How to Test Your Website Speed (Free Tools)

Sam Hemburyยท27 December 2024ยท7 min readยทBeginner

A practical guide to testing your website's performance using free tools. Learn how to use PageSpeed Insights, GTmetrix, and more to identify what's slowing your site down.

Key Takeaways

  • 1PageSpeed Insights is Google's official tool and the most important one to use
  • 2Always test your mobile score - that's what most visitors experience
  • 3Test multiple pages, not just your homepage
  • 4Real-world data (field data) matters more than lab tests
  • 5Focus on fixing issues that have the biggest impact first

Want to know if your website is fast enough? Here's how to test it properly - using free tools that give you actionable information.

The Best Free Speed Testing Tools

1. Google PageSpeed Insights (Most Important)

URL: pagespeed.web.dev

This is Google's own tool, and the one that matters most for SEO. It shows you exactly what Google sees when it evaluates your site.

What it tells you:

  • Your Core Web Vitals scores (LCP, INP, CLS)
  • A performance score from 0-100
  • Specific issues to fix
  • The estimated impact of each fix

Key tip: Look at the "Field Data" section if available - this shows real performance data from actual Chrome users. "Lab Data" is a simulation; Field Data is reality.

๐Ÿ”
Field Data beats Lab Data every time
PageSpeed Insights shows two types of results. "Field Data" is from real Chrome users visiting your site โ€” that's what Google actually uses for rankings. "Lab Data" is a simulation. If both are available, focus on Field Data.

2. GTmetrix

URL: gtmetrix.com

GTmetrix provides more detailed waterfall charts showing exactly what loads and when. Useful for diagnosing specific issues.

What it tells you:

  • Performance scores
  • Detailed loading waterfall
  • Largest Contentful Paint filmstrip
  • Structure and recommendations

Key tip: Create a free account to test from UK servers (default is Canada, which adds latency for UK-based sites).

3. WebPageTest

URL: webpagetest.org

The most detailed tool, used by developers. Overkill for most business owners but useful if you need deep analysis.

What it tells you:

  • Frame-by-frame loading filmstrip
  • Advanced metrics
  • Multi-step testing
  • Connection throttling options

4. Chrome DevTools (Built into Chrome)

Right-click any page, select "Inspect", then click the "Lighthouse" tab. Run an audit directly in your browser.

What it tells you:

  • Performance score
  • Accessibility issues
  • Best practices
  • SEO basics

Key tip: Use an incognito window to avoid browser extensions affecting results.

How to Test Properly

Step 1: Test Mobile First

Most local searches happen on mobile. Google uses mobile performance for rankings. Always check your mobile score before desktop.

In PageSpeed Insights, mobile is shown by default. The scores are typically lower than desktop - that's normal.

Step 2: Test Multiple Pages

Don't just test your homepage. Check:

  • Homepage - Often the fastest (most optimised)
  • Service pages - May have more images and content
  • Blog posts - Often image-heavy
  • Contact page - Usually fast (simple content)

If your homepage scores 85 but your service pages score 45, you have a problem visitors will experience.

Step 3: Test From the Right Location

If your business serves UK customers, test from UK servers. GTmetrix lets you choose test location. PageSpeed Insights uses Google's global infrastructure but Field Data reflects your actual visitors.

Step 4: Test Multiple Times

Scores can vary slightly between tests due to server load and network conditions. Run 2-3 tests and look for consistent patterns rather than obsessing over a single score.

๐Ÿ“ฑ
Your mobile score is the one that matters
Google uses mobile performance for rankings, and most local searches happen on phones. Don't be fooled by a good desktop score โ€” the mobile number is what your customers actually experience.
Typical desktop score: 85โ€“95 Same site on mobile: 50โ€“70 Google ranks based on mobile

Understanding Your Scores

The Performance Score (0-100)

Score Rating What It Means
90-100 Good (Green) Your site is fast. Well done.
50-89 Needs Improvement (Orange) Room for improvement. You're losing some visitors.
0-49 Poor (Red) This is actively hurting your business. Take action.

What's Realistic?

  • Custom-built sites: Often score 90+
  • Well-optimised WordPress: Typically 70-90
  • Average WordPress: Usually 50-70
  • Wix/Squarespace: Typically 50-75 on mobile
  • Unoptimised sites: Often below 50

Don't compare yourself to Google's homepage. Compare yourself to your competitors.

