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https://ahajournals.org

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
90
GRADE
A
FIX
2
REVIEW
1
PASS
12
INFO
2

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

Mobile Desktop
71
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.
96
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.

942 ms

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

3.19 s

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

1.03 s

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

0.006

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

942 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.

3.64 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
17
12 PASS 1 REVIEW 2 FIX
D
Third-Party Impact
Action
77% third-party, 0 ms blocking
FIX
77% third-party, 0 ms blocking
Warning::
Third-party code accounts for 77% of page weight (364.1 KiB of 471.0 KiB)
Info::
Third-party blocking time is low (0 ms)
23%
77%
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
C
JS Execution Cost
Action
1756ms total JS execution
REVIEW
1756ms total JS execution
Warning::
https://ahajournals.org/cdn-cgi/challenge-platform...: 1459ms CPU time
Info::
Unattributable: 187ms CPU time
Info::
https://ahajournals.org/: 110ms CPU time
Info::
Third-party scripts: 187ms (11% of total)

Main Thread Breakdown

Script Evaluation 78% Other 13% Garbage Collection 3%
ScriptTotalScriptingParse/CompileParty
https://ahajournals.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff0a8b7ac88e321459ms1374ms26ms1st
Unattributable187ms5ms0ms3rd
https://ahajournals.org/110ms15ms4ms1st
A+
Page Weight Budget
471 KB transferred, 19 requests
PASS
471 KB transferred, 19 requests
Info::
Page weighs 899 KB (471 KB transferred)
Info::
19 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
471 KB / 2.4 MB budget
471 KB transferred
19 requests
0.10 g CO2 per page load
Other 262.0 KiB 56%
JavaScript 98.0 KiB 21%
HTML 95.3 KiB 20%
Images 9.4 KiB 2%
Other 6.2 KiB 1%
Other 0 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 9 KB
0 oversized -0 KB
3 legacy format
0 missing dimensions CLS risk
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://ahajournals.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff0a8b7ac88e3274 KB—✓1st
https://static.cloudflareinsights.com/beacon.min.js/vcd15cbe7772f49c399c6a5babf22c12417176891760157 KB—✓3rd
blob:https://ahajournals.org/a08d3cc2-d95d-4fa8-9065-54feca40e1850 KB—✓3rd
https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicit17 KB—✓3rd
blob:https://ahajournals.org/5a74ed2d-e85c-4bcb-a8ac-b4893e11bb13-0 KB—✓3rd
blob:https://challenges.cloudflare.com/5d25100a-0560-4a36-9dc8-44d8b8dc372a0 KB—✓3rd
blob:https://challenges.cloudflare.com/db7d6f83-6742-492c-ae8e-e96c6e2eac40-0 KB—✓3rd
blob:https://challenges.cloudflare.com/db7d6f83-6742-492c-ae8e-e96c6e2eac40-0 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 · 471 KB · 0 KB savings available
PASS
19 resources · 471 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 471 KB
Warning::
12 third-party resources (77% of weight)
Info::
1 resources over 200KB
19 resources · 471.0 KiB · 12 third-party Within 1MB page-weight target
Other 56% · 262.1 KiB
Document 22% · 101.5 KiB
JavaScript 21% · 98.0 KiB
Image 2% · 9.4 KiB
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
