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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
90
GRADE
A
FIX
2
REVIEW
0
PASS
11
INFO
1

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.
90
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
92
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
36
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.

272 ms

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

783 ms

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

52 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.

399 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.

783 ms

Page Load Progression

478 ms
956 ms
1.4 s
1.9 s
2.4 s
2.9 s
3.3 s
3.8 s
Checks
14
11 PASS 2 FIX
D
Third-Party Impact
Action
82% third-party, 0 ms blocking
FIX
82% third-party, 0 ms blocking
Warning::
Third-party code accounts for 82% of page weight (408.1 KiB of 498.8 KiB)
Info::
Third-party blocking time is low (0 ms)
18%
82%
First-party Third-party
D
HTTP Caching
Action
no-store (uncacheable)
FIX
no-store (uncacheable)
Info::
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
Info::
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

DirectiveValueMeaning
private—Only browser cache, not CDN/proxy
max-age0Cache 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-check0
pre-check0
A+
Page Weight Budget
499 KB transferred, 19 requests
PASS
499 KB transferred, 19 requests
Info::
Page weighs 897 KB (499 KB transferred)
Info::
19 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
499 KB / 2.4 MB budget
499 KB transferred
19 requests
0.10 g CO2 per page load
Other 308.2 KiB 62%
HTML 98.5 KiB 20%
JavaScript 89.8 KiB 18%
Other 1.7 KiB 0%
Images 581 B 0%
Other 58 B 0%
0 2.4 MB 4.9 MB
Under budget
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
2 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
436ms total JS execution
PASS
436ms total JS execution
Warning::
https://pnas.org/cdn-cgi/challenge-platform/h/b/or...: 436ms CPU time

