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
HTTP Caching
public, max-age=0, s-maxage=3600
REVIEW
public, max-age=0, s-maxage=3600
Info::
✓
Cache-Control header is set
Got: public, max-age=0, s-maxage=3600
Info::
✓
CDN TTL: 1 hour (s-maxage=3600)
Info::
i
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control
public, max-age=0, s-maxage=3600
Directive
Value
Meaning
public
—
Any cache may store this response
max-age
0
Cache for 0 seconds
s-maxage
3600
CDN caches for 1 hour
A+
Third-Party Impact
17% third-party, 0 ms blocking
PASS
17% third-party, 0 ms blocking
Info::
i
Third-party code accounts for 17% of page weight (996.5 KiB of 5.7 MiB)
Info::
✓
Third-party blocking time is low (0 ms)
83%
17%
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
4 fonts (79 KB)
PASS
4 fonts (79 KB)
Info::
i
4 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
4
79 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
7cHpv4kjgoGqM7E_DMs5yng...woff2swap
Size15 KB
Load time21 ms
Start931 ms
RiskFOUT — text flashes from fallback to web font
7cHqv4kjgoGqM7E3t-4s51o...woff2swap
Size15 KB
Load time26 ms
Start931 ms
RiskFOUT — text flashes from fallback to web font
HTxwL3I-JCGChYJ8VI-L6OO...woff2swap
Size15 KB
Load time31 ms
Start932 ms
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size34 KB
Load time54 ms
Start1.7 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
1 hints, 0 missing preconnects
PASS
1 hints, 0 missing preconnects
Info::
✓
Page uses 1 resource hint(s)
Current Resource Hints
preconnect—
preload—
dns-prefetch
1
prefetch—
1 resource hints configured
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+
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, s-maxage=3600
A+
Server Response Intelligence
2 server-response signal(s) detected
PASS
2 server-response signal(s) detected
Info::
✓
`Vary` header declared: Accept-Encoding
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::
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+
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
1 JS blocking issue(s) detected
PASS
1 JS blocking issue(s) detected
Warning::
!
2 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.
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.
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Something Familiar
Network Waterfall
72 requests over 2146ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
48%of JavaScript execution is third-party
First-party Third-party941ms · 168KB · $16/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.gstatic.com
www.gstatic.com
Other
673ms
0 KB
55%
$12/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
268ms
168 KB
42%
$5/mo
Costly
www.gstatic.com
Other
Costly
Execution673ms
Transfer0 KB
Unused55%
Monthly Cost$12/mo
Google Tag Manager
Tag Manager
Costly
Execution268ms
Transfer168 KB
Unused42%
Monthly Cost$5/mo
These scripts may cost more than they're worth
www.gstatic.com adds 673ms and costs ~$12/month
Google Tag Manager adds 268ms and costs ~$5/month
48% of JavaScript execution time comes from third-party scripts.
Why this matters
Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.
Learn more ▾▴
Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.
Source: web.dev / HTTP Archive Web Almanac
www.gstatic.com takes 673ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
Why this matters
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
55% of www.gstatic.com'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.
Source: web.dev
Google Tag Manager takes 268ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
Why this matters
This script has high main-thread execution time — optimize hot paths or defer.
442 ms
2.7 s
3.1 s
3.5 s