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https://news.ycombinator.com

Performance

· 18 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
98
GRADE
A+
FIX
0
REVIEW
2
PASS
13
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.
52
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
75
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.

857 ms

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

934 ms

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

27 ms

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

0.000

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

1.37 s

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

934 ms

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
18
13 PASS 2 REVIEW
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
private; max-age=0
REVIEW
private; max-age=0
Info::
Cache-Control header is set
Got: private; max-age=0
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

private; max-age=0

DirectiveValueMeaning
private; max-age0
A+
Page Weight Budget
11 KB transferred, 7 requests
PASS
11 KB transferred, 7 requests
Info::
Page weighs 47 KB (11 KB transferred)
Info::
7 HTTP requests
Info::
Estimated 0.00 g CO2 per page load
11 KB / 2.4 MB budget
11 KB transferred
7 requests
0.00 g CO2 per page load
HTML 6.2 KiB 55%
JavaScript 2.1 KiB 19%
CSS 2.0 KiB 17%
Images 1.0 KiB 9%
Other 0 B 0%
0 2.4 MB 4.9 MB
Under budget
A+
Third-Party Impact
No third-party resources
PASS
No third-party resources
Info::
No third-party resources detected
No third-party resources detected — all resources are first-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
3 images, 0 KB saveable
PASS
3 images, 0 KB saveable
Info::
All images are well-optimized
3 images 1 KB
0 oversized -0 KB
3 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
455ms total JS execution
PASS
455ms total JS execution
Info::
Unattributable: 230ms CPU time
Info::
https://news.ycombinator.com/: 225ms CPU time
Warning::
Third-party scripts: 230ms (50% of total)

Main Thread Breakdown

Other 53% Style & Layout 26% Rendering 11% Script Evaluation 6% Parse HTML & CSS 5%
ScriptTotalScriptingParse/CompileParty
Unattributable230ms10ms0ms3rd
https://news.ycombinator.com/225ms7ms1ms1st
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
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://news.ycombinator.com/hn.js?qhau9sYt9MldNVV0J6qe2 KB—✓1st
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+
Page Weight Inventory
7 resources · 11 KB · 0 KB savings available
PASS
7 resources · 11 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 11 KB
7 resources · 11.3 KiB · 0 third-party Within 1MB page-weight target
Document 55% · 6.2 KiB
JavaScript 19% · 2.1 KiB
CSS 17% · 2.0 KiB
Image 9% · 1.0 KiB
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
Network Waterfall
7 requests over 809ms
INFO
0 ms 200 ms 400 ms 600 ms 800 ms FCP 857 ms LCP 934 mshttps://news.ycombinator.com// https://news.ycombinator.com/ — 200 — 6.2 KiB — 455 ms — h2https://news.ycombinator.com/news.css?qhau9sYt9MldNVV0J6qe/news.css?qhau9sYt9MldNVV0J6qe https://news.ycombinator.com/news.css?qhau9sYt9MldNVV0J6qe — 200 — 2.0 KiB — 153 ms — h2https://news.ycombinator.com/y18.svg/y18.svg https://news.ycombinator.com/y18.svg — 200 — 512 B — 155 ms — h2https://news.ycombinator.com/hn.js?qhau9sYt9MldNVV0J6qe/hn.js?qhau9sYt9MldNVV0J6qe https://news.ycombinator.com/hn.js?qhau9sYt9MldNVV0J6qe — 200 — 2.1 KiB — 156 ms — h2https://news.ycombinator.com/s.gif/s.gif https://news.ycombinator.com/s.gif — 200 — 234 B — 156 ms — h2https://news.ycombinator.com/triangle.svg/triangle.svg https://news.ycombinator.com/triangle.svg — 200 — 328 B — 152 ms — h2https://news.ycombinator.com/y18.svg/y18.svg https://news.ycombinator.com/y18.svg — 200 — 0 B — 3 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
50% of JavaScript execution is third-party
First-party Third-party 230ms · 0KB · €2/mo
Unattributable
Other
Costly
Execution 230ms
Transfer 0 KB
Monthly Cost €2/mo

These scripts may cost more than they're worth

  • Unattributable adds 230ms and costs ~€2/month

50% 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

Unattributable takes 230ms 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

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 (2026-03-25 — 2026-04-21)

LCP (p75)

487 ms

99% good

INP (p75)

45 ms

100% good

CLS (p75)

0.000

100% good

FCP (p75)

491 ms

TTFB (p75)

562 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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