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https://ahajournals.org

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
90
GRADE
A
FIX
2
REVIEW
1
PASS
10
INFO
2

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

Mobile Desktop
99
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.

269 ms

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

824 ms

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

84 ms

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

0.001

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

461 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.

825 ms

Page Load Progression

500 ms
1.0 s
1.5 s
2.0 s
2.5 s
3.0 s
3.5 s
4.0 s
Checks
15
10 PASS 1 REVIEW 2 FIX
D
Third-Party Impact
Action
79% third-party, 0 ms blocking
FIX
79% third-party, 0 ms blocking
Warning::
Third-party code accounts for 79% of page weight (398.5 KiB of 502.5 KiB)
Info::
Third-party blocking time is low (0 ms)
21%
79%
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
B
JS Execution Cost
548ms total JS execution
REVIEW
548ms total JS execution
Warning::
https://ahajournals.org/cdn-cgi/challenge-platform...: 495ms CPU time
Info::
Unattributable: 53ms CPU time
Info::
Third-party scripts: 53ms (10% of total)

Main Thread Breakdown

Script Evaluation 83% Other 10%
ScriptTotalScriptingParse/CompileParty
https://ahajournals.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff0ae56bacd283495ms477ms6ms1st
Unattributable53ms2ms0ms3rd
A+
Page Weight Budget
503 KB transferred, 24 requests
PASS
503 KB transferred, 24 requests
Info::
Page weighs 936 KB (503 KB transferred)
Info::
24 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
503 KB / 2.4 MB budget
503 KB transferred
24 requests
0.10 g CO2 per page load
Other 293.9 KiB 58%
HTML 95.6 KiB 19%
JavaScript 95.2 KiB 19%
Images 10.0 KiB 2%
Other 6.2 KiB 1%
Other 1.7 KiB 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 10 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
12 scripts, 0 KB unused
PASS
12 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=9eff0ae56bacd28371 KB—✓1st
https://static.cloudflareinsights.com/beacon.min.js/vcd15cbe7772f49c399c6a5babf22c12417176891760157 KB—✓3rd
blob:https://ahajournals.org/f49ea1f3-104d-4d86-9d07-1b4fcff3cabc0 KB—✓3rd
https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicit17 KB—✓3rd
blob:https://ahajournals.org/7605feb1-4f10-4d36-852d-82bee8515bc2-0 KB—✓3rd
blob:https://challenges.cloudflare.com/9395040f-e14d-4f07-8fb0-ef595752b0dc0 KB—✓3rd
blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c-0 KB—✓3rd
blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c-0 KB—✓3rd
blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c-0 KB—✓3rd
blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c-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
24 resources · 503 KB · 0 KB savings available
PASS
24 resources · 503 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 503 KB
Warning::
17 third-party resources (79% of weight)
Info::
1 resources over 200KB
24 resources · 502.5 KiB · 17 third-party Within 1MB page-weight target
Other 59% · 295.6 KiB
Document 20% · 101.7 KiB
JavaScript 19% · 95.2 KiB
Image 2% · 10.0 KiB
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
