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6.52 Performance, Speed, Core Web Vitals & Rendering Quality

200 checks in Schema, Local, Trust, Deep Audit. Automated Its subsection has a live automated checker in the engine.

Core Web Vitals — LCP (Largest Contentful Paint)

ID	Check	Passes when	Weight	Runs
6.52.01	Validate LCP ≤ 2.5s on mobile	≤2.5s	Critical	Deterministic
6.52.02	Validate LCP ≤ 2.5s on desktop	≤2.5s	Critical	Deterministic
6.52.03	Detect if LCP element is an oversized hero image	None	Heavy	Deterministic
6.52.04	Validate LCP image preloaded	Preloaded	Heavy	Deterministic
6.52.05	Validate LCP served in optimal format (WebP/AVIF when available)	Optimal	Heavy	Deterministic
6.52.06	Detect unnecessary render-blocking delay before LCP	None	Medium	Deterministic
6.52.07	Validate early connection hints for LCP host	Present	Medium	Deterministic
6.52.08	Validate no JS-blocking LCP	None	Medium	Deterministic
6.52.09	Validate correct LCP candidate identified	Correct	Medium	Deterministic
6.52.10	Validate stable LCP across sessions (low variability)	Stable	Medium	Deterministic

Core Web Vitals — CLS (Cumulative Layout Shift)

ID	Check	Passes when	Weight	Runs
6.52.11	Validate CLS ≤ 0.1	≤0.1	Critical	Deterministic
6.52.12	Validate all images have width/height attributes	Present	Heavy	Deterministic
6.52.13	Detect layout shift from ads or injected elements	None	Heavy	Deterministic
6.52.14	Validate font loading strategy prevents flashes	Stable	Heavy	Deterministic
6.52.15	Validate iframe placeholders reserve space	Reserved	Medium	Deterministic
6.52.16	Detect dynamic content pushing layout unexpectedly	None	Medium	Deterministic
6.52.17	Validate animations not causing layout shifts	Stable	Medium	Deterministic
6.52.18	Validate stable component hydration preventing CLS	Stable	Medium	Deterministic
6.52.19	Validate no theme-switch CLS	None	Medium	Deterministic
6.52.20	Detect late-loading CSS causing visual jump	None	Medium	Deterministic

Core Web Vitals — INP/FID (Interaction Latency)

ID	Check	Passes when	Weight	Runs
6.52.21	Validate INP ≤ 200ms	≤200ms	Critical	Deterministic
6.52.22	Validate main-thread blocking JS minimized	Minimal	Heavy	Deterministic
6.52.23	Validate input event listeners efficient	Efficient	Heavy	Deterministic
6.52.24	Validate long tasks minimized (<50ms ideally)	Minimized	Heavy	Deterministic
6.52.25	Detect heavy client-side frameworks slowing input	None	Medium	Deterministic
6.52.26	Validate event delegation used correctly	Correct	Medium	Deterministic
6.52.27	Validate JS hydration not blocking input	Non-blocking	Medium	Deterministic
6.52.28	Detect custom scripts causing INP spikes	None	Medium	Deterministic
6.52.29	Validate passive event listeners where correct	Passive	Medium	Deterministic
6.52.30	Validate smooth interactivity on mobile devices	Smooth	Medium	Deterministic

TTFB (Time to First Byte) & Server Responsiveness

ID	Check	Passes when	Weight	Runs
6.52.31	Validate TTFB ≤ 0.8s	≤0.8s	Critical	Deterministic
6.52.32	Validate server proximity appropriate (global CDN)	Appropriate	Heavy	Deterministic
6.52.33	Validate no server-side delays in response chain	Minimal	Heavy	Deterministic
6.52.34	Validate stable server performance across multiple regions	Stable	Heavy	Deterministic
6.52.35	Detect cold-start penalties	None	Medium	Deterministic
6.52.36	Validate optimized backend logic	Optimized	Medium	Deterministic
6.52.37	Validate no unnecessary redirects before first byte	None	Medium	Deterministic
6.52.38	Validate compression applied before TTFB	Compressed	Medium	Deterministic
6.52.39	Validate DNS lookup time minimal	Minimal	Medium	Deterministic
6.52.40	Detect server throttling or intermittent TTFB spikes	None	Medium	Deterministic

