Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
B
Page Weight Budget
1.2 MB transferred, 48 requests
REVIEW
1.2 MB transferred, 48 requests
Info::
✓
Page weighs 2.1 MB (1.2 MB transferred)
Info::
✓
48 HTTP requests
Info::
i
Estimated 0.24 g CO2 per page load
1.2 MBtransferred
48 requests
0.24 g CO2 per page load
Images806.5 KiB68%
JavaScript169.7 KiB14%
Fonts98.0 KiB8%
CSS52.2 KiB4%
Other26.7 KiB2%
HTML18.8 KiB2%
Other9.4 KiB1%
Other816 B0%
02.4 MB4.9 MB
Under budget
B
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
i
HTTP/3 (QUIC) is not advertised
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.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW
Green Hosting
No green hosting detected
A+
Third-Party Impact
10% third-party, 0 ms blocking
PASS
10% third-party, 0 ms blocking
Info::
i
Third-party code accounts for 10% of page weight (121.8 KiB of 1.2 MiB)
Info::
✓
Third-party blocking time is low (0 ms)
90%
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
Image Optimization
12 images, 0 KB saveable
PASS
12 images, 0 KB saveable
Info::
✓
All images are well-optimized
12images807 KB
0oversized-0 KB
3legacy format
0missing dimensionsCLS risk
A+
Font Loading
4 fonts (98 KB)
PASS
4 fonts (98 KB)
Info::
i
4 font(s) use font-display: swap (FOUT risk but functional)
Consider code splitting or tree shaking to reduce unused code.
Why this matters
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
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
3 hints, 0 missing preconnects
PASS
3 hints, 0 missing preconnects
Info::
✓
Page uses 3 resource hint(s)
Current Resource Hints
preconnect—
preload
3
dns-prefetch—
prefetch—
3 resource hints configured
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::
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.
1 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.
A+
CSS Performance Depth
No CSS performance depth issues detected
PASS
No CSS performance depth issues detected
Info::
✓
No CSS performance depth issues detected
Asset Compression
No text asset hosts to measure
INFO
No text asset hosts to measure
Info::
i
No third-party or subdomain host served enough text assets to measure
Asset compression is measured per host, from one HEAD request against a sampled resource. Pages that serve all their JS and CSS from the document's own origin are covered by the document compression check instead.
Network Waterfall
48 requests over 2836ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Image Optimization
29 images, 63 KB total, 0 KB wasted
INFO
Image Optimization Audit
Total Images
29
Total Size
63 KB
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.