Test the Site on the Right Tools

I always start with:

PageSpeed Insights (Core Web Vitals)

GTmetrix (waterfall analysis)

WebPageTest (advanced metrics)

I’m looking for issues like:

Slow TTFB

Large image payload

Render-blocking JS

Layout shifts

If images are the problem, I send clients here:
👉 The Complete Image Optimization Guide for 2025
(Internal link: Week 2 / Post #1)

Check Hosting & Server Response

A good site on bad hosting will still be slow.

I check:

PHP version

TTFB

CPU usage

Memory allocation

CDN usage

If hosting is weak, I recommend upgrading:
👉 The 2025 WordPress Hosting Guide
(Week 1 internal link)

Audit Plugins and Builder Add-ons

This is where most problems hide.

I look for:

Duplicate functionality

Unnecessary Elementor or Divi add-ons

Heavy third-party integrations

Plugins last updated 1+ year ago

If Elementor is bloated, this helps:
👉 The Real Reason Your Elementor Site Loads Slowly
(Week 3 internal link)

Analyze Theme & Builder Output

I check for:

Heavy DOM structure

Excessive nesting

Unused CSS

Unoptimized templates

If the builder is part of the problem, I compare alternatives:
👉 Bricks vs. Oxygen vs. Gutenberg: Which Is Fastest in 2025?
(Week 3 internal link)

Inspect Images & Media Library

I look at:

File sizes

Dimensions

Formats (WebP, PNG, JPEG)

Unused media

Most sites have 3–10MB hero banners slowing down LCP.

Check Scripts & CSS Blocking Rendering

This includes:

JS libraries

Font files

External scripts

Third-party embeds

If INP, CLS, or LCP are failing, I fix them using this framework:
👉 Core Web Vitals: How I Fix INP, CLS, and LCP for Clients
(Week 2 internal link)

Test Caching & CDN

I check:

Cloudflare / BunnyCDN

Page caching

Browser caching

Object caching

Gzip/Brotli compression

If caching isn’t configured, here’s the guide:
👉 The Ultimate Caching Setup for WordPress
(Week 2 internal link)

Final Thoughts

A speed audit isn’t guesswork—it’s a repeatable system.
By following this checklist, you can diagnose 95% of website performance issues in under an hour.

Next step: see what I always remove from slow sites:
👉 10 Things I Remove from Every New Client Website
(Internal link to Post #2)