Resource Delivery & Rendering Path Efficiency

ID	Check	Passes when	Weight	Runs
6.52.41	Validate render-blocking resources minimized	Minimal	Heavy	Deterministic
6.52.42	Validate CSS delivered in optimized order	Optimized	Heavy	Deterministic
6.52.43	Detect redundant script execution before rendering	None	Heavy	Deterministic
6.52.44	Validate JS deferred or async where appropriate	Deferred/Async	Heavy	Deterministic
6.52.45	Validate non-critical CSS split or lazyloaded	Split	Medium	Deterministic
6.52.46	Validate critical CSS applied inline or prioritized	Prioritized	Medium	Deterministic
6.52.47	Validate HTML delivered with minimal bloat	Minimal	Medium	Deterministic
6.52.48	Detect unnecessary DOM depth	Minimal	Medium	Deterministic
6.52.49	Validate efficient first paint timeline	Efficient	Medium	Deterministic
6.52.50	Validate preload/prefetch/prefetch hints used effectively	Effective	Medium	Deterministic

JavaScript Weight, Execution & Optimization

ID	Check	Passes when	Weight	Runs
6.52.51	Validate total JS payload ≤ 250kb compressed	≤250kb	Critical	Deterministic
6.52.52	Validate tree-shaking effective	Effective	Heavy	Deterministic
6.52.53	Detect unused JS modules	None	Heavy	Deterministic
6.52.54	Validate vendor bundle optimized	Optimized	Heavy	Deterministic
6.52.55	Validate framework hydration minimized	Minimal	Heavy	Deterministic
6.52.56	Validate code-splitting applied properly	Applied	Medium	Deterministic
6.52.57	Detect legacy polyfills shipped unnecessarily	None	Medium	Deterministic
6.52.58	Validate async/defer strategy consistent	Consistent	Medium	Deterministic
6.52.59	Validate minimal JS execution during early render	Minimal	Medium	Deterministic
6.52.60	Detect synchronous XHR calls	None	Medium	Deterministic

CSS Performance & Style Delivery

ID	Check	Passes when	Weight	Runs
6.52.61	Validate CSS correctly split by route	Split	Heavy	Deterministic
6.52.62	Validate CSS size ≤ 150kb compressed	≤150kb	Heavy	Deterministic
6.52.63	Detect unused CSS selectors	None	Heavy	Deterministic
6.52.64	Validate critical CSS extracted	Extracted	Heavy	Deterministic
6.52.65	Validate @font-face optimized (subsetted/fonts preloaded)	Optimized	Medium	Deterministic
6.52.66	Validate CSS not delaying FCP	Not delaying	Medium	Deterministic
6.52.67	Detect overly complex selectors	Minimal	Medium	Deterministic
6.52.68	Validate CSS used consistently across components	Consistent	Medium	Deterministic
6.52.69	Validate modern CSS features reduce bloat	Modern	Medium	Deterministic
6.52.70	Detect CSS blocking scripts unintentionally	None	Medium	Deterministic

Memory, Cpu, Thread Work & Runtime Performance

ID	Check	Passes when	Weight	Runs
6.52.71	Validate no runaway memory usage	Stable	Critical	Deterministic
6.52.72	Detect long JS tasks >200ms	None	Heavy	Deterministic
6.52.73	Validate CPU usage minimal during page idle	Minimal	Heavy	Deterministic
6.52.74	Validate no excessive layout thrashing	None	Heavy	Deterministic
6.52.75	Validate requestAnimationFrame used when appropriate	Correct	Medium	Deterministic
6.52.76	Validate GPU-accelerated animations where relevant	Accelerated	Medium	Deterministic
6.52.77	Detect heavy timers (setInterval/setTimeout misuse)	None	Medium	Deterministic
6.52.78	Validate minimal DOM manipulation per frame	Minimal	Medium	Deterministic
6.52.79	Detect unnecessary reflows/repaints	None	Medium	Deterministic
6.52.80	Validate smooth runtime behavior under load	Smooth	Medium	Deterministic