Main Thread Breakdown

Script Evaluation 81% Other 10% Garbage Collection 4%
ScriptTotalScriptingParse/CompileParty
https://pnas.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9efea0536b957a81436ms410ms6ms1st
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
8 scripts, 0 KB unused
PASS
8 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://pnas.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9efea0536b957a8172 KB—✓1st
blob:https://pnas.org/90eb32f9-742b-4b48-b1b2-df94d4213cb90 KB—✓3rd
https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicit17 KB—✓3rd
blob:https://pnas.org/cce981f0-bc25-44ec-823a-084c0327f9d2-0 KB—✓3rd
blob:https://challenges.cloudflare.com/3970d608-a42d-422f-ab93-6a854cf173360 KB—✓3rd
blob:https://challenges.cloudflare.com/ee2a369e-8d12-4e1e-a64b-c256b2a9a88f-0 KB—✓3rd
blob:https://challenges.cloudflare.com/ee2a369e-8d12-4e1e-a64b-c256b2a9a88f-0 KB—✓3rd
blob:https://challenges.cloudflare.com/04d64d8c-94cd-4414-80af-055eb7485965-0 KB—✓3rd
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
19 resources · 499 KB · 0 KB savings available
PASS
19 resources · 499 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 499 KB
Warning::
13 third-party resources (82% of weight)
Info::
1 resources over 200KB
19 resources · 498.8 KiB · 13 third-party Within 1MB page-weight target
Other 62% · 310.0 KiB
Document 20% · 98.5 KiB
JavaScript 18% · 89.8 KiB
Image 0% · 581 B
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
19 requests over 3376ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 272 ms LCP 783 mshttps://pnas.org// https://pnas.org/ — 307 — 58 B — 25 ms — http/1.1https://pnas.org// https://pnas.org/ — 403 — 4.7 KiB — 8 ms — h3https://pnas.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9efea0536b957a81/cdn-cgi/challenge-platform/h/b/orc... https://pnas.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9efea0536b957a81 — 200 — 72.4 KiB — 21 ms — h3blob:https://pnas.org/90eb32f9-742b-4b48-b1b2-df94d4213cb9pnas.org/90eb32f9-742b-4b48-b1b2-df... blob:https://pnas.org/90eb32f9-742b-4b48-b1b2-df94d4213cb9 — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicitchallenges.cloudflare.com/turnstile... https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicit — 200 — 17.4 KiB — 26 ms — h3https://pnas.org/favicon.ico/favicon.ico https://pnas.org/favicon.ico — -1 — 0 B — 19 ms — https://pnas.org/favicon.ico/favicon.ico https://pnas.org/favicon.ico — -1 — 0 B — 5 ms — https://pnas.org/cdn-cgi/challenge-platform/h/b/flow/ov1/597893741:1776795215:vX6DMo7H36ToU6CK3GVGs0lXKjzgVqdLcuBarjY5DlI/9efea0536b957a81/hAwdTjzVocHeCXS9w.BVasKQRrEordt_BMloRIidyH8-1776797970-1.2.1.1-mRs8IAy6fE.Kjw7viCsuCWpnxEwQ2kslhmSQHxr.5T1mPbVcG7Uy5F0PQg7j50yJ/cdn-cgi/challenge-platform/h/b/flo... https://pnas.org/cdn-cgi/challenge-platform/h/b/flow/ov1/597893741:1776795215:vX6DMo7H36ToU6CK3GVGs0lXKjzgVqdLcuBarjY5DlI/9efea0536b957a81/hAwdTjzVocHeCXS9w.BVasKQRrEordt_BMloRIidyH8-1776797970-1.2.1.1-mRs8IAy6fE.Kjw7viCsuCWpnxEwQ2kslhmSQHxr.5T1mPbVcG7Uy5F0PQg7j50yJ — 200 — 13.5 KiB — 27 ms — h3blob:https://pnas.org/cce981f0-bc25-44ec-823a-084c0327f9d2pnas.org/cce981f0-bc25-44ec-823a-08... blob:https://pnas.org/cce981f0-bc25-44ec-823a-084c0327f9d2 — 200 — -1 B — 42 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/turnstile/f/ov2/av0/rch/8mivg/0x4AAAAAAAAjq6WYeRDKmebM/light/fbE/new/normal?lang=autochallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/turnstile/f/ov2/av0/rch/8mivg/0x4AAAAAAAAjq6WYeRDKmebM/light/fbE/new/normal?lang=auto — 200 — 93.7 KiB — 36 ms — h3https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/cmg/1challenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/cmg/1 — 200 — 208 B — 13 ms — h3blob:https://challenges.cloudflare.com/3970d608-a42d-422f-ab93-6a854cf17336challenges.cloudflare.com/3970d608-... blob:https://challenges.cloudflare.com/3970d608-a42d-422f-ab93-6a854cf17336 — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/2588405380:1776795216:AJWrEkDQ8dUubMe8zqJ3LDqGsZyer622-ACqEQQp-uI/9efea055bc014e6f/JloHVcuiGMkcTXRERG2AU17.lk8L4rWXMw9oJ17D78Q-1776797970-1.2.1.1-ohuaxyfZ3juPn7yD6GfarfBKzTmnp30lrhT8eRgADfxk4Egk11wPUT4n1sr_rMVIchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/2588405380:1776795216:AJWrEkDQ8dUubMe8zqJ3LDqGsZyer622-ACqEQQp-uI/9efea055bc014e6f/JloHVcuiGMkcTXRERG2AU17.lk8L4rWXMw9oJ17D78Q-1776797970-1.2.1.1-ohuaxyfZ3juPn7yD6GfarfBKzTmnp30lrhT8eRgADfxk4Egk11wPUT4n1sr_rMVI — 200 — 271.9 KiB — 108 ms — h3blob:https://challenges.cloudflare.com/ee2a369e-8d12-4e1e-a64b-c256b2a9a88fchallenges.cloudflare.com/ee2a369e-... blob:https://challenges.cloudflare.com/ee2a369e-8d12-4e1e-a64b-c256b2a9a88f — 200 — -1 B — 97 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/pat/9efea055bc014e6f/1776797971175/b928758b925f31fc132e5ec89ef4f80adc2aa4df0d8bd375641fbb01cd4f82f2/RtoeIGEBD4mjn9Hchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/pat/9efea055bc014e6f/1776797971175/b928758b925f31fc132e5ec89ef4f80adc2aa4df0d8bd375641fbb01cd4f82f2/RtoeIGEBD4mjn9H — 401 — 1.7 KiB — 7 ms — h3blob:https://challenges.cloudflare.com/ee2a369e-8d12-4e1e-a64b-c256b2a9a88fchallenges.cloudflare.com/ee2a369e-... blob:https://challenges.cloudflare.com/ee2a369e-8d12-4e1e-a64b-c256b2a9a88f — 200 — -1 B — 23 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/d/9efea055bc014e6f/1776797971176/Q4h7Vm2AhbFlJd6challenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/d/9efea055bc014e6f/1776797971176/Q4h7Vm2AhbFlJd6 — 200 — 373 B — 6 ms — h3https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/2588405380:1776795216:AJWrEkDQ8dUubMe8zqJ3LDqGsZyer622-ACqEQQp-uI/9efea055bc014e6f/JloHVcuiGMkcTXRERG2AU17.lk8L4rWXMw9oJ17D78Q-1776797970-1.2.1.1-ohuaxyfZ3juPn7yD6GfarfBKzTmnp30lrhT8eRgADfxk4Egk11wPUT4n1sr_rMVIchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/2588405380:1776795216:AJWrEkDQ8dUubMe8zqJ3LDqGsZyer622-ACqEQQp-uI/9efea055bc014e6f/JloHVcuiGMkcTXRERG2AU17.lk8L4rWXMw9oJ17D78Q-1776797970-1.2.1.1-ohuaxyfZ3juPn7yD6GfarfBKzTmnp30lrhT8eRgADfxk4Egk11wPUT4n1sr_rMVI — 200 — 22.8 KiB — 38 ms — h3blob:https://challenges.cloudflare.com/04d64d8c-94cd-4414-80af-055eb7485965challenges.cloudflare.com/04d64d8c-... blob:https://challenges.cloudflare.com/04d64d8c-94cd-4414-80af-055eb7485965 — 200 — -1 B — 22 ms — blob
HTML JavaScript CSS Images Fonts XHR/Fetch Other
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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