Visualize Your Website's Resource Loading

LoadTime Analyzer is a free web performance analysis tool that helps you visualize and understand your website's resource loading behavior. It generates interactive waterfall charts showing exactly when and how each resource (JavaScript, CSS, images, fonts) loads on your page.

LoadTime Analyzer uses your browser's built-in Performance API to capture detailed timing information about every resource your website loads. All analysis happens locally in your browser - we never send your data to our servers. This ensures privacy while providing accurate, real-time performance insights.

Waterfall charts show the loading timeline of every resource on your page. You can identify render-blocking resources that delay first paint, spot slow third-party scripts, find large assets that need optimization, and understand the critical rendering path. This helps prioritize performance improvements that will have the biggest impact.

Yes! LoadTime Analyzer is completely free to use. There are no usage limits, no account required, and no credit card needed. We believe performance optimization tools should be accessible to all developers.

No. All performance analysis happens locally in your browser using the Performance API. Your analysis results are stored only in your browser's IndexedDB (local storage), never on our servers. You can clear your history at any time using the "Clear All" button.

LoadTime Analyzer works in all modern browsers that support the Performance API, including Chrome, Firefox, Safari, and Edge. For the best experience, we recommend using the latest version of your browser.

While Chrome DevTools is excellent for debugging, LoadTime Analyzer focuses specifically on making performance data easy to understand and share. We provide shareable reports, historical comparison, optimization recommendations, and a cleaner interface focused solely on resource loading performance.

Yes! Every analysis includes share buttons for Twitter, LinkedIn, and email. You can also copy a direct link that includes the URL you analyzed, making it easy to share findings with your team or discuss performance issues with colleagues.

Render-blocking resources are CSS and JavaScript files that prevent your browser from displaying content until they finish loading. These resources block the critical rendering path, delaying First Contentful Paint (FCP). LoadTime Analyzer identifies these resources and suggests fixes like using async or defer attributes, or inlining critical CSS.

Based on waterfall chart analysis, common optimizations include: compressing images and using modern formats (WebP/AVIF), enabling compression (gzip/brotli) for text resources, implementing proper caching headers, deferring non-critical JavaScript, minimizing third-party scripts, and reducing the size of CSS/JS bundles. LoadTime Analyzer highlights specific opportunities for each of these optimizations.

Third-party scripts (analytics, ads, social widgets) can significantly impact page performance but are often overlooked. They add extra DNS lookups, TCP connections, and download time. LoadTime Analyzer groups resources by domain so you can see exactly how much each third-party service costs in terms of load time and page size.

Time to First Byte (TTFB) measures how long it takes for your server to respond with the first byte of data after a browser requests it. High TTFB indicates server-side performance issues like slow database queries, lack of caching, or server overload. LoadTime Analyzer shows TTFB for each resource to help identify server-side bottlenecks.

Page speed is a ranking factor for Google. Use LoadTime Analyzer to identify and fix issues that hurt Core Web Vitals: optimize Largest Contentful Paint (LCP) by loading critical resources faster, reduce Cumulative Layout Shift (CLS) by properly sizing images, and improve First Input Delay (FID) by minimizing JavaScript execution time. Faster sites rank higher and provide better user experience.