Hydration, SSR/CSR Balance & Rendering Strategy

ID	Check	Passes when	Weight	Runs
6.52.81	Validate SSR or SSG where applicable	Implemented	Heavy	Deterministic
6.52.82	Validate hydration cost minimized	Minimal	Heavy	Deterministic
6.52.83	Detect hydration mismatch warnings	None	Heavy	Deterministic
6.52.84	Validate partial hydration strategies used where possible	Applied	Heavy	Deterministic
6.52.85	Validate predictable rendering sequence	Predictable	Medium	Deterministic
6.52.86	Validate components load progressively	Progressive	Medium	Deterministic
6.52.87	Validate hydration not blocking interaction	Non-blocking	Medium	Deterministic
6.52.88	Detect unnecessary client-side rendering	None	Medium	Deterministic
6.52.89	Validate server-rendered HTML meaningful before hydration	Meaningful	Medium	Deterministic
6.52.90	Validate predictable hydration order for interactive components	Predictable	Medium	Deterministic

Network Request Optimization & Connection Management

ID	Check	Passes when	Weight	Runs
6.52.91	Validate number of network requests minimized	Minimal	Heavy	Deterministic
6.52.92	Validate resource concurrency balanced	Balanced	Heavy	Deterministic
6.52.93	Detect redundant API calls	None	Heavy	Deterministic
6.52.94	Validate HTTP/2 or HTTP/3 used	Correct	Medium	Deterministic
6.52.95	Validate DNS preconnect for heavy third-party domains	Present	Medium	Deterministic
6.52.96	Validate caching headers optimized	Optimized	Medium	Deterministic
6.52.97	Validate network waterfalls efficient	Efficient	Medium	Deterministic
6.52.98	Detect redundant font/API/image fetches	None	Medium	Deterministic
6.52.99	Validate keep-alive connections used effectively	Effective	Medium	Deterministic
6.52.100	Detect network-blocking 3rd-party scripts	None	Medium	Deterministic

Caching Systems & Storage Strategy

ID	Check	Passes when	Weight	Runs
6.52.101	Validate caching headers present for all static assets	Present	Critical	Deterministic
6.52.102	Validate long‑term caching for JS/CSS bundles	Long-term	Heavy	Deterministic
6.52.103	Detect incorrect or missing cache‑control headers	Correct	Heavy	Deterministic
6.52.104	Validate HTML caching strategy appropriate (SSR/CSR aware)	Appropriate	Heavy	Deterministic
6.52.105	Validate service workers used responsibly (no stale content traps)	Correct	Medium	Deterministic
6.52.106	Validate caching strategy supports preloading of warm paths	Supported	Medium	Deterministic
6.52.107	Detect unexpected cache bypass events	None	Medium	Deterministic
6.52.108	Validate stale‑while‑revalidate where beneficial	Applied	Medium	Deterministic
6.52.109	Validate ETag & Last‑Modified headers correct	Correct	Medium	Deterministic
6.52.110	Detect cache fragmentation	None	Medium	Deterministic

CDN Distribution & Global Performance

ID	Check	Passes when	Weight	Runs
6.52.111	Validate CDN enabled for all media & static assets	Enabled	Critical	Deterministic
6.52.112	Validate CDN edge coverage adequate for primary audience	Adequate	Heavy	Deterministic
6.52.113	Validate CDN origin shield enabled	Enabled	Heavy	Deterministic
6.52.114	Validate CDN caching rules optimized	Optimized	Heavy	Deterministic
6.52.115	Validate CDN image transformations active	Active	Medium	Deterministic
6.52.116	Validate CDN compression (Brotli/Gzip) enabled	Enabled	Medium	Deterministic
6.52.117	Detect edge cache evictions that cause slowdowns	None	Medium	Deterministic
6.52.118	Validate CDN routing uses HTTP/2 or HTTP/3	Correct	Medium	Deterministic
6.52.119	Validate CDN configuration consistent across subdomains	Consistent	Medium	Deterministic
6.52.120	Detect unwanted region‑specific performance issues	None	Medium	Deterministic

