Website Speed Test: How to Check & Improve Performance

How to Test Your Website Speed

Website speed is a crucial ranking factor and directly impacts user experience. Slow sites have higher bounce rates and lower conversions. This guide explains how to test your speed and improve it.

Why Website Speed Matters

For SEO

• Core Web Vitals are Google ranking factors
• Faster sites get crawled more efficiently
• Speed affects mobile rankings significantly

For Users

• 53% of mobile users abandon sites that take >3 seconds
• Every 1-second delay reduces conversions by 7%
• Slow sites create poor user experiences

For Business

• Amazon found every 100ms delay cost 1% in sales
• Faster sites have higher conversion rates
• Speed builds trust and credibility

How to Test Your Website Speed

Using Google PageSpeed Insights

1. Visit pagespeed.web.dev
2. Enter your URL
3. Wait for analysis
4. Review scores for mobile and desktop

PageSpeed Insights provides:

• Performance score (0-100)
• Core Web Vitals assessment
• Specific improvement opportunities
• Diagnostic information

Using Auditora Speed Test

1. Go to Auditora's Core Web Vitals tool
2. Enter your website URL
3. Get performance analysis
4. View prioritized recommendations

Using WebPageTest

1. Visit webpagetest.org
2. Enter URL and select test location
3. Run test
4. Review waterfall and metrics

Understanding Core Web Vitals

Core Web Vitals are the metrics Google uses to measure user experience:

LCP (Largest Contentful Paint)

What it measures: Loading performance - how long until the main content is visible.

Targets:

• Good: ≤ 2.5 seconds
• Needs Improvement: 2.5 - 4 seconds
• Poor: > 4 seconds

Common causes of slow LCP:

• Large images above the fold
• Slow server response time
• Render-blocking JavaScript/CSS
• Slow resource load times

INP (Interaction to Next Paint)

What it measures: Interactivity - how quickly the page responds to user input.

Targets:

• Good: ≤ 200ms
• Needs Improvement: 200 - 500ms
• Poor: > 500ms

Common causes of slow INP:

• Long JavaScript tasks
• Large DOM size
• Heavy third-party scripts
• Main thread blocking

CLS (Cumulative Layout Shift)

What it measures: Visual stability - how much the page layout shifts during load.

Targets:

• Good: ≤ 0.1
• Needs Improvement: 0.1 - 0.25
• Poor: > 0.25

Common causes of high CLS:

• Images without dimensions
• Ads/embeds without reserved space
• Web fonts causing FOUT/FOIT
• Dynamically injected content

How to Improve Website Speed

Quick Wins

1. Optimize Images

   • Compress images (TinyPNG, Squoosh)
   • Use modern formats (WebP, AVIF)
   • Specify dimensions in HTML
   • Lazy load below-fold images

2. Enable Compression

   • Enable Gzip or Brotli compression
   • Reduces file sizes by 70%+

3. Leverage Browser Caching

   • Set appropriate cache headers
   • Cache static assets for 1 year

4. Minimize CSS/JavaScript

   • Remove unused code
   • Minify files
   • Defer non-critical JavaScript

Advanced Optimizations

1. Use a CDN

   • Serves content from nearest location
   • Reduces latency significantly
   • Popular options: Cloudflare, Fastly

2. Optimize Server Response

   • Upgrade hosting if needed
   • Enable server-side caching
   • Use a fast DNS provider

3. Reduce Third-Party Scripts

   • Audit all third-party code
   • Remove unnecessary trackers
   • Load scripts asynchronously

4. Optimize Web Fonts

   • Use font-display: swap
   • Subset fonts to needed characters
   • Preload critical fonts

Speed Optimization Checklist

Images

• Compressed to optimal size
• Using WebP format
• Dimensions specified
• Lazy loading implemented
• Responsive images configured

Code

• CSS minified
• JavaScript minified
• Unused code removed
• Critical CSS inlined
• Non-critical JS deferred

Server

• Compression enabled
• Caching configured
• CDN in use
• Fast hosting provider
• HTTP/2 or HTTP/3 enabled

Third-Party

• Scripts audited
• Loaded asynchronously
• Unnecessary scripts removed
• Tag manager optimized

Testing Schedule

After Major Changes

• Test immediately after launches
• Compare before/after metrics

Weekly

• Quick PageSpeed check on key pages
• Monitor Core Web Vitals

Monthly

• Full site speed audit
• Review trends in Search Console

Tools Summary

Free Tools

• Google PageSpeed Insights
• GTmetrix
• WebPageTest
• Auditora Speed Test

Paid Tools

• Lighthouse CI (automated testing)
• SpeedCurve (performance monitoring)
• New Relic (detailed analysis)

Conclusion

Website speed is no longer optional—it's a competitive necessity. Use the tools and techniques in this guide to test your current performance and make targeted improvements.

Focus on Core Web Vitals first, then work through the optimization checklist. Even small improvements can significantly impact your rankings and conversions.