London Office 128 City Rd, EC1V 2NX UK

You’re looking to significantly improve your website’s speed, focusing on Largest Contentful Paint (LCP)

I. Understanding LCP and FCP

Before diving into solutions, it’s crucial to understand what these metrics represent:

II. General Principles for Website Speed Optimization

These principles underpin all specific optimizations:

  1. Prioritize Critical Path: Identify and load the essential resources (HTML, critical CSS, JavaScript for above-the-fold content) as quickly as possible. Defer non-critical resources.
  2. Minimize Bytes: Reduce the total amount of data that needs to be downloaded.
  3. Reduce Round Trips: Minimize the number of requests between the browser and the server.
  4. Optimize Rendering: Help the browser render the page efficiently.
  5. Utilize Caching: Store resources locally on the user’s device to speed up subsequent visits.

III. Detailed Instructions to Improve LCP and FCP

A. Optimize Your Server and Hosting

  1. Choose a Fast Hosting Provider:
    • SSD-based hosting: Faster disk I/O.
    • Sufficient RAM and CPU: Ensure your server can handle traffic efficiently.
    • Located near your target audience: Reduces latency (Time To First Byte – TTFB).
  2. Use a Content Delivery Network (CDN):
    • How it helps: CDNs store copies of your website’s static assets (images, CSS, JS) on servers geographically closer to your users. This significantly reduces latency and TTFB for those assets.
    • Action: Implement a CDN like Cloudflare, Akamai, Amazon CloudFront, Google Cloud CDN, etc.
  3. Optimize Server Response Time (TTFB):
    • Database Optimization:
      • Efficient queries: Optimize SQL queries, add indexes to frequently queried columns.
      • Regular cleanup: Remove old data, optimize table structures.
      • Caching: Implement database caching for frequently accessed data.
    • Server-Side Caching:
      • Page caching: Cache entire HTML pages to avoid regenerating them on every request. (e.g., WP Super Cache, W3 Total Cache for WordPress; Varnish, Redis for more general setups).
      • Object caching: Cache database query results or API responses.
    • Server Configuration:
      • Keep-Alive: Enable HTTP Keep-Alive to allow multiple requests over a single TCP connection.
      • Latest PHP/Python/Node.js versions: Newer versions are generally faster.
      • Resource limits: Ensure your server isn’t hitting resource limits (CPU, memory).
    • Reduce chained critical requests: Each request adds latency. Minimize external script calls or API calls that block rendering.

B. Optimize Critical Rendering Path

  1. Minimize and Combine CSS:
    • Minification: Remove unnecessary characters (whitespace, comments) from CSS files.
    • Combination: Combine multiple CSS files into one (if not using HTTP/2 or HTTP/3, where multiple smaller files can be efficient due to multiplexing).
    • Action: Use build tools (Webpack, Gulp, Grunt), CDN features, or plugins (for CMS like WordPress) to automate this.
  2. Extract Critical CSS (Above-the-Fold CSS):
    • How it helps: Inline the CSS required for the immediate viewport directly into the HTML <head>. This allows the browser to render the visible content without waiting for external CSS files to download.
    • Action: Use tools like Critical, or manually identify and extract this CSS. Load the remaining CSS asynchronously (<link rel="preload" as="style" onload="this.onload=null;this.rel='stylesheet'">).
  3. Defer Non-Critical JavaScript:
    • How it helps: JavaScript can block HTML parsing and rendering. Deferring scripts prevents them from holding up the initial page load.
    • Action:
      • Use defer attribute: <script src="script.js" defer></script> – Executes script after HTML parsing is complete, but before DOMContentLoaded.
      • Use async attribute: <script src="script.js" async></script> – Executes script as soon as it’s downloaded, asynchronously, and does not block HTML parsing. Use for independent scripts.
      • Move non-critical JS to the end of the <body> tag.
      • Use JavaScript module type="module" with defer by default.
  4. Inline Small CSS/JS: For very small, critical CSS or JS snippets, inlining them directly into the HTML can save an HTTP request. Be cautious, as it reduces cacheability.
  5. Preload Key Requests:
    • How it helps: Tell the browser to fetch a resource that will be needed soon, before the browser discovers it naturally. Useful for fonts, hero images, or critical JS.
    • Action: Add <link rel="preload" href="path/to/resource" as="resource_type"> in the <head>.

C. Optimize Images and Media

Images are often the largest contributors to LCP and FCP issues.