Image Optimization & Delivery

ID	Check	Passes when	Weight	Runs
6.52.121	Validate images delivered in next‑gen formats (WebP/AVIF)	Next‑gen	Critical	Deterministic
6.52.122	Detect oversized images relative to display size	None	Heavy	Deterministic
6.52.123	Validate responsive srcset/sizes attributes used	Present	Heavy	Deterministic
6.52.124	Validate lazyloading applied appropriately	Applied	Heavy	Deterministic
6.52.125	Validate image compression thresholds optimal	Optimal	Medium	Deterministic
6.52.126	Detect redundant high‑resolution assets	None	Medium	Deterministic
6.52.127	Validate icons/SVGs not rasterized unnecessarily	Correct	Medium	Deterministic
6.52.128	Detect large background images hurting performance	None	Medium	Deterministic
6.52.129	Validate image placeholders used for smooth loading	Present	Medium	Deterministic
6.52.130	Validate image CDN parameters correct (quality, resize, format)	Correct	Medium	Deterministic

Video Delivery & Streaming

ID	Check	Passes when	Weight	Runs
6.52.131	Validate videos streamed via optimized players	Optimized	Heavy	Deterministic
6.52.132	Validate video preload strategy correct	Correct	Heavy	Deterministic
6.52.133	Validate video resolution adapted to device bandwidth	Adaptive	Heavy	Deterministic
6.52.134	Validate muted autoplay only when permitted	Correct	Medium	Deterministic
6.52.135	Validate posters displayed to prevent blank frames	Present	Medium	Deterministic
6.52.136	Detect heavy self‑hosted videos slowing page	None	Medium	Deterministic
6.52.137	Validate video compression optimized (bitrate, codec)	Optimized	Medium	Deterministic
6.52.138	Validate streaming format correct (HLS/DASH)	Correct	Medium	Deterministic
6.52.139	Validate lazyloading for non‑critical videos	Applied	Medium	Deterministic
6.52.140	Detect excessive simultaneous video loads	None	Medium	Deterministic

Media Systems, Gifs, Lottie, and Interactive Assets

ID	Check	Passes when	Weight	Runs
6.52.141	Validate GIFs replaced with MP4/WebM where possible	Replaced	Heavy	Deterministic
6.52.142	Validate Lottie animations efficient and compressed	Efficient	Heavy	Deterministic
6.52.143	Validate 3D/interactive assets loaded progressively	Progressive	Heavy	Deterministic
6.52.144	Validate WebGL usage not excessive	Balanced	Medium	Deterministic
6.52.145	Validate inline SVGs optimized	Optimized	Medium	Deterministic
6.52.146	Detect oversized Lottie files	None	Medium	Deterministic
6.52.147	Validate animations controlled via CSS/JS efficiently	Efficient	Medium	Deterministic
6.52.148	Validate interactive media lazyloaded or gated	Gated	Medium	Deterministic
6.52.149	Detect excessive media transformations on client	None	Medium	Deterministic
6.52.150	Validate overall media pipeline efficient	Efficient	Medium	Deterministic

Third-Party Scripts, Tags & Framework Impact

ID	Check	Passes when	Weight	Runs
6.52.151	Validate total 3rd‑party JS cost acceptable	Minimal	Critical	Deterministic
6.52.152	Detect blocking third‑party tags delaying render	None	Heavy	Deterministic
6.52.153	Validate tag manager loads asynchronously	Async	Heavy	Deterministic
6.52.154	Validate ad scripts not causing layout shifts	Stable	Heavy	Deterministic
6.52.155	Validate analytics scripts defer/async	Deferred	Medium	Deterministic
6.52.156	Detect abandoned/legacy scripts	None	Medium	Deterministic
6.52.157	Validate consent mode properly configured	Correct	Medium	Deterministic
6.52.158	Validate pixel trackers not inflating network load	Minimal	Medium	Deterministic
6.52.159	Detect duplicate script loads	None	Medium	Deterministic
6.52.160	Validate social widgets loaded lazily	Lazyloaded	Medium	Deterministic

