HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.
C
Document Compression
Action
Document response served uncompressed
REVIEW
Document response served uncompressed
Info::
i
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
B
Main HTML Cache-Control
No Cache-Control header on main HTML response
REVIEW
No Cache-Control header on main HTML response
Info::
i
Main HTML response has no Cache-Control header
Without an explicit Cache-Control, browsers fall back to heuristic caching (~10% of Last-Modified age). Set `Cache-Control: no-cache` or `max-age=300` for HTML to control freshness explicitly -- prevents stale auth state and SPA shell drift.
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
i
No Server-Timing header found
Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.
B
JavaScript Blocking
1 JS blocking issue(s) detected
REVIEW
1 JS blocking issue(s) detected
Warning::
!
21 render-blocking <script src> tag(s) without async/defer
Each `<script src=...>` without `async`, `defer`, or `type="module"` blocks HTML parsing while the browser fetches and executes it. The block lasts the entire round-trip + execution time -- on slow networks this translates directly into LCP delay. Add `defer` (executes after parse, in source order) for scripts that interact with the DOM, or `async` (executes whenever ready) for analytics / independent scripts. Module scripts (`type="module"`) are deferred by default.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW
Green Hosting
No green hosting detected
A+
Third-Party Impact
5% third-party, 0 ms blocking
PASS
5% third-party, 0 ms blocking
Info::
i
Third-party code accounts for 5% of page weight (113.4 KiB of 2.4 MiB)
Info::
✓
Third-party blocking time is low (0 ms)
95%
First-party Third-party
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
✓
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
3 fonts (97 KB)
PASS
3 fonts (97 KB)
Info::
i
3 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
3
97 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
1Ptug8zYS_SKggPNyC0IT4t...woff2swap
Size42 KB
Load time50 ms
Start559 ms
RiskFOUT — text flashes from fallback to web font
nuFiD-vYSZviVYUb_rj3ij_...woff2swap
Size38 KB
Load time47 ms
Start559 ms
RiskFOUT — text flashes from fallback to web font
ke85OhoaMkR6-hSn7kbHVoF...woff2swap
Size17 KB
Load time28 ms
Start560 ms
RiskFOUT — text flashes from fallback to web font
Optimization checklist
Preload critical fonts (priority=high)
Use woff2 format for all fonts
Set font-display to swap, optional, or fallback
Subset large fonts (≤100 KB each)
A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
✓
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
✓
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
✓
No resource hint issues
A+
Asset Compression
All 1 asset host use brotli
PASS
All 1 asset host use brotli
Info::
✓
cdn.iubenda.com serves assets with brotli (assets: 4)
Got: cdn.iubenda.com (application/javascript)
A+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
✓
LCP image preload audit not available for this scan
A+
Server Response Intelligence
1 server-response signal(s) detected
PASS
1 server-response signal(s) detected
Info::
✓
`Last-Modified` present -- timestamp-based conditional GET supported
Consider also setting `ETag` for stronger revalidation -- ETags are content hashes that don't suffer from clock-skew or DST issues. Last-Modified alone is functional for conditional GETs and not a bug.
Each `<link rel="stylesheet">` without a non-blocking `media` attribute holds up the first paint. Browsers download all of them before painting any content. Consolidate into 1-2 critical-path stylesheets; defer non-critical CSS via `<link rel="stylesheet" media="print" onload="this.media='all'">` or via the loadCSS pattern; inline above-the-fold CSS in `<style>` to short-circuit the request entirely.
Network Waterfall
80 requests over 1210ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Real-User Performance (CrUX)
Field metrics from the Chrome User Experience Report
INFO
Chrome User Experience (CrUX)
Real-user metrics from the Chrome UX Report (2026-10-01 — 2026-10-28)
LCP (p75)
1572 ms
90% good
INP (p75)
0 ms
0% good
CLS (p75)
0.040
85% good
FCP (p75)
637 ms
TTFB (p75)
156 ms
Image Optimization
24 images, 241 KB total, 0 KB wasted
INFO
Image Optimization Audit
Total Images
24
Total Size
241 KB
7 missing alt text12 missing dimensions18 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.