Website Speed Test

Analyze your website's performance with Core Web Vitals, actionable code snippets, and detailed optimization recommendations.

HTTPS://

github.com

9/9/2025, 7:33:36 am UTC

Core Web Vitals Needs Work

LCP

1,530ms

Good

FID

2ms

Good (est)

CLS

1.1

Poor (est)

FCP

16ms

Good

TTFB

93ms

Good

What These Metrics Mean for Your Business
LCP (Largest Contentful Paint):

Users see content quickly - minimal bounce risk

FID (First Input Delay):

Interactive elements respond immediately

CLS (Cumulative Layout Shift):

Unstable layout - users may click wrong elements

Performance Overview

55

Performance Score

Needs Work

Page Load Time

1,530ms

Complete page load

Total Size

10.03 MB

HTTP Requests

96

Copy-Paste Code Fixes

Preload Critical CSS
High Impact

Preload critical stylesheets to prevent render blocking

200-500ms faster First Contentful Paint

HTML - Add to <head> section
<!-- Preload critical CSS for faster rendering -->
<link rel="preload" href="https://github.githubassets.com/assets/primer-primitives-dc7ca6859caf.css" as="style" onload="this.onload=null;this.rel='stylesheet'">
<noscript><link rel="stylesheet" href="https://github.githubassets.com/assets/primer-primitives-dc7ca6859caf.css"></noscript>
Async Load Non-Critical CSS
Medium Impact

Load large CSS files asynchronously to prevent render blocking

100-300ms faster page rendering

HTML - Add before closing </body> tag
<!-- Load non-critical CSS asynchronously -->
<script>
function loadCSS(href) {
  var link = document.createElement('link');
  link.rel = 'stylesheet';
  link.href = href;
  document.head.appendChild(link);
}

loadCSS('https://github.githubassets.com/assets/light-6448649c7147.css');
loadCSS('https://github.githubassets.com/assets/light_high_contrast-42fc7e3b06b7.css');
loadCSS('https://github.githubassets.com/assets/dark-d17b946fc2c5.css');
loadCSS('https://github.githubassets.com/assets/dark_high_contrast-1b924088c83a.css');
loadCSS('https://github.githubassets.com/assets/primer-f96b923db733.css');
loadCSS('https://github.githubassets.com/assets/global-2744ca59d025.css');
loadCSS('https://github.githubassets.com/assets/github-f7128b22e253.css');
loadCSS('https://github.githubassets.com/assets/site-36e5e1b0bd56.css');
loadCSS('https://github.githubassets.com/assets/landing-pages-e72ec641ec1c.css');
loadCSS('https://github.githubassets.com/assets/home-81413a57f179.css');
loadCSS('https://github.githubassets.com/assets/primer-react.d0c7fff6074fe65697c3.module.css');
loadCSS('https://github.githubassets.com/assets/landing-pages.3f5bf4b40ca8a04b8f45.module.css');
</script>
Optimize Images with Modern Formats
High Impact

Use WebP format and lazy loading for large images

30-70% smaller image file sizes

HTML - Replace large <img> tags
<!-- Responsive images with modern formats -->
<picture>
  <source srcset="images/accordion-1-ce487d44c0bf.webp" type="image/webp">
  <source srcset="images/accordion-1-ce487d44c0bf.jpg" type="image/jpeg">
  <img src="https://images.ctfassets.net/8aevphvgewt8/1Dt1ncaR6ZM4dQvknFzfBI/e5c2092be5bd53881622eced4fd37564/accordion-1-ce487d44c0bf.webp" alt="Description" loading="lazy" 
       width="800" height="600">
</picture>

<picture>
  <source srcset="images/accordion-2-730955545f07.webp" type="image/webp">
  <source srcset="images/accordion-2-730955545f07.jpg" type="image/jpeg">
  <img src="https://images.ctfassets.net/8aevphvgewt8/1uXZYDy7dMcH9QwxuAU06F/1cb167cc60d725b8cf7089faf9a4ed06/accordion-2-730955545f07.webp" alt="Description" loading="lazy" 
       width="800" height="600">
</picture>

<picture>
  <source srcset="images/accordion-3-52ca331d22ea.webp" type="image/webp">
  <source srcset="images/accordion-3-52ca331d22ea.jpg" type="image/jpeg">
  <img src="https://images.ctfassets.net/8aevphvgewt8/3xzVZaJhqo3B62R8NeHjX2/e37c81e4f26e9dac2aff1f23a0243087/accordion-3-52ca331d22ea.webp" alt="Description" loading="lazy" 
       width="800" height="600">
</picture>

<!-- CSS for responsive behavior -->
<style>
img {
  max-width: 100%;
  height: auto;
}
</style>
Add Lazy Loading to Images
Medium Impact

Load images only when they come into view

Faster initial page load, reduced bandwidth

HTML - Add loading="lazy" to img tags, script before </body>
<!-- Add lazy loading to images below the fold -->
<img src="image.jpg" alt="Description" loading="lazy" width="400" height="300">

<!-- For better browser support, use this polyfill -->
<script>
if ('loading' in HTMLImageElement.prototype) {
  // Native lazy loading supported
} else {
  // Fallback for older browsers
  var images = document.querySelectorAll('img[loading="lazy"]');
  var imageObserver = new IntersectionObserver(function(entries, observer) {
    entries.forEach(function(entry) {
      if (entry.isIntersecting) {
        var image = entry.target;
        image.src = image.dataset.src;
        image.classList.remove('lazy');
        imageObserver.unobserve(image);
      }
    });
  });
  images.forEach(function(img) { imageObserver.observe(img); });
}
</script>
Enable Server Compression
High Impact

Compress text files to reduce transfer size by 60-80%

60-80% smaller file sizes for text-based resources

APACHE - Add to .htaccess or server configuration
# Add to your .htaccess file for Apache
<IfModule mod_deflate.c>
    # Compress HTML, CSS, JavaScript, Text, XML and fonts
    AddOutputFilterByType DEFLATE application/javascript
    AddOutputFilterByType DEFLATE application/rss+xml
    AddOutputFilterByType DEFLATE application/vnd.ms-fontobject
    AddOutputFilterByType DEFLATE application/x-font
    AddOutputFilterByType DEFLATE application/x-font-opentype
    AddOutputFilterByType DEFLATE application/x-font-otf
    AddOutputFilterByType DEFLATE application/x-font-truetype
    AddOutputFilterByType DEFLATE application/x-font-ttf
    AddOutputFilterByType DEFLATE application/x-javascript
    AddOutputFilterByType DEFLATE application/xhtml+xml
    AddOutputFilterByType DEFLATE application/xml
    AddOutputFilterByType DEFLATE font/opentype
    AddOutputFilterByType DEFLATE font/otf
    AddOutputFilterByType DEFLATE font/ttf
    AddOutputFilterByType DEFLATE image/svg+xml
    AddOutputFilterByType DEFLATE image/x-icon
    AddOutputFilterByType DEFLATE text/css
    AddOutputFilterByType DEFLATE text/html
    AddOutputFilterByType DEFLATE text/javascript
    AddOutputFilterByType DEFLATE text/plain
    AddOutputFilterByType DEFLATE text/xml
</IfModule>

# For Nginx, add to your server block:
# gzip on;
# gzip_vary on;
# gzip_min_length 1024;
# gzip_types text/plain text/css text/xml text/javascript application/x-javascript application/xml+rss application/javascript;