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 1282ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 942 ms LCP 3.2 shttps://ahajournals.org// https://ahajournals.org/ — 307 — 65 B — 28 ms — http/1.1https://ahajournals.org// https://ahajournals.org/ — 403 — 5.6 KiB — 11 ms — h2https://ahajournals.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff0a8b7ac88e32/cdn-cgi/challenge-platform/h/b/orc... https://ahajournals.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff0a8b7ac88e32 — 200 — 73.8 KiB — 21 ms — h3https://static.cloudflareinsights.com/beacon.min.js/vcd15cbe7772f49c399c6a5babf22c1241717689176015static.cloudflareinsights.com/beaco... https://static.cloudflareinsights.com/beacon.min.js/vcd15cbe7772f49c399c6a5babf22c1241717689176015 — 200 — 6.9 KiB — 33 ms — h2blob:https://ahajournals.org/a08d3cc2-d95d-4fa8-9065-54feca40e185ahajournals.org/a08d3cc2-d95d-4fa8-... blob:https://ahajournals.org/a08d3cc2-d95d-4fa8-9065-54feca40e185 — -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 — 21 ms — h3https://ahajournals.org/favicon.ico/favicon.ico https://ahajournals.org/favicon.ico — 403 — 7.5 KiB — 13 ms — h3https://ahajournals.org/cdn-cgi/rum?/cdn-cgi/rum? https://ahajournals.org/cdn-cgi/rum? — 204 — 141 B — 14 ms — h3https://ahajournals.org/favicon.ico/favicon.ico https://ahajournals.org/favicon.ico — 403 — 6.1 KiB — 14 ms — h3https://ahajournals.org/cdn-cgi/challenge-platform/h/b/flow/ov1/2861708471:1776798608:ErqmkTBsxeuPEUEQ-nj3Qg5gifcpzcridMS7hc7f-HQ/9eff0a8b7ac88e32/Kn05IpVMhXYrcrEWsRUFe0vaQcENtR9i8V0Gf4PDs20-1776802321-1.2.1.1-HdzFCG9lSuYjJXE4Lqdzm2p1WGdOrIunkq7EvHe31iUp0NCEBznIG7rye0zh3HDS/cdn-cgi/challenge-platform/h/b/flo... https://ahajournals.org/cdn-cgi/challenge-platform/h/b/flow/ov1/2861708471:1776798608:ErqmkTBsxeuPEUEQ-nj3Qg5gifcpzcridMS7hc7f-HQ/9eff0a8b7ac88e32/Kn05IpVMhXYrcrEWsRUFe0vaQcENtR9i8V0Gf4PDs20-1776802321-1.2.1.1-HdzFCG9lSuYjJXE4Lqdzm2p1WGdOrIunkq7EvHe31iUp0NCEBznIG7rye0zh3HDS — 200 — 13.5 KiB — 30 ms — h3blob:https://ahajournals.org/5a74ed2d-e85c-4bcb-a8ac-b4893e11bb13ahajournals.org/5a74ed2d-e85c-4bcb-... blob:https://ahajournals.org/5a74ed2d-e85c-4bcb-a8ac-b4893e11bb13 — 200 — -1 B — 34 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/turnstile/f/ov2/av0/rch/oyttw/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/oyttw/0x4AAAAAAAAjq6WYeRDKmebM/light/fbE/new/normal?lang=auto — 200 — 89.7 KiB — 25 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 — 6 ms — h3blob:https://challenges.cloudflare.com/5d25100a-0560-4a36-9dc8-44d8b8dc372achallenges.cloudflare.com/5d25100a-... blob:https://challenges.cloudflare.com/5d25100a-0560-4a36-9dc8-44d8b8dc372a — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff0a8dda1293a3/ck.f2FE73cnNjbh0HD36Elcc.lwHGKcsFQsnkaKP_Bw-1776802321-1.2.1.1-VlxgB1_qJOhRaQ7I7w7VhqZEWyuj.JG9jUhBBtAxjv.1PAymn9HHf4ZamZpQ9FWIchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff0a8dda1293a3/ck.f2FE73cnNjbh0HD36Elcc.lwHGKcsFQsnkaKP_Bw-1776802321-1.2.1.1-VlxgB1_qJOhRaQ7I7w7VhqZEWyuj.JG9jUhBBtAxjv.1PAymn9HHf4ZamZpQ9FWI — 200 — 248.4 KiB — 108 ms — h3blob:https://challenges.cloudflare.com/db7d6f83-6742-492c-ae8e-e96c6e2eac40challenges.cloudflare.com/db7d6f83-... blob:https://challenges.cloudflare.com/db7d6f83-6742-492c-ae8e-e96c6e2eac40 — 200 — -1 B — 100 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/d/9eff0a8dda1293a3/1776802321899/ndTuepZ-CAcx40Xchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/d/9eff0a8dda1293a3/1776802321899/ndTuepZ-CAcx40X — 200 — 1.6 KiB — 6 ms — h3blob:https://challenges.cloudflare.com/db7d6f83-6742-492c-ae8e-e96c6e2eac40challenges.cloudflare.com/db7d6f83-... blob:https://challenges.cloudflare.com/db7d6f83-6742-492c-ae8e-e96c6e2eac40 — 200 — -1 B — 16 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/pat/9eff0a8dda1293a3/1776802321899/17179f994ab46c70d78daa70996cbe5c39b4ca1240ebfeb2202f211e7a857798/UnvyHEvN9HfGItgchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/pat/9eff0a8dda1293a3/1776802321899/17179f994ab46c70d78daa70996cbe5c39b4ca1240ebfeb2202f211e7a857798/UnvyHEvN9HfGItg — -1 — 0 B — 0 ms —
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
11% of JavaScript execution is third-party
First-party Third-party 187ms · 0KB · $2/mo
Unattributable
Other
Optional
Execution 187ms
Transfer 0 KB
Monthly Cost $2/mo

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.

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