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https://440hz.app

Performance

· 26 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
98
GRADE
A+
FIX
0
REVIEW
2
PASS
21
INFO
3

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
100
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
87
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

962 ms

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

1.60 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

0 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.004

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

962 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

1.60 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
26
21 PASS 2 REVIEW
C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
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
HTTP Caching
public, max-age=0, must-revalidate
REVIEW
public, max-age=0, must-revalidate
Info::
Cache-Control header is set
Got: public, max-age=0, must-revalidate
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

public, max-age=0, must-revalidate

DirectiveValueMeaning
public—Any cache may store this response
max-age0Cache for 0 seconds
must-revalidate—Must recheck with server after expiry
A+
Page Weight Budget
75 KB transferred, 8 requests
PASS
75 KB transferred, 8 requests
Info::
Page weighs 117 KB (75 KB transferred)
Info::
8 HTTP requests
Info::
Estimated 0.02 g CO2 per page load
75 KB / 2.4 MB budget
75 KB transferred
8 requests
0.02 g CO2 per page load
Fonts 53.4 KiB 71%
JavaScript 10.7 KiB 14%
HTML 5.6 KiB 8%
CSS 3.6 KiB 5%
Other 952 B 1%
Other 453 B 1%
0 2.4 MB 4.9 MB
Under budget
A+
Third-Party Impact
14% third-party, 0 ms blocking
PASS
14% third-party, 0 ms blocking
Info::
Third-party code accounts for 14% of page weight (10.7 KiB of 74.7 KiB)
Info::
Third-party blocking time is low (0 ms)
86%
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
No images on this page
PASS
No images on this page
Info::
No images on this page
0 images 0 KB
0 oversized -0 KB
0 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
496ms total JS execution
PASS
496ms total JS execution
Warning::
https://440hz.app/: 273ms CPU time
Info::
Unattributable: 162ms CPU time
Info::
https://static.cloudflareinsights.com/beacon.min.j...: 61ms CPU time
Info::
Third-party scripts: 223ms (45% of total)

Main Thread Breakdown

Style & Layout 39% Other 37% Script Evaluation 12% Rendering 8%
ScriptTotalScriptingParse/CompileParty
https://440hz.app/273ms8ms2ms1st
Unattributable162ms7ms0ms3rd
https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312451661ms41ms5ms3rd
A+
Font Loading
2 fonts (53 KB)
PASS
2 fonts (53 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

53 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s FCP 962 ms LCP 1.6 shttps://440hz.app/assets/fonts/space-grotesk-latin.woff2space-grotesk-latin.woff2 https://440hz.app/assets/fonts/space-grotesk-latin.woff2 — 22.3 KiB — 30 ms — font-display: swaphttps://440hz.app/assets/fonts/jetbrains-mono-latin.woff2jetbrains-mono-latin.woff2 https://440hz.app/assets/fonts/jetbrains-mono-latin.woff2 — 31.1 KiB — 30 ms — font-display: swap
space-grotesk-latin.woff2 woff2 swap
Size 22 KB
Load time 30 ms
Start 129 ms
Risk FOUT — text flashes from fallback to web font
jetbrains-mono-latin.woff2 woff2 swap
Size 31 KB
Load time 30 ms
Start 129 ms
Risk FOUT — 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+
JS Bundles
1 scripts, 0 KB unused
PASS
1 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312451611 KB—✓3rd
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+
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+
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-Timing Observability
3 Server-Timing entries advertised
PASS
3 Server-Timing entries advertised
Info::
Server-Timing header advertises 3 timing entries
A+
Server Response Intelligence
1 server-response signal(s) detected
PASS
1 server-response signal(s) detected
Info::
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+
Page Weight Inventory
8 resources · 75 KB · 0 KB savings available
PASS
8 resources · 75 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 75 KB
Info::
1 third-party resources (14% of weight)
8 resources · 74.7 KiB · 1 third-party Within 1MB page-weight target
Font 71% · 53.4 KiB
JavaScript 14% · 10.7 KiB
Document 8% · 5.6 KiB
CSS 5% · 3.6 KiB
Image 1% · 952 B
Other 1% · 453 B
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
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
8 requests over 254ms
INFO
0 ms 500 ms 1.0 s 1.5 s FCP 962 ms LCP 1.6 shttps://440hz.app// https://440hz.app/ — 200 — 5.6 KiB — 44 ms — h3https://440hz.app/css/style.css/css/style.css https://440hz.app/css/style.css — 200 — 3.6 KiB — 19 ms — h3https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da1771523124516static.cloudflareinsights.com/beaco... https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da1771523124516 — 200 — 10.7 KiB — 24 ms — h2https://440hz.app/assets/fonts/space-grotesk-latin.woff2/assets/fonts/space-grotesk-latin.w... https://440hz.app/assets/fonts/space-grotesk-latin.woff2 — 200 — 22.3 KiB — 30 ms — h3https://440hz.app/assets/fonts/jetbrains-mono-latin.woff2/assets/fonts/jetbrains-mono-latin.... https://440hz.app/assets/fonts/jetbrains-mono-latin.woff2 — 200 — 31.1 KiB — 30 ms — h3https://440hz.app/cdn-cgi/rum?/cdn-cgi/rum? https://440hz.app/cdn-cgi/rum? — 204 — 453 B — 7 ms — h3https://440hz.app/assets/icons/icon.svg/assets/icons/icon.svg https://440hz.app/assets/icons/icon.svg — 200 — 473 B — 38 ms — h3https://440hz.app/assets/icons/favicon.ico/assets/icons/favicon.ico https://440hz.app/assets/icons/favicon.ico — 200 — 479 B — 18 ms — h3
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
45% of JavaScript execution is third-party
First-party Third-party 223ms · 11KB · €2/mo
Unattributable
Other
Optional
Execution 162ms
Transfer 0 KB
Monthly Cost €2/mo
static.cloudflareinsights.com
Other
Optional
Execution 61ms
Transfer 11 KB
Monthly Cost €1/mo

45% 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

How third-party costs are calculated

Real-User Performance (CrUX)
Field metrics from the Chrome User Experience Report
INFO

Chrome User Experience (CrUX)

Real-user metrics from the Chrome UX Report (2026-04-11 — 2026-05-08)

LCP (p75)

520 ms

98% good

INP (p75)

65 ms

92% good

CLS (p75)

0.000

96% good

FCP (p75)

475 ms

TTFB (p75)

215 ms

This origin passes Core Web Vitals assessment
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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