Security Impact on Performance

ID	Check	Passes when	Weight	Runs
6.52.161	Validate HTTPS negotiation fast & stable	Fast	Heavy	Deterministic
6.52.162	Validate HSTS enabled	Enabled	Heavy	Deterministic
6.52.163	Validate TLS 1.3 active	Active	Heavy	Deterministic
6.52.164	Validate certificate chain short	Short	Medium	Deterministic
6.52.165	Detect security headers causing blocking behavior	None	Medium	Deterministic
6.52.166	Validate secure cookies not impacting performance	Balanced	Medium	Deterministic
6.52.167	Detect repeated SSL handshake renegotiations	None	Medium	Deterministic
6.52.168	Validate CSP rules not blocking critical assets	Correct	Medium	Deterministic
6.52.169	Validate performance impact from bot filtering minimal	Minimal	Medium	Deterministic
6.52.170	Detect rate‑limit errors affecting UX	None	Medium	Deterministic

Performance Regression, Release Monitoring & Trend Analysis

ID	Check	Passes when	Weight	Runs
6.52.171	Validate no performance regression after new releases	None	Heavy	Deterministic
6.52.172	Validate synthetic + field data aligned	Aligned	Heavy	Deterministic
6.52.173	Validate month‑over‑month CWV stability	Stable	Heavy	Deterministic
6.52.174	Validate versioned deployments tracked	Tracked	Medium	Deterministic
6.52.175	Validate performance budgets enforced	Enforced	Medium	Deterministic
6.52.176	Detect regressions in render blocking	None	Medium	Deterministic
6.52.177	Validate Lighthouse/PSI scores consistent	Consistent	Medium	Deterministic
6.52.178	Validate trendlines improving QoQ	Improving	Medium	Deterministic
6.52.179	Validate high‑traffic pages prioritized	Prioritized	Medium	Deterministic
6.52.180	Detect API performance regressions	None	Medium	Deterministic

Final Performance Score, Stability & Delivery Validation

ID	Check	Passes when	Weight	Runs
6.52.181	Validate no critical rendering blockers remain	None	Critical	Deterministic
6.52.182	Validate CWV scores ≥ 90th percentile	≥90th	Critical	Deterministic
6.52.183	Validate global rendering stability	Stable	Heavy	Deterministic
6.52.184	Validate device‑type parity for performance	Parity	Heavy	Deterministic
6.52.185	Validate overall payload size optimized	Optimized	Medium	Deterministic
6.52.186	Validate backend + front‑end synergy (API + client)	Synergized	Medium	Deterministic
6.52.187	Validate latency distribution consistent	Consistent	Medium	Deterministic
6.52.188	Validate throughput unaffected by spikes	Stable	Medium	Deterministic
6.52.189	Detect long‑tail device performance issues	None	Medium	Deterministic
6.52.190	Validate image/video heavy pages optimized	Optimized	Medium	Deterministic

Final System Scoring

ID	Check	Passes when	Weight	Runs
6.52.191	Validate no major network or JS bottlenecks	None	Critical	Deterministic
6.52.192	Validate stable performance under load	Stable	Critical	Deterministic
6.52.193	Validate all performance optimizations respected	Respected	Heavy	Deterministic
6.52.194	Validate no regressions after caching/CDN pass	None	Heavy	Deterministic
6.52.195	Validate performance profile reproducible	Reproducible	Medium	Deterministic
6.52.196	Validate browser support coverage broad	Broad	Medium	Deterministic
6.52.197	Validate CPU/Memory footprints acceptable	Acceptable	Medium	Deterministic
6.52.198	Validate resource delivery efficient	Efficient	Medium	Deterministic
6.52.199	Validate rendering remains stable on slow networks	Stable	Medium	Deterministic
6.52.200	Compute Final Performance Score	Finalized	Critical	Deterministic

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