still beats thin content on a fast one. But speed compounds quietly: better rankings, lower bounce, higher conversions, happier readers on cheap phones and slow connections — which, worldwide, is most readers. Measure this week, fix the image problem you almost certainly have, and re-measure in a month. Your analytics will say thanks.