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.
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.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
Third-party code accounts for 7% of page weight (493.5 KiB of 7.0 MiB)
Info::
✓
Third-party blocking time is low (0 ms)
93%
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
2 fonts (85 KB)
PASS
2 fonts (85 KB)
Info::
i
2 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
2
85 KB total
Render-blocking
0
of 2
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
UcC73FwrK3iLTeHuS_nVMrM...woff2swap
Size47 KB
Load time46 ms
Start513 ms
RiskFOUT — text flashes from fallback to web font
nuFiD-vYSZviVYUb_rj3ij_...woff2swap
Size38 KB
Load time46 ms
Start513 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+
Compression Algorithm
Main response uses brotli
PASS
Main response uses brotli
Info::
✓
Main HTML response uses brotli (Content-Encoding: br)
Brotli is the best text-compression algorithm for general use, ~20% smaller than gzip on average (40% on smaller files). Modern browsers all support it.
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+
Main HTML Cache-Control
Main HTML max-age=0 (≤ 5min) is appropriate
PASS
Main HTML max-age=0 (≤ 5min) is appropriate
Info::
✓
Main HTML max-age=0 (≤ 5min) is appropriate
Got: public, max-age=0, must-revalidate
A
Server Response Intelligence
2 server-response signal(s) detected
PASS
2 server-response signal(s) detected
Warning::
!
Compressed response missing `Vary` header
The page is served with `Content-Encoding: br` but has no `Vary` header. Without `Vary: Accept-Encoding`, intermediary caches (corporate proxies, ISP caches) may serve the compressed variant to clients that didn't send the matching `Accept-Encoding` -- the client sees garbled bytes. Add `Vary: Accept-Encoding` whenever the response is conditionally compressed.
Info::
✓
Both `ETag` and `Last-Modified` present -- efficient revalidation supported
The page returns both `ETag` (content hash) and `Last-Modified` (timestamp) headers. Browsers can issue conditional GETs with `If-None-Match` or `If-Modified-Since`; the server returns 304 Not Modified for unchanged content, saving bandwidth. ETag is the more reliable of the two (timestamps fail in DST transitions and clock skew).
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
✓
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
A+
JavaScript Blocking
No render-blocking JS or document.write usage detected
PASS
No render-blocking JS or document.write usage detected
Info::
✓
No JavaScript blocking issues detected
A+
CSS Performance Depth
No CSS performance depth issues detected
PASS
No CSS performance depth issues detected
Info::
✓
No CSS performance depth issues detected
Network Waterfall
33 requests over 1516ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
16%of JavaScript execution is third-party
First-party Third-party277ms · 286KB · $4/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
Google Tag Manager
www.googletagmanager.com
Tag Manager
157ms
166 KB
43%
$2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
119ms
120 KB
54%
$2/mo
Optional
Google Tag Manager
Tag Manager
Optional
Execution157ms
Transfer166 KB
Unused43%
Monthly Cost$2/mo
Google Tag Manager
Tag Manager
Optional
Execution119ms
Transfer120 KB
Unused54%
Monthly Cost$2/mo
54% of Google Tag Manager's code is unused. The script may be loading features you don't use.
Why this matters
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
380 ms
2.7 s
3.0 s