Performance

· 23 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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

Mobile Desktop

Performance

100

Accessibility

100

Best Practices

SEO

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

569 ms

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

1.05 s

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

7 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.

780 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.

1.19 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

12 PASS 6 REVIEW 1 FIX

HTTP Caching

Action

no-store (uncacheable)

FIX

no-store (uncacheable)

Cache-Control: no-store prevents all caching

Intentional for dynamic content, but increases server load for every page view.

Got: private, no-cache, no-store, max-age=0, must-revalidate

No ETag or Last-Modified header

Conditional requests (304 Not Modified) are not possible without validators.

Cache-Control

private, no-cache, no-store, max-age=0, must-revalidate

Directive	Value	Meaning
private	—	Only browser cache, not CDN/proxy
no-cache	—	Cache but always revalidate first
no-store	—	Never cache this response
max-age	0	Cache for 0 seconds
must-revalidate	—	Must recheck with server after expiry

JS Execution Cost

Action

1494ms total JS execution

REVIEW

1494ms total JS execution

Unattributable: 419ms CPU time

https://localxlist.org/: 363ms CPU time

https://localxlist.org/_next/static/chunks/67c9d06...: 358ms CPU time

https://localxlist.org/_next/static/chunks/961311c...: 270ms CPU time

https://www.googletagmanager.com/gtag/js?id=G-KEWL...: 84ms CPU time

Third-party scripts: 84ms (6% of total)

Main Thread Breakdown

Script Evaluation 50% Other 26% Style & Layout 15% Rendering 4%

Script	Total	Scripting	Parse/Compile	Party
Unattributable	419ms	144ms	0ms	1st
https://localxlist.org/	363ms	8ms	6ms	1st
https://localxlist.org/_next/static/chunks/67c9d06fa8700707.js	358ms	278ms	3ms	1st
https://localxlist.org/_next/static/chunks/961311cbebbffb6d.js	270ms	252ms	6ms	1st
https://www.googletagmanager.com/gtag/js?id=G-KEWLXSC3R0	84ms	69ms	13ms	3rd

JS Bundles

19 scripts, 96 KB unused

REVIEW

19 scripts, 96 KB unused

https://www.googletagmanager.com/gtag/js?id=G-KEWL...: 70 KB unused (42%)

Consider code splitting or tree shaking to reduce unused code.

https://localxlist.org/_next/static/chunks/961311c...: 26 KB unused (32%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 96 KB

96 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.googletagmanager.com/gtag/js?id=G-KEWLXSC3R0	166 KB	70 KB (42%)	✓	3rd
https://localxlist.org/_next/static/chunks/961311cbebbffb6d.js	81 KB	26 KB (32%)	✓	1st
https://localxlist.org/_next/static/chunks/4b188ae602b9c4db.js	21 KB	—	✓	1st
https://localxlist.org/_next/static/chunks/744634c9afe0570c.js	22 KB	—	✓	1st
https://localxlist.org/_next/static/chunks/ede8a4b7a28a7a18.js	10 KB	—	✓	1st
https://localxlist.org/_next/static/chunks/797fcb0710da3be2.js	8 KB	—	✓	1st
https://localxlist.org/_next/static/chunks/turbopack-0f2881c0c5767128.js	5 KB	—	✓	1st
https://localxlist.org/_next/static/chunks/f249787193ec3d93.js	5 KB	—	✓	1st
https://localxlist.org/_next/static/chunks/102a67e358ac219f.js	2 KB	—	✓	1st
https://localxlist.org/_next/static/chunks/f7aec44ebff1872f.js	10 KB	—	✓	1st

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

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

HTTP/3 (QUIC)

HTTP/3 not advertised

REVIEW

HTTP/3 not advertised

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.

Compression Algorithm

Main response uses gzip; brotli would be ~20% smaller

REVIEW

Main response uses gzip; brotli would be ~20% smaller

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.