Reading the Diagnostics

PageSpeed Insights shows opportunities and diagnostics. Here's how to prioritise:

High Impact (Fix First)

  • Serve images in next-gen formats - Switch to WebP
  • Properly size images - Don't load 4000px images for 400px spaces
  • Eliminate render-blocking resources - Scripts blocking the page from loading
  • Reduce unused JavaScript - Code that loads but isn't used

Medium Impact

  • Enable text compression - Server configuration
  • Preconnect to required origins - Technical optimisation
  • Serve static assets with efficient cache policy - Server configuration

Lower Impact (But Still Helpful)

  • Avoid multiple page redirects - Each redirect adds delay
  • Minify CSS/JavaScript - Remove unnecessary characters from code
  • Avoid enormous network payloads - General page weight

๐ŸŽฏ
Images and render-blocking scripts โ€” fix those two first
PageSpeed Insights shows estimated savings for each issue. In practice, the top two culprits are almost always the same: oversized images and render-blocking resources. Fix those before touching anything else.
High impact: Image optimisation, render-blocking CSS/JS, server response time
Medium impact: Caching, unused code removal, font loading
Lower impact: Minor layout shifts, accessibility tweaks, meta optimisation

The Testing Workflow

Here's a practical approach to speed testing:

Initial Baseline

  1. Test your homepage on PageSpeed Insights
  2. Note your mobile Core Web Vitals (LCP, INP, CLS)
  3. Screenshot or save the report
  4. Test 2-3 other important pages

After Making Changes

  1. Wait for changes to deploy (and clear any caching)
  2. Run the same tests
  3. Compare before/after scores
  4. Check if Field Data updates (this takes weeks as Google collects new data)

Monthly Check

  1. Quick test of key pages
  2. Note any score drops
  3. Investigate if scores have worsened significantly

Common Mistakes When Testing

Testing Only the Homepage

Your homepage is often your fastest page because it gets the most attention. Test the pages visitors actually use.

Testing on Fast WiFi

PageSpeed Insights simulates slower connections automatically. But when you manually browse your site, do it on your phone with mobile data to feel what visitors experience.

Obsessing Over Perfect Scores

The difference between 85 and 100 is marginal. Focus on getting out of the red, not achieving perfection.

Ignoring Mobile

Desktop scores are almost always higher. Mobile is what matters for most local businesses.

Testing Once and Forgetting

Speed degrades over time as you add content, plugins, and features. Make testing a regular habit.

What to Do With Your Results

Once you've tested, you'll likely find issues to address. Here's how to proceed:

Easy Wins (Do Yourself)

  • Compress images before uploading
  • Remove plugins/apps you're not using
  • Reduce the number of fonts you're loading

Moderate Difficulty

  • Switch to a faster hosting provider
  • Enable caching (if your platform supports it)
  • Optimise your largest images

Requires Professional Help

  • Code optimisation and minification
  • Server configuration (CDN, caching rules)
  • Fixing render-blocking resources
  • Core architectural issues

The Bottom Line

Regular speed testing is essential for maintaining a healthy website. Use Google PageSpeed Insights as your primary tool, always check mobile scores, and test more than just your homepage.

Don't chase perfect scores - focus on fixing the biggest issues first and getting all metrics into the green. And remember: real improvement matters more than impressive numbers.

Test your site now at pagespeed.web.dev and see where you stand.

Frequently Asked Questions

Which speed test tool should I use?
Start with Google's PageSpeed Insights - it's free, uses Google's actual data, and is the most relevant for SEO. GTmetrix is useful for more detailed analysis. Don't obsess over using multiple tools; they often give different scores because they measure different things.
Why do different tools give different scores?
Each tool tests from different locations, simulates different devices, and weighs factors differently. PageSpeed Insights uses a mid-range phone on 4G. GTmetrix can use various configurations. Focus on trends and major issues rather than exact numbers.
How often should I test my website speed?
Test monthly as a baseline. Also test after making significant changes - adding new plugins, uploading lots of images, or changing hosts. Speed can degrade gradually without you noticing.
My homepage is fast but other pages are slow - is that a problem?
Yes. Visitors don't always enter through your homepage. If your service pages or blog posts are slow, that affects user experience and rankings for those pages. Test your most important pages individually.

Sources & References

Tagged with:

Speed TestingPageSpeed InsightsGTmetrixPerformance Tools
Share this article

Need Help Implementing This?

Pink Frog Studio builds fast, secure websites that actually get found. Let's chat about your project.