A slow WordPress site costs you twice: visitors leave before the page appears, and search engines treat poor page experience as a weaker result. Most slow sites are not slow for one big reason. They are slow because of ten small ones. This checklist is the order I follow when I audit a site.
Key takeaways
- Measure first, using real-user data, not only a lab score.
- Fix the server and caching before you touch any image or script.
- Remove weight (plugins, scripts, fonts) before you add tools to hide it.
What "passing" means
Google reports three Core Web Vitals, judged at the 75th percentile of real visits:
| Metric | What it measures | Good |
|---|---|---|
| LCP | How fast the main content appears | 2.5 s or less |
| INP | How fast the page reacts to taps and clicks | 200 ms or less |
| CLS | How much the layout jumps | 0.1 or less |
Check the real numbers in PageSpeed Insights (the "field data" block) and the Core Web Vitals report in Search Console. A perfect lab score on your own fast laptop proves very little.
1. Fix the foundation: hosting and caching
If the server takes a long time to answer (high TTFB), nothing else can fully save you.
- Use a host with current PHP, enough memory and SSD storage.
- Turn on full-page caching so most visits never run PHP at all.
- Add object caching (Redis or Memcached) for logged-in users, WooCommerce and dynamic pages.
- Put a CDN in front, so images and files come from a server near the visitor.
2. Make the biggest element fast (LCP)
The LCP element is usually the hero image or a large heading.
- Serve modern formats (WebP or AVIF) at the size actually shown, with
srcset. - Never lazy-load the LCP image. Give it
fetchpriority="high"instead. - Preload the one font you need and use
font-display: swap. - Avoid sliders in the first screen. They are slow and rarely help.
3. Cut JavaScript and CSS (INP)
- Audit plugins with Query Monitor. Delete the ones you do not truly use.
- Load scripts only on the pages that need them (for example, a form plugin only on the contact page).
- Defer non-critical JavaScript and delay chat widgets, heatmaps and tag managers until the first interaction.
- Replace heavy page-builder add-ons with a few lines of CSS where possible.
4. Stop the layout jumping (CLS)
- Always set
widthandheighton images and video. - Reserve space for ads, banners and cookie notices.
- Do not inject content above what the visitor is already reading.
5. Clean the database and keep it clean
Old revisions, expired transients and abandoned plugin tables slow queries. Clean them, limit post revisions, and schedule it.
Common mistakes
- Installing three optimization plugins that fight each other.
- Chasing a 100 score instead of real-user metrics.
- Compressing images but leaving a 2 MB hero background video.
- Optimizing only the home page. Check your top landing pages too.
When to ask for help
If the site is still slow after caching, image work and a plugin audit, the cause is usually theme code, a heavy builder layout or a slow database query. That is where a developer pays for themselves. If you want an audit with a clear, prioritized list and a fixed price, send me the URL and I will tell you what I would change first.