  1. Compress Images:
    • Lossy vs. Lossless: Use lossy compression where quality loss is acceptable (e.g., JPEGs for photos). Use lossless for images where exact pixel reproduction is crucial (e.g., PNGs for logos).
    • Tools: Image optimization plugins (for CMS), online tools (TinyPNG, Squoosh), or build tools.
  2. Serve Images in Next-Gen Formats:
    • How it helps: Formats like WebP and AVIF offer superior compression and quality compared to JPEG or PNG, resulting in smaller file sizes.
    • Action: Convert existing images. Use <picture> element with <source> to provide fallback for browsers that don’t support the newer formats:HTML<picture> <source srcset="image.webp" type="image/webp"> <img src="image.jpg" alt="Description"> </picture>
  3. Serve Responsive Images:
    • How it helps: Deliver different image sizes based on the user’s device and screen resolution, preventing large images from being downloaded on small screens.
    • Action: Use srcset and sizes attributes with the <img> tag:HTML<img src="small.jpg" srcset="small.jpg 480w, medium.jpg 800w, large.jpg 1200w" sizes="(max-width: 600px) 480px, (max-width: 1000px) 800px, 1200px" alt="Description">
  4. Lazy Load Offscreen Images and Videos:
    • How it helps: Load images and videos only when they enter the viewport, reducing initial page load time and bandwidth usage.
    • Action:
      • Native lazy loading: <img src="image.jpg" loading="lazy"> (supported by modern browsers).
      • JavaScript libraries (e.g., lazysizes) for older browser compatibility or more advanced features.
  5. Specify Image Dimensions:
    • How it helps: Prevents Cumulative Layout Shift (CLS) and helps the browser reserve space for the image, improving rendering efficiency.
    • Action: Always include width and height attributes for <img> tags.
  6. Optimize Background Images: If your LCP element is a background image, ensure it’s optimized and consider preloading it if it’s critical.

D. Optimize Fonts

Web fonts can be a significant performance bottleneck.

  1. Host Fonts Locally (if possible): Avoid external font services if you can self-host, as it eliminates DNS lookups and additional HTTP requests.
  2. Preload Critical Fonts: If your website relies heavily on custom fonts for LCP text, preload them.HTML<link rel="preload" href="/fonts/your-font.woff2" as="font" type="font/woff2" crossorigin>
  3. Use font-display Property:
    • How it helps: Controls how fonts are displayed while they are loading.
    • Action:
      • font-display: swap;: Shows fallback text immediately and swaps in the custom font once loaded. Good for LCP as text is visible quickly.
      • font-display: optional;: Uses the custom font only if it loads quickly; otherwise, it sticks with the fallback.
  4. Subset Fonts: Include only the characters you need from the font file, reducing its size.
  5. Use WOFF2 Format: WOFF2 offers better compression than WOFF or TTF.

E. Implement Caching Strategies

  1. Browser Caching (HTTP Caching):
    • How it helps: Instructs browsers to store copies of your static assets locally, so subsequent visits don’t require re-downloading them.
    • Action: Configure Cache-Control and Expires headers on your server for static assets (images, CSS, JS, fonts). Set long expiration times (e.g., Cache-Control: public, max-age=31536000).
  2. Service Workers (for Advanced Caching):
    • How it helps: Provides granular control over caching, allowing you to precache resources, serve content offline, and implement advanced caching strategies (e.g., “cache-first” or “network-first”).
    • Action: Implement a Service Worker for a more robust caching solution.

F. Code Optimization

  1. Minify HTML: Remove unnecessary whitespace and comments from your HTML.
  2. Reduce DOM Size:
    • How it helps: A large and complex DOM tree can increase memory usage and make styling and script execution slower.
    • Action: Simplify your HTML structure, avoid excessive nesting.
  3. Optimize JavaScript Execution:
    • Reduce Payload: Only send the JavaScript that is strictly necessary.
    • Code Splitting: Break down large JavaScript bundles into smaller, on-demand chunks.
    • Tree Shaking: Remove unused code from your JavaScript bundles.
    • Web Workers: Offload computationally intensive tasks to background threads to avoid blocking the main thread.
  4. Efficient CSS Selectors: Complex CSS selectors can slow down rendering. Keep them as simple as possible.

G. Tools and Monitoring

  1. Google PageSpeed Insights:
    • How it helps: Provides performance scores for both mobile and desktop, along with specific recommendations and an LCP element identification.
    • Action: Use it regularly to track progress and identify new issues.
  2. Lighthouse (in Chrome DevTools):
    • How it helps: Similar to PageSpeed Insights, provides a detailed audit of your page’s performance, accessibility, SEO, and best practices.
    • Action: Run audits locally during development.
  3. WebPageTest:
    • How it helps: Offers advanced testing capabilities from various locations and network conditions, providing waterfall charts and detailed timing information.
    • Action: Use for in-depth analysis and to simulate real-world user conditions.
  4. Chrome DevTools (Performance Tab):
    • How it helps: Provides a detailed breakdown of what’s happening during page load, including network requests, rendering, scripting, and layout.
    • Action: Essential for debugging performance issues.
  5. Real User Monitoring (RUM):
    • How it helps: Tools like Google Analytics, Raygun, or custom RUM solutions track actual user performance data, giving you insights into how your site performs for real visitors across different devices and network conditions.
    • Action: Implement RUM to get a holistic view of your performance.

IV. Iterative Approach and Continuous Improvement

Website optimization is not a one-time task.

  1. Measure, Optimize, Verify:
    • Measure your current performance.
    • Implement one or a few optimizations.
    • Verify the impact of your changes using the tools mentioned above.
  2. Focus on the Biggest Wins First: Address the issues that have the largest impact on your Core Web Vitals. PageSpeed Insights often highlights these.
  3. Monitor Regularly: Website content, code, and user behavior change. Regular monitoring ensures your site remains fast.

By systematically addressing these areas, you will significantly improve your website’s speed, leading to better user experience, higher engagement, and potentially improved search engine rankings. Good luck!