Website responsiveness can materially affect user experience and conversion. Scanlyst evaluates Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS), helping teams identify assets, scripts, and server latency that deserve attention.
Well below the 2.5s good threshold
Immediate UI response on tap/click
Zero disruptive visual movement
Global edge CDN response benchmark
Microsecond-level performance profiling across synthetic 4G/5G mobile throttles and desktop viewport environments.
Comprehensive field and lab measurements for LCP, INP, CLS, FCP (First Contentful Paint), and TTFB.
Identifies heavy JavaScript evaluation tasks exceeding 50ms that freeze user interactions and degrade INP.
Audits images for next-generation AVIF/WebP compression, missing explicit width/height tags, and eager offscreen loading.
Verifies Brotli/Gzip text compression and immutable cache-control headers on static CSS, JS, and font assets.
Checks font-display: swap behavior, self-hosted WOFF2 assets, and preconnect hints to avoid FOIT and FOUT shifts.
Discovers oversized third-party vendor bundles, duplicate package versions, and non-critical CSS blocking rendering.
Throttled mobile audit matching Google Lighthouse & CrUX real-world testing environments.
Benchmarked using methodologies defined by the W3C Web Performance Working Group and the Chrome UX Report.
Official Google data source for 75th-percentile real-world user experience benchmarks.
Standardized browser metrics API for accurate high-resolution performance monitoring.
Calibrated lab auditing engine measuring performance under reproducible simulated conditions.
Zero-RTT connection handshaking for reduced packet loss latency on cellular connections.
Pinpoint render-blocking scripts, unoptimized assets, and layout shifts in seconds with our automated performance scanner.