Server-Timing Observability

No Server-Timing header found

REVIEW

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.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

Page Weight Budget

813 KB transferred, 247 requests

PASS

813 KB transferred, 247 requests

Page weighs 2.1 MB (813 KB transferred)

247 HTTP requests — consider bundling or reducing

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Estimated 0.17 g CO2 per page load

813 KB transferred

247 requests

0.17 g CO2 per page load

JavaScript 402.3 KiB 50%

Other 270.4 KiB 33%

HTML 45.8 KiB 6%

Fonts 43.3 KiB 5%

CSS 31.7 KiB 4%

Images 16.5 KiB 2%

Other 1.9 KiB 0%

Other 548 B 0%

Other 0 B 0%

0 2.4 MB 4.9 MB

Under budget

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

Third-Party Impact

21% third-party, 0 ms blocking

PASS

21% third-party, 0 ms blocking

Third-party code accounts for 21% of page weight (170.2 KiB of 812.5 KiB)

Third-party blocking time is low (0 ms)

79%

21%

First-party Third-party

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

Image Optimization

17 images, 0 KB saveable

PASS

17 images, 0 KB saveable

All images are well-optimized

17 images 16 KB

0 oversized -0 KB

0 legacy format

0 missing dimensions CLS risk

A+

Font Loading

3 fonts (43 KB)

PASS

3 fonts (43 KB)

3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

43 KB total

Render-blocking

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

1bc7fc94203521e3-s.p.88... woff2 swap

Size 15 KB

Load time 201 ms

Start 366 ms

Risk FOUT — text flashes from fallback to web font

216579b50e548914-s.p.a1... woff2 swap

Size 14 KB

Load time 142 ms

Start 367 ms

Risk FOUT — text flashes from fallback to web font

3df2de83712245dd-s.p.b8... woff2 swap

Size 14 KB

Load time 164 ms

Start 368 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+

Resource Caching

All resources properly cached

PASS

All resources properly cached

No caching issues found

All static resources have appropriate caching headers.

A+

Critical Rendering Path

No render-blocking resources

PASS

No render-blocking resources

No render-blocking resources detected

A+

Resource Hints

No optimization needed

PASS

No optimization needed

No resource hint issues

A+

LCP Image Preload

LCP preload audit not available

PASS

LCP preload audit not available

LCP image preload audit not available for this scan

A+

Main HTML Cache-Control

Main HTML uses no-store -- correct for sensitive/dynamic content

PASS

Main HTML uses no-store -- correct for sensitive/dynamic content

Got: private, no-cache, no-store, max-age=0, must-revalidate

A+

Server Response Intelligence

2 server-response signal(s) detected

PASS

2 server-response signal(s) detected

`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).

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

247 resources · 813 KB · 96 KB savings available

PASS

247 resources · 813 KB · 96 KB savings available

Within 1MB page-weight target

Got: 813 KB

~96 KB of savings available

7 third-party resources (21% of weight)

247 resources · 812.5 KiB · 7 third-party Within 1MB page-weight target

JavaScript 50% · 402.3 KiB

Other 33% · 271.0 KiB

Document 6% · 45.8 KiB

Font 5% · 43.3 KiB

CSS 4% · 31.7 KiB

Image 2% · 18.4 KiB

~95.9 KiB of savings available

Remove unused JavaScript: 95.9 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

247 resources			812.5 KiB

Network Waterfall

247 requests over 7061ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Third-Party Script Cost

Per-script blocking time, transfer cost, and cache headers

INFO

6% of JavaScript execution is third-party

First-party Third-party 84ms · 166KB · $1/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
Google Tag Manager www.googletagmanager.com	Tag Manager	84ms	166 KB	42%	$1/mo	Optional

Google Tag Manager

Tag Manager

Optional

Execution 84ms

Transfer 166 KB

Unused 42%

Monthly Cost $1/mo

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 (2026-07-20 — 2026-08-16)

LCP (p75)

2976 ms

67% good

INP (p75)

136 ms

86% good

CLS (p75)

0.010

95% good

FCP (p75)

2965 ms

TTFB (p75)

1694 ms

Image Optimization

26 images, 9 KB total, 0 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

9 KB

15 missing lazy loading

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.