Performance

· 15 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.

2.42 s

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

4.17 s

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

422 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.

5.37 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.

14.62 s

Page Load Progression

1.5 s

3.1 s

4.6 s

6.2 s

7.7 s

9.3 s

10.8 s

12.4 s

Checks

6 PASS 2 REVIEW 5 FIX

Page Weight Budget

Action

23.9 MB transferred, 615 requests

FIX

23.9 MB transferred, 615 requests

Page weighs 43.2 MB (23.9 MB transferred)

Images are 3.8 MB — compress or use modern formats

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

Got: 3.8 MB

JavaScript is 1.4 MB — consider code splitting or lazy loading

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Got: 1.4 MB

615 HTTP requests — consider bundling or reducing

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

Estimated 5.0 g CO2 per page load

23.9 MB transferred

615 requests

5.0 g CO2 per page load

Other 10.7 MiB 45%

Other 7.8 MiB 33%

Images 3.8 MiB 16%

JavaScript 1.4 MiB 6%

CSS 48.0 KiB 0%

HTML 44.1 KiB 0%

Fonts 40.8 KiB 0%

Other 1.9 KiB 0%

Other 806 B 0%

0 2.4 MB 4.9 MB

Over budget

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

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

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

Action

100% third-party, 0 ms blocking

FIX

100% third-party, 0 ms blocking

Third-party code accounts for 100% of page weight (23.9 MiB of 23.9 MiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

JS Execution Cost

Action

2343ms total JS execution

FIX

2343ms total JS execution

https://www.xunlei.com/js/app.8471c94b.js: 1135ms CPU time

Unattributable: 907ms CPU time

https://www.xunlei.com/: 240ms CPU time

https://hm.baidu.com/hm.js?fc3993ee6315a64049f3b26...: 61ms CPU time

Third-party scripts: 2343ms (100% of total)

Main Thread Breakdown

Other 46% Script Evaluation 41% Style & Layout 7%

Script	Total	Scripting	Parse/Compile	Party
https://www.xunlei.com/js/app.8471c94b.js	1135ms	903ms	0ms	3rd
Unattributable	907ms	15ms	0ms	3rd
https://www.xunlei.com/	240ms	2ms	0ms	3rd
https://hm.baidu.com/hm.js?fc3993ee6315a64049f3b26b7073a986	61ms	46ms	4ms	3rd

JS Bundles

Action

6 scripts, 1019 KB unused

FIX

6 scripts, 1019 KB unused

https://www.xunlei.com/js/chunk-common.18ae7111.js: 920 KB unused (94%)

Consider code splitting or tree shaking to reduce unused code.

https://www.xunlei.com/js/vendor.7fe0b994.js: 99 KB unused (60%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 1019 KB

1019 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.xunlei.com/js/chunk-common.18ae7111.js	1268 KB	920 KB (94%)	✓	3rd
https://www.xunlei.com/js/vendor.7fe0b994.js	167 KB	99 KB (60%)	✓	3rd
https://hm.baidu.com/hm.js?fc3993ee6315a64049f3b26b7073a986	12 KB	—	✓	3rd
https://www.xunlei.com/fetch.js	3 KB	—	✓	3rd
https://www.xunlei.com/js/3.f88d207e.js	12 KB	—	✓	3rd
https://www.xunlei.com/js/app.8471c94b.js	4 KB	—	✓	3rd

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

Page Weight Inventory

Action

615 resources · 23.9 MB · 1019 KB savings available

FIX

615 resources · 23.9 MB · 1019 KB savings available

Page weight 22.9 MB over 1MB target

Got: 23.9 MB Expected: ≤ 1 MB

~1019 KB of savings available

614 third-party resources (100% of weight)

15 resources over 200KB

615 resources · 23.9 MiB · 614 third-party 22.9 MiB over 1MB target

Image 61% · 14.5 MiB

Media 33% · 7.8 MiB

JavaScript 6% · 1.4 MiB

CSS 0% · 48.0 KiB

Document 0% · 44.3 KiB

Font 0% · 40.8 KiB

Other 0% · 806 B

~1019.1 KiB of savings available

Remove unused JavaScript: 1019.1 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

615 resources			23.9 MiB

Image Optimization

585 images, 0 KB saveable

REVIEW

585 images, 0 KB saveable

All images are well-optimized

585 images 3.8 MB

0 oversized -0 KB

45 legacy format

0 missing dimensions CLS risk

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

Font Loading

2 fonts (41 KB)

PASS

2 fonts (41 KB)

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

Web fonts

41 KB total

Render-blocking

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

KFOlCnqEu92Fr1MmWUlfBBc... woff swap

Size 20 KB

Load time 183 ms

Start 6.3 s

Risk FOUT — text flashes from fallback to web font

Convert to woff2 for ~30% smaller file size

KFOmCnqEu92Fr1Mu4mxM.9b... woff swap

Size 20 KB

Load time 245 ms

Start 6.3 s

Risk FOUT — text flashes from fallback to web font

Convert to woff2 for ~30% smaller file size

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)

Fixing the unchecked items could save ~12 KB and ~24 ms

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

HTTP Caching

max-age=86400 (1 day)

PASS

max-age=86400 (1 day)

Cache-Control header is set

Got: max-age=86400

Effective TTL: 1 day (max-age=86400)

No ETag or Last-Modified header

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

Cache-Control

max-age=86400

Directive	Value	Meaning
max-age	86400	Cache for 1 day

Effective TTL: 86400 seconds

Network Waterfall

615 requests over 10076ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Third-Party Script Cost

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

INFO

100% of JavaScript execution is third-party

First-party Third-party 2343ms · 60KB · ¥116/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
www.xunlei.com www.xunlei.com	Other	1135ms	4 KB	—	¥56/mo	Costly
Unattributable Unattributable	Other	907ms	0 KB	—	¥45/mo	Costly
www.xunlei.com www.xunlei.com	Other	240ms	44 KB	—	¥12/mo	Costly
hm.baidu.com hm.baidu.com	Other	61ms	12 KB	—	¥3/mo	Optional

www.xunlei.com

Other

Costly

Execution 1135ms

Transfer 4 KB

Monthly Cost ¥56/mo

Unattributable

Other

Costly

Execution 907ms

Transfer 0 KB

Monthly Cost ¥45/mo

www.xunlei.com

Other

Costly

Execution 240ms

Transfer 44 KB

Monthly Cost ¥12/mo

hm.baidu.com

Other

Optional

Execution 61ms

Transfer 12 KB

Monthly Cost ¥3/mo

These scripts may cost more than they're worth

www.xunlei.com adds 1135ms and costs ~¥56/month
Unattributable adds 907ms and costs ~¥45/month
www.xunlei.com adds 240ms and costs ~¥12/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.

Learn more ▾

Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.

Source: web.dev

www.xunlei.com takes 1135ms 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

Unattributable takes 907ms 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

www.xunlei.com takes 240ms 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

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