Performance

· 16 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.

3.81 s

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

3.97 s

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

960 ms

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

0.014

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

3.81 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.

6.29 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

8 PASS 5 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, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0

No ETag or Last-Modified header

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

Cache-Control

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

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

Page Weight Budget

1.1 MB transferred, 28 requests

REVIEW

1.1 MB transferred, 28 requests

Page weighs 1.8 MB (1.1 MB transferred)

28 HTTP requests

Estimated 0.22 g CO2 per page load

1.1 MB transferred

28 requests

0.22 g CO2 per page load

HTML 611.3 KiB 56%

Other 292.3 KiB 27%

JavaScript 88.0 KiB 8%

Fonts 67.7 KiB 6%

Images 35.8 KiB 3%

Other 1.7 KiB 0%

Other 74 B 0%

Other 71 B 0%

0 2.4 MB 4.9 MB

Under budget

Third-Party Impact

45% third-party, 0 ms blocking

REVIEW

45% third-party, 0 ms blocking

Third-party code accounts for 45% of page weight (494.5 KiB of 1.1 MiB)

Third-party blocking time is low (0 ms)

55%

45%

First-party Third-party

Image Optimization

6 images, 0 KB saveable

REVIEW

6 images, 0 KB saveable

All images are well-optimized

6 images 36 KB

0 oversized -0 KB

4 legacy format

0 missing dimensions CLS risk

JS Execution Cost

Action

1892ms total JS execution

REVIEW

1892ms total JS execution

https://www.sciencedirect.com/cdn-cgi/challenge-pl...: 1167ms CPU time

Unattributable: 418ms CPU time

https://www.sciencedirect.com/: 307ms CPU time

Third-party scripts: 418ms (22% of total)

Main Thread Breakdown

Script Evaluation 61% Other 24% Parse HTML & CSS 6% Style & Layout 5%

Script	Total	Scripting	Parse/Compile	Party
https://www.sciencedirect.com/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9e8ba4100ff603bd	1167ms	1108ms	23ms	1st
Unattributable	418ms	5ms	0ms	3rd
https://www.sciencedirect.com/	307ms	31ms	5ms	1st

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 (68 KB)

PASS

2 fonts (68 KB)

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

Web fonts

68 KB total

Render-blocking

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

octet-stream;base64,d09... unknown swap

Size 34 KB

Load time 0 ms

Start 0 ms

Risk FOUT — text flashes from fallback to web font

octet-stream;base64,d09... unknown swap

Size 34 KB

Load time 0 ms

Start 0 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)

Fixing the unchecked items could save ~20 KB and ~40 ms

A+

JS Bundles

11 scripts, 0 KB unused

PASS

11 scripts, 0 KB unused

0 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.sciencedirect.com/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9e8ba4100ff603bd	71 KB	—	✓	1st
blob:https://www.sciencedirect.com/bd6b0d5a-452a-4e82-8f82-620f16d2152a	0 KB	—	✓	3rd
https://challenges.cloudflare.com/turnstile/v0/b/625261456364/api.js?onload=OBvX9&render=explicit	17 KB	—	✓	3rd
blob:https://www.sciencedirect.com/4493cda0-89a5-4e93-994a-dff57fa3a650	-0 KB	—	✓	3rd
blob:https://challenges.cloudflare.com/682354ec-2f87-4009-9cf5-400fc78c9309	0 KB	—	✓	3rd
blob:https://challenges.cloudflare.com/950d06a3-75e0-465e-87dd-c629318433a2	-0 KB	—	✓	3rd
blob:https://challenges.cloudflare.com/950d06a3-75e0-465e-87dd-c629318433a2	-0 KB	—	✓	3rd
blob:https://challenges.cloudflare.com/950d06a3-75e0-465e-87dd-c629318433a2	-0 KB	—	✓	3rd
blob:https://challenges.cloudflare.com/950d06a3-75e0-465e-87dd-c629318433a2	-0 KB	—	✓	3rd
blob:https://challenges.cloudflare.com/950d06a3-75e0-465e-87dd-c629318433a2	0 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

1 hints, 0 missing preconnects

PASS

1 hints, 0 missing preconnects

Page uses 1 resource hint(s)

Current Resource Hints

preconnect

—

preload

dns-prefetch

—

prefetch

—

1 resource hints configured

A+

Render-Blocking Resources

No render-blocking resources detected

PASS

No render-blocking resources detected

No render-blocking resources detected in <head>

A+

Third-Party Resources

No third-party resources detected

PASS

No third-party resources detected

Network Waterfall

28 requests over 0ms

INFO

Performance analysis not available for this result.

Third-Party Script Cost

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

INFO

22% of JavaScript execution is third-party

First-party Third-party 418ms · 0KB · $6/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
Unattributable Unattributable	Other	418ms	0 KB	—	$6/mo	Costly

Unattributable

Other

Costly

Execution 418ms

Transfer 0 KB

Monthly Cost $6/mo

These scripts may cost more than they're worth

Unattributable adds 418ms and costs ~$6/month

Unattributable takes 418ms 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.