Technical Analysis

HTTP Version

HTTP/2

Modern protocol - faster loading

Compression

Gzip

Files compressed - saves bandwidth

Time to First Byte

93ms

Excellent response time

Render Blocking

13 resources

Consider async/defer loading

Resource Analysis with Timeline

Action Icons
🚫 Blocks rendering
🖼️ Optimize image
🔄 Convert format
Add lazy loading
📦 Minify/split
🐌 Slow loading
🌐 Third-party resource
Well optimized
Type Resource URL Size Timeline Actions
CSS
https://github.githubassets.com/assets/light-6448649c7147.css
77.4 KB
Started: 0ms after page load
Duration: 16ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/light_high_contrast-42fc7e3b06b7.css
77.96 KB
Started: 16ms after page load
Duration: 15ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/dark-d17b946fc2c5.css
77.3 KB
Started: 32ms after page load
Duration: 15ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/dark_high_contrast-1b924088c83a.css
77.83 KB
Started: 48ms after page load
Duration: 15ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/primer-primitives-dc7ca6859caf.css
10.47 KB
Started: 64ms after page load
Duration: 13ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/primer-f96b923db733.css
346.94 KB
Started: 77ms after page load
Duration: 16ms to complete
🚫 📦 Add async loading
CSS
https://github.githubassets.com/assets/global-2744ca59d025.css
292.1 KB
Started: 94ms after page load
Duration: 17ms to complete
🚫 📦 Add async loading
CSS
https://github.githubassets.com/assets/github-f7128b22e253.css
144.35 KB
Started: 111ms after page load
Duration: 15ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/site-36e5e1b0bd56.css
69.24 KB
Started: 127ms after page load
Duration: 14ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/landing-pages-e72ec641ec1c.css
670.75 KB
Started: 142ms after page load
Duration: 18ms to complete
🚫 📦 Add async loading
CSS
https://github.githubassets.com/assets/home-81413a57f179.css
42.15 KB
Started: 161ms after page load
Duration: 14ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/primer-react.d0c7fff6074fe65697c3.module.css
198.63 KB
Started: 176ms after page load
Duration: 14ms to complete
🚫 📦 Add async loading
CSS
https://github.githubassets.com/assets/landing-pages.3f5bf4b40ca8a04b8f45.module.css
29.3 KB
Started: 192ms after page load
Duration: 14ms to complete
🚫 Add async loading
CSS
https://github.githubassets.com/assets/primer-react.d0c7fff6074fe65697c3.module.css
198.63 KB
Started: 207ms after page load
Duration: 15ms to complete
📦 Minify/split
CSS
https://github.githubassets.com/assets/keyboard-shortcuts-dialog.2de9c7d6456a311fce49.module.css
1.72 KB
Started: 223ms after page load
Duration: 13ms to complete
Optimized
JS
https://github.githubassets.com/assets/high-contrast-cookie-f3788027bd8d.js
1.54 KB
Started: 237ms after page load
Duration: 13ms to complete
Optimized
JS
https://github.githubassets.com/assets/wp-runtime-4ed7f03a497d.js
90.7 KB
Started: 250ms after page load
Duration: 16ms to complete
Optimized
JS
https://github.githubassets.com/assets/vendors-node_modules_oddbird_popover-polyfill_dist_popover-fn_js-468bf7cab607.js
9.67 KB
Started: 266ms after page load
Duration: 14ms to complete
Optimized
JS
https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_stacktrace-parser_dist_s-1d3d52-25523f4ee061.js
14.77 KB
Started: 281ms after page load
Duration: 13ms to complete
Optimized
JS
https://github.githubassets.com/assets/packages_failbot_failbot_ts-7cdfcb8274ec.js
10.39 KB
Started: 295ms after page load
Duration: 14ms to complete
Optimized

Showing first 20 of 95 resources

Timeline Colors:
CSS
JavaScript
Images

Performance Issues

12 large render-blocking resources delay page display

Users see blank page longer

Severity: High

4 resources over 500KB found

Slow loading on mobile/poor connections

Severity: Medium

Optimization Recommendations

Optimize Large Images
Medium - Faster loading, less bandwidth

Category: Images

Compress 2 large images and consider WebP format