Performance Analyzer
Monitor Core Web Vitals with Lighthouse-compatible scoring using this performance tool from DevTools Suite. Track LCP, FCP, CLS, INP, and TTFB in real-time.
Core Web Vitals Analysis Made Simple
Performance Analyzer measures the metrics that matter most for user experience. Using the same scoring methodology as Lighthouse, get a 0-100 performance score with detailed breakdowns of LCP, FCP, CLS, INP, and TTFB. Test across desktop, tablet, and mobile viewports with resource analysis and optimization recommendations.
Key Features
Everything you need for performance optimization
Lighthouse-Aligned Scoring
0-100 performance score using exact Lighthouse methodology with log-normal distribution calculations. Weighted composite: LCP 25%, INP 30%, CLS 25%, FCP 10%, TTFB 10%.
Largest Contentful Paint (LCP)
Measures when the largest content element renders. Target: ≤2.5s for "Good". Shows which element contributes to LCP with attribution details.
Cumulative Layout Shift (CLS)
Quantifies visual stability and unexpected layout changes. Target: ≤0.1 for "Good". Identifies elements causing layout shifts with attribution data.
Interaction to Next Paint (INP)
Measures responsiveness to user interactions. Target: ≤200ms for "Good". Shows which interaction triggers INP measurements with target detection.
First Contentful Paint (FCP)
Tracks initial content paint time. Target: ≤1.8s for "Good". Measures when the first text or image is rendered to the screen.
Time to First Byte (TTFB)
Captures server response time. Target: ≤800ms for "Good". Measures the time from request to the first byte of the response.
Multi-Viewport Testing
Test performance across desktop (1280x800), tablet (768x1024), and mobile (375x667) viewports. Understand how performance scales across device sizes.
Resource Analysis
Categorized breakdown of JavaScript, CSS, images, and fonts. Shows file size, count, and blocking status. Identifies render-blocking resources.
DOM Analysis
DOM node count (alert at >1500), nesting depth (alert at >32 levels), body children count. Detects inline scripts and styles for optimization opportunities.
Image Optimization Detection
Identifies images without lazy loading and oversized images larger than their display size. Shows waste percentage for optimization opportunities.
Export Reports
Export as JSON with full analysis data or CSV for spreadsheet analysis. Timestamped reports include URL, vitals, resources, diagnostics, and overall score.
Grade-Based Ratings
A-F grading system: A (90+), B (80-89), C (70-79), D (60-69), F (<60). Quick visual understanding of overall performance health.
Real User Metrics
Measures actual user experience, not simulated conditions.
Lighthouse Compatible
Same scoring methodology for consistent, comparable results.
Actionable Diagnostics
Specific recommendations for DOM, images, and resources.