Understand how your website's speed impacts user experience and search rankings
of users abandon websites that take more than 3 seconds to load
is the optimal page load time for maximum user engagement
decrease in customer satisfaction for every additional second of load time
of consumers say page speed affects their willingness to purchase from an online retailer
Google considers page speed as a ranking factor. Faster websites are more likely to rank higher in search results, especially on mobile.
A 1-second delay in page response can result in a 7% reduction in conversions. Faster sites convert more visitors into customers.
Fast-loading websites create a smoother, more enjoyable user experience, leading to longer visits and more page views.
Faster sites perform better in regions with slower internet connections, expanding your global reach.
Measures how long it takes for the browser to receive the first byte of data from the server. Good TTFB should be under 200ms.
Measures when the browser renders the first bit of content from the DOM. Target: Under 1.8 seconds for a good user experience.
Measures when the largest content element becomes visible. Good LCP should be under 2.5 seconds.
Measures how long it takes for the page to become fully interactive. Aim for under 3.8 seconds for good performance.
Measures the total time that the main thread was blocked enough to prevent input responsiveness. Target: Under 200ms.
Measures the sum of all unexpected layout shifts during the loading of a page. Good CLS should be under 0.1.
Each file your page loads (CSS, JavaScript, images) requires an HTTP request. Fewer requests generally lead to faster load times.
The total size of all resources loaded by your page. Larger pages require more bandwidth and typically load more slowly.
Analysis of image formats, sizes, and compression. Properly optimized images can significantly reduce page size.
Evaluation of code minification, compression, and unnecessary code. Streamlined code loads faster.
How quickly your server responds to browser requests. Slow servers delay every aspect of page loading.
Analysis of cache headers and browser caching implementation. Proper caching speeds up return visits.
Measures the time from when a user first interacts with your site to when the browser can respond to that interaction.
Measures how quickly content is visually displayed during page load. Lower scores mean content appears faster.
How fast a site feels to users, which can differ from actual load time. Techniques like skeleton screens improve perception.
Identification of CSS and JavaScript that prevent the page from rendering quickly.
Comparison of performance across device types. Mobile performance is particularly important for SEO.
Analysis of how quickly the visible portion of the page loads, which impacts user perception more than total page load time.
Core Web Vitals are a set of specific factors that Google considers important in a webpage's overall user experience. They're critical for SEO performance and user satisfaction.
What it measures: Loading performance - how quickly the main content of a page loads.
Good score: Under 2.5 seconds
What it measures: Interactivity - how quickly your page responds to user interactions.
Good score: Under 100 milliseconds
What it measures: Visual stability - how much elements move around as the page loads.
Good score: Under 0.1
Problem: Large images that aren't properly compressed or correctly sized for their display dimensions.
Solution: Compress images, use modern formats like WebP, implement responsive images, and lazy-load images below the fold.
Problem: CSS and JavaScript that prevent the page from rendering until they're fully loaded and processed.
Solution: Defer non-critical JavaScript, inline critical CSS, use async/defer attributes, and minimize critical rendering path resources.
Problem: Resources are downloaded on every page visit instead of being stored locally in the browser cache.
Solution: Configure proper cache headers with appropriate expiration times for static resources like images, CSS, and JavaScript files.
Problem: The server takes too long to respond to browser requests, delaying the entire page loading process.
Solution: Optimize server configuration, upgrade hosting, use a CDN, optimize database queries, and implement server-side caching.
Problem: Text-based resources (HTML, CSS, JavaScript) are sent without compression, increasing download times.
Solution: Enable GZIP or Brotli compression on your server to reduce text-based resource sizes by 70-90%.
Problem: Each resource requires a separate HTTP request, adding connection overhead and slowing down page loading.
Solution: Combine CSS/JS files, use CSS sprites, implement icon fonts, and consider HTTP/2 which handles multiple requests more efficiently.