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

Accessibility

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.

966 ms

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

2.24 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.

0.421

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

1.26 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.

2.24 s

Page Load Progression

395 ms

790 ms

1.2 s

1.6 s

2.0 s

2.4 s

2.8 s

3.2 s

Checks

11 PASS 6 REVIEW 2 FIX

Page Weight Budget

Action

2.3 MB transferred, 26 requests

FIX

2.3 MB transferred, 26 requests

Page weighs 2.4 MB (2.3 MB transferred)

Images are 2.3 MB — compress or use modern formats

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Got: 2.3 MB

26 HTTP requests

Estimated 0.49 g CO2 per page load

2.3 MB transferred

26 requests

0.49 g CO2 per page load

Images 2.3 MiB 98%

JavaScript 35.9 KiB 1%

HTML 9.4 KiB 0%

CSS 7.3 KiB 0%

Other 6.2 KiB 0%

Other 220 B 0%

0 2.4 MB 4.9 MB

Approaching limit

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

HTTP Caching

Action

No cache headers

FIX

No cache headers

No Cache-Control header found

Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

Image Optimization

17 images, 0 KB saveable

REVIEW

17 images, 0 KB saveable

All images are well-optimized

17 images 2.3 MB

0 oversized -0 KB

17 legacy format

0 missing dimensions CLS risk

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.

Document Compression

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

REVIEW

Document 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.

Main HTML Cache-Control

No Cache-Control header on main HTML response

REVIEW

No Cache-Control header on main HTML response

Main HTML response has no Cache-Control header

Without an explicit Cache-Control, browsers fall back to heuristic caching (~10% of Last-Modified age). Set `Cache-Control: no-cache` or `max-age=300` for HTML to control freshness explicitly -- prevents stale auth state and SPA shell drift.

Page Weight Inventory

Action

26 resources · 2.3 MB · 0 KB savings available

REVIEW

26 resources · 2.3 MB · 0 KB savings available

Page weight 2.3 MB exceeds 1 MB target by 1.3 MB

Got: 2.3 MB Expected: ≤ 1 MB

1 third-party resources (1% of weight)

6 resources over 200KB

26 resources · 2.3 MiB · 1 third-party 1.3 MiB over 1MB target

Image 98% · 2.3 MiB

JavaScript 1% · 35.9 KiB

Document 0% · 9.4 KiB

CSS 0% · 7.3 KiB

Other 0% · 6.4 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

26 resources			2.3 MiB

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

A+

Third-Party Impact

1% third-party, 0 ms blocking

PASS

1% third-party, 0 ms blocking

Third-party code accounts for 1% of page weight (13.2 KiB of 2.3 MiB)

Third-party blocking time is low (0 ms)

99%

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+

JS Execution Cost

225ms total JS execution

PASS

225ms total JS execution

https://ai.zhailaoban.com/showcase: 158ms CPU time

Unattributable: 67ms CPU time

Main Thread Breakdown

Other 37% Style & Layout 36% Rendering 14% Script Evaluation 9%

Script	Total	Scripting	Parse/Compile	Party
https://ai.zhailaoban.com/showcase	158ms	7ms	1ms	1st
Unattributable	67ms	3ms	0ms	1st

A+

Font Loading

No web fonts (system fonts)

PASS

No web fonts (system fonts)

No web fonts loaded — system fonts are fastest

No web fonts loaded — system fonts are optimal.

JS Bundles

3 scripts, 0 KB unused

PASS

3 scripts, 0 KB unused

https://ai.zhailaoban.com/static/ai_support.js?v=2...: unminified — 3 KB could be saved

0 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://ai.zhailaoban.com/static/social_proof.js?v=1	4 KB	—	✓	1st
https://ai.zhailaoban.com/static/ai_support.js?v=20260927support4	19 KB	—	✗	1st
https://res.wx.qq.com/open/js/jweixin-1.6.0.js	13 KB	—	✓	3rd

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+

Server-Timing Observability

1 Server-Timing entries advertised

PASS

1 Server-Timing entries advertised

Server-Timing header advertises 1 timing entries

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.

Asset Compression

No text asset hosts to measure

INFO

No text asset hosts to measure

No third-party or subdomain host served enough text assets to measure

Asset compression is measured per host, from one HEAD request against a sampled resource. Pages that serve all their JS and CSS from the document's own origin are covered by the document compression check instead.

Network Waterfall

26 requests over 3313ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

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 (2026-09-05 — 2026-10-02)

LCP (p75)

1072 ms

90% good

INP (p75)

0 ms

0% good

CLS (p75)

0.000

0% good

FCP (p75)

643 ms

TTFB (p75)

357 ms

Image Optimization

37 images, 1101 KB total, 999 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

1101 KB

Oversized

Wasted

999 KB

36 missing dimensions 2 missing lazy loading

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