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Published Oct 11, 2023 ⦁ 7 min read

Is Your Website Up to Speed?

With website load times being a key ranking factor for Google and a make-or-break metric for visitor engagement, optimizing the speed of your website is crucial for success. Studies show that 40% of visitors will abandon a web page if it takes over 3 seconds to load. For e-commerce sites, even minor delays can result in huge losses in revenue. But speed optimization can seem overwhelming with many moving parts to consider. This guide will cover actionable tips to analyze and improve website speed through core web vitals metrics, image compression, JavaScript optimization, caching, database performance, server improvements, and more. Faster load times lead to better user experience, SEO, and conversions - so let's dive in to ensure your website is up to speed.

First, we'll look at auditing your current website speed to identify bottlenecks. Online tools like Pingdom, WebPageTest, Google PageSpeed Insights and DevHunt provide detailed performance reports to analyze. Key metrics to track include page load time, Time to First Byte (TTFB), First Contentful Paint (FCP), and Largest Contentful Paint (LCP). These tools help uncover performance issues like bloated images, unoptimized JavaScript, and other factors slowing down your site.

Auditing Your Current Web Page Speed

When starting a website performance optimization project, the first step is understanding your current speed metrics. There are many free online tools to help audit and pinpoint problem areas:

Useful Online Tools

  • Pingdom provides a free website speed test and performance report showing page load time, requests, and web performance grades.

  • WebPageTest generates highly detailed metrics on page load times, requests, sizes, and optimization suggestions. You can test from different locations worldwide.

  • Google PageSpeed Insights analyzes site performance on mobile and desktop using Google's recommendations and best practices. It identifies opportunities to improve speed.

  • DevHunt offers website speed testing focused on developer sites and stacks. It benchmarks performance against peers.

  • Chrome DevTools can audit site performance right within the Chrome browser itself. Useful for quick tests during development.

Key Metrics to Track

  • Page load time measures how long it takes for the entire page to fully render in the browser. This should be under 3 seconds on mobile.

  • Time to first byte (TTFB) tracks how long the server takes to respond and send back the first byte of information. Faster is better.

  • First contentful paint (FCP) notes when initial content renders on the page - aim for under 1 second.

  • Largest contentful paint (LCP) identifies when the largest content element, like a hero image, loads.

Analyzing these web performance metrics will shed light on the weakest points of your website. Bottlenecks may include oversized images, unoptimized JavaScript, or a slow database. Comparing mobile versus desktop performance is also insightful. With this initial audit, you can set a performance benchmark to improve upon.

Optimizing Images

Images often account for most of a web page's transferred bytes, so optimizing images can yield significant speed improvements. Here are some key image optimization tips:

  • Compress images to reduce file sizes using tools like TinyPNG or Squoosh.

  • Resize images to exact display dimensions - don't just scale them down.

  • Use modern image formats like WebP and AVIF that have better compression.

  • Serve responsive images to send smaller files to mobile devices.

  • Lazy load images below the fold to delay loading until needed.

  • Cache images to prevent unnecessary re-downloads.

For example, AcmeTech compressed their product images from 500 KB to 100 KB each and saw their homepage load time drop from 8 seconds to under 2 seconds as a result.

Image Compression

  • Use TinyPNG, Squoosh or other tools to compress JPG and PNG images by removing unnecessary data.

  • Resize images to their true display dimensions before compressing - don't just scale them down.

  • Adjust JPG quality levels to find the sweet spot around 60-80% for small file sizes.

  • Compare WebP and AVIF formats, which often provide 25-35% better compression than JPG/PNG.

Responsive Images

  • Leverage srcset and sizes attributes to serve images optimized for the viewer's screen size.

  • Generate multiple sizes of each image during build process for optimal responsive loading.

  • The SRCN web standard allows responsive image resizing in the browser.

  • Match image breakpoints to CSS media query breakpoints for efficiency.

Following these best practices for advanced image optimization can significantly boost website speed.

Optimizing JavaScript

After images, JavaScript files are typically the largest assets downloaded by websites. Optimizing JavaScript improves page load times and overall site speed. Here are key tips:

  • Minify JavaScript code by removing whitespace, comments and unnecessary code to reduce file sizes.

  • Concatenate multiple scripts into fewer downloaded files to limit requests.

  • Defer non-critical JavaScript using async/defer attributes to load it asynchronously.

  • Lazy load below-the-fold scripts to delay loading until needed.

  • Enable caching of JavaScript files to prevent repeats.

For example, CodeWiz minified and concatenated their JavaScript bundles, reducing the total size from 1.5MB to 500KB. This sped up their site performance by over 30%.

JS Minification and Concatenation

  • Use Uglify, Terser or other tools to automatically minify JavaScript.

  • Concatenate JS files used across multiple pages into combined scripts.

  • Take care not to break dependencies when concatenating scripts.

  • Use code splitting to break up JS bundles into logical chunks that can load asynchronously.

Asynchronous JS Loading

  • Add defer attributes to non-critical JS includes to delay loading.

  • Use async for independent scripts that don't depend on other code.

  • Lazy load JS not needed for above-the-fold content using libraries like Lazysizes.

  • Code split bundles to prevent loading unnecessary JavaScript per page.

Following leading practices for optimizing JavaScript improves performance.

Enabling Caching

Implementing caching serves assets from the browser cache rather than re-downloading, providing huge speed improvements. Key tips:

  • Set cache headers on static assets to enable browser caching for specified time periods.

  • Fingerprint asset filenames to cache bust updated files with unique names.

  • Enable CDN caching for faster asset delivery worldwide.

  • Watch out for overaggressive caching leading to stale content.

  • Invalidate caches after deployments to serve new code immediately.

Cache busting involves appending a unique string to filenames like style.css?v2 to force browsers to download the new version. CDNs like Cloudflare cache assets at edge locations for faster performance.

Proper caching provides tremendous web performance lifts by minimizing requests. WidgetCorp saw 75% faster load times after implementing enhanced caching techniques.

Optimizing Server Performance

Beyond front-end optimizations, improving server-side speed also pays dividends for site performance. Consider these tips:

  • Tune database queries and indexes for lean performance. Add indexes to highly filtered fields.

  • Implement server-side caching with Redis, Memcached or similar to reduce database hits.

  • Enable compression such as gzip or brotli to shrink response payload sizes.

  • Limit redirects and avoid extra round trips.

For instance, Opsware improved slow query performance by 500% through indexing and optimization. They also cached data lookups, speeding up API response times.

Database Optimization

  • Add database indexes on frequently filtered or joined fields to improve query speeds.

  • Tune expensive queries and procedures to optimize performance.

  • Use database caching to return data faster while reducing load.

Other Server-Side Improvements

  • Implement server-side caching using Redis, Memcached or similar to reduce database queries.

  • Compress text-based assets like HTML, CSS, JavaScript and JSON.

  • Avoid unnecessary redirects that trigger extra network round trips.

Optimizing database and server-side performance prevents backend bottlenecks that slow down websites.

Summary and Conclusion

With a thorough audit, you can identify and prioritize website speed optimization opportunities. Focus on improving images, JavaScript, caching, databases, servers, and other areas. Faster site speed provides better user experience, SEO, and conversions. Regularly measure performance using online tools to monitor improvements over time. Web performance optimization is an ongoing process as new techniques and standards emerge. By following the tips outlined in this guide, you can ensure your website is up to speed.

OptimizationPerformanceWeb-Development

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