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
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.
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
23 fonts (528 KB)
PASS
23 fonts (528 KB)
Info::
i
23 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
23
528 KB total
Render-blocking
0
of 23
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
roboto-v51-latin-regula...woff2swap
Size22 KB
Load time36 ms
Start1.3 s
RiskFOUT — text flashes from fallback to web font
roboto-v51-latin-700.d8...woff2swap
Size22 KB
Load time34 ms
Start1.3 s
RiskFOUT — text flashes from fallback to web font
pro-fa-regular-400-0.woff2woff2swap
Size14 KB
Load time40 ms
Start1.6 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-13.woff2woff2swap
Size17 KB
Load time44 ms
Start1.6 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-12.woff2woff2swap
Size20 KB
Load time63 ms
Start1.6 s
RiskFOUT — text flashes from fallback to web font
pro-fa-brands-400-0.woff2woff2swap
Size37 KB
Load time44 ms
Start1.6 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-0.woff2woff2swap
Size15 KB
Load time68 ms
Start1.6 s
RiskFOUT — text flashes from fallback to web font
pro-fa-regular-400-12.w...woff2swap
Size19 KB
Load time46 ms
Start1.6 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-14.woff2woff2swap
Size17 KB
Load time54 ms
Start1.6 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-2.woff2woff2swap
Size28 KB
Load time44 ms
Start1.6 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-16.woff2woff2swap
Size23 KB
Load time53 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-regular-400-19.w...woff2swap
Size27 KB
Load time65 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-regular-400-14.w...woff2swap
Size16 KB
Load time65 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-regular-400-10.w...woff2swap
Size27 KB
Load time65 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-regular-400-2.woff2woff2swap
Size26 KB
Load time69 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-regular-400-1.woff2woff2swap
Size17 KB
Load time69 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-regular-400-21.w...woff2swap
Size25 KB
Load time68 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-brands-400-1.woff2woff2swap
Size40 KB
Load time69 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-19.woff2woff2swap
Size28 KB
Load time44 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-10.woff2woff2swap
Size30 KB
Load time44 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-1.woff2woff2swap
Size18 KB
Load time45 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
pro-fa-light-300-21.woff2woff2swap
Size28 KB
Load time45 ms
Start1.7 s
RiskFOUT — text flashes from fallback to web font
atkinson-hyperlegible-n...woff2swap
Size13 KB
Load time19 ms
Start2.2 s
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+
Document Compression
Document response uses brotli
PASS
Document 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+
Asset Compression
All 1 asset host use brotli
PASS
All 1 asset host use brotli
Info::
✓
app.tolkie.nl serves assets with brotli (assets: 3)
Got: app.tolkie.nl (text/css)
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
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::
i
No `ETag` or `Last-Modified` -- conditional GET not supported
Without either header, browsers can't issue conditional GETs and refresh always re-downloads the full response body even when nothing changed. Add `ETag: "<hash>"` (or `Last-Modified: <date>`) on cacheable responses; the server returns 304 Not Modified when the client's cached copy is still valid, saving bandwidth.
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Previder BV
Network Waterfall
76 requests over 3270ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers