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How to Run a Speed Test

Performance work starts with a clean measurement.

This page gives you a repeatable testing routine you can use on any WordPress site.


Don’t test the homepage only.

Pick one real page that represents your site:

  • a blog post
  • a product page (WooCommerce)
  • a landing page with sliders/forms
  • the heaviest page users actually visit

If you test random pages every time, your results won’t be comparable.


Use one “quick” tool and one “deep” tool:

  • PageSpeed Insights (mobile)
  • WebPageTest or DebugBear (waterfall)

The goal is not “more tools”.
The goal is consistency.


Performance varies. Networks vary.

Run 3 tests and look for patterns.

Mobile is harder:

  • slower CPU
  • slower network
  • more sensitive to JavaScript

If you can make mobile fast, desktop will follow.

If you’re testing manually:

  • Incognito window
  • no extensions
  • no logged-in admin bar

Create a simple note and record:

  • URL tested
  • Date/time
  • Tool used
  • Mobile score (optional)
  • TTFB
  • LCP
  • CLS
  • INP
  • Notes about what stands out (big images, long server response, JS blocking)

You want a “before” snapshot you can compare later.


If you see a bad score, resist the urge to fix things immediately.

First, you want to understand:

  • Is it a server issue (TTFB)?
  • Is it a rendering issue (LCP)?
  • Is it layout shifting (CLS)?
  • Is it interaction delay (INP)?

That’s the Diagnose step.


  1. Learn what the key metrics actually mean: TTFB, LCP, CLS, INP
  2. Then move to: Waterfall Analysis to identify the real bottleneck