Document response uses gzip; brotli would be ~20% smaller
REVIEW
Document response uses gzip; brotli would be ~20% smaller
Info::
i
Main HTML response uses gzip (brotli would be ~20% smaller)
All current browsers support brotli. Most CDNs (Cloudflare, Fastly, AWS CloudFront, Vercel, Netlify) can switch from gzip to brotli with a single config flag. Origin servers (nginx, Apache) need a brotli module compiled in -- nginx-brotli or Apache mod_brotli.
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
Page Weight Budget
899 KB transferred, 56 requests
PASS
899 KB transferred, 56 requests
Info::
✓
Page weighs 2.5 MB (899 KB transferred)
Info::
i
56 HTTP requests
Info::
i
Estimated 0.18 g CO2 per page load
899 KBtransferred
56 requests
0.18 g CO2 per page load
Images425.8 KiB47%
HTML186.3 KiB21%
JavaScript148.1 KiB16%
Fonts125.1 KiB14%
CSS11.9 KiB1%
Other2.1 KiB0%
02.4 MB4.9 MB
Under budget
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 (90.1 KiB of 899.3 KiB)
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+
Font Loading
10 fonts (125 KB)
PASS
10 fonts (125 KB)
Info::
i
10 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
10
125 KB total
Render-blocking
0
of 10
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
pxiEyp8kv8JHgFVrJJfecg....woff2swap
Size8 KB
Load time24 ms
Start817 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLEj6Z1x...woff2swap
Size8 KB
Load time18 ms
Start819 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLCz7Z1x...woff2swap
Size8 KB
Load time15 ms
Start820 ms
RiskFOUT — text flashes from fallback to web font
LDIoaomQNQcsA88c7O9yZ4K...woff2swap
Size27 KB
Load time24 ms
Start820 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLDD4Z1x...woff2swap
Size8 KB
Load time31 ms
Start820 ms
RiskFOUT — text flashes from fallback to web font
pxiDyp8kv8JHgFVrJJLm111...woff2swap
Size9 KB
Load time31 ms
Start822 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLGT9Z1x...woff2swap
Size8 KB
Load time20 ms
Start822 ms
RiskFOUT — text flashes from fallback to web font
pxiDyp8kv8JHgFVrJJLmr19...woff2swap
Size9 KB
Load time24 ms
Start822 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLBT5Z1x...woff2swap
Size7 KB
Load time26 ms
Start823 ms
RiskFOUT — text flashes from fallback to web font
themify.woffwoffswap
Size35 KB
Load time30 ms
Start1.5 s
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
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)
Fixing the unchecked items could save ~11 KB and ~22 ms
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+
HTTP/3 (QUIC)
HTTP/3 advertised via Alt-Svc
PASS
HTTP/3 advertised via Alt-Svc
Info::
✓
HTTP/3 (QUIC) is supported
First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.
A
Asset Compression
1 of 1 asset host still on gzip
PASS
1 of 1 asset host still on gzip
Info::
i
www.googletagmanager.com serves assets with gzip; brotli would be ~20% smaller (assets: 3)
Every current browser accepts brotli. On a CDN this is a per-pull-zone toggle (Cloudflare, Fastly, CloudFront, CDN77, Bunny all expose it); on an origin it needs the brotli module (nginx-brotli, Apache mod_brotli). The saving lands on the assets this host serves, not on the HTML document -- the document's own encoding is reported separately.
The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).
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).