24 requests over 3727ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 269 ms LCP 824 mshttps://ahajournals.org// https://ahajournals.org/ — 307 — 65 B — 149 ms — http/1.1https://ahajournals.org// https://ahajournals.org/ — 403 — 5.6 KiB — 13 ms — h2https://ahajournals.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff0ae56bacd283/cdn-cgi/challenge-platform/h/b/orc... https://ahajournals.org/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff0ae56bacd283 — 200 — 71.0 KiB — 31 ms — h3https://static.cloudflareinsights.com/beacon.min.js/vcd15cbe7772f49c399c6a5babf22c1241717689176015static.cloudflareinsights.com/beaco... https://static.cloudflareinsights.com/beacon.min.js/vcd15cbe7772f49c399c6a5babf22c1241717689176015 — 200 — 6.9 KiB — 53 ms — h2blob:https://ahajournals.org/f49ea1f3-104d-4d86-9d07-1b4fcff3cabcahajournals.org/f49ea1f3-104d-4d86-... blob:https://ahajournals.org/f49ea1f3-104d-4d86-9d07-1b4fcff3cabc — -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 — 31 ms — h3https://ahajournals.org/favicon.ico/favicon.ico https://ahajournals.org/favicon.ico — 403 — 7.6 KiB — 15 ms — h3https://ahajournals.org/cdn-cgi/rum?/cdn-cgi/rum? https://ahajournals.org/cdn-cgi/rum? — 204 — 141 B — 10 ms — h3https://ahajournals.org/favicon.ico/favicon.ico https://ahajournals.org/favicon.ico — 403 — 6.1 KiB — 18 ms — h3https://ahajournals.org/cdn-cgi/challenge-platform/h/b/flow/ov1/2861708471:1776798608:ErqmkTBsxeuPEUEQ-nj3Qg5gifcpzcridMS7hc7f-HQ/9eff0ae56bacd283/Gqm1XRt2jogQSC1oAxCtbmHbyRTbF8nuZ619har18Aw-1776802335-1.2.1.1-GYgFZATTbxsaVXMozep83qiId9ql1FEJqzf0w1PtsLN3yZDaniEmNhRmr1cJXovh/cdn-cgi/challenge-platform/h/b/flo... https://ahajournals.org/cdn-cgi/challenge-platform/h/b/flow/ov1/2861708471:1776798608:ErqmkTBsxeuPEUEQ-nj3Qg5gifcpzcridMS7hc7f-HQ/9eff0ae56bacd283/Gqm1XRt2jogQSC1oAxCtbmHbyRTbF8nuZ619har18Aw-1776802335-1.2.1.1-GYgFZATTbxsaVXMozep83qiId9ql1FEJqzf0w1PtsLN3yZDaniEmNhRmr1cJXovh — 200 — 13.5 KiB — 24 ms — h3blob:https://ahajournals.org/7605feb1-4f10-4d36-852d-82bee8515bc2ahajournals.org/7605feb1-4f10-4d36-... blob:https://ahajournals.org/7605feb1-4f10-4d36-852d-82bee8515bc2 — 200 — -1 B — 45 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/turnstile/f/ov2/av0/rch/co9ln/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/co9ln/0x4AAAAAAAAjq6WYeRDKmebM/light/fbE/new/normal?lang=auto — 200 — 90.0 KiB — 35 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 — 7 ms — h3blob:https://challenges.cloudflare.com/9395040f-e14d-4f07-8fb0-ef595752b0dcchallenges.cloudflare.com/9395040f-... blob:https://challenges.cloudflare.com/9395040f-e14d-4f07-8fb0-ef595752b0dc — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff0ae7ce58577d/AZ164KNNbff.shUSSMM0V4UURP8qRsN8jjdxdbuDQUI-1776802335-1.2.1.1-.uLZ7Iv1yicAsS8PmPwmVHGsQfxTjbSL1X2b0483SFicibsmunJppFtDc2rCLnfNchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff0ae7ce58577d/AZ164KNNbff.shUSSMM0V4UURP8qRsN8jjdxdbuDQUI-1776802335-1.2.1.1-.uLZ7Iv1yicAsS8PmPwmVHGsQfxTjbSL1X2b0483SFicibsmunJppFtDc2rCLnfN — 200 — 257.4 KiB — 129 ms — h3blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670cchallenges.cloudflare.com/9423ba5f-... blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c — 200 — -1 B — 108 ms — blobblob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670cchallenges.cloudflare.com/9423ba5f-... blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c — 200 — -1 B — 16 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/d/9eff0ae7ce58577d/1776802336317/Z2pxjPSLD1rnUq2challenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/d/9eff0ae7ce58577d/1776802336317/Z2pxjPSLD1rnUq2 — 200 — 2.2 KiB — 9 ms — h3blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670cchallenges.cloudflare.com/9423ba5f-... blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c — 200 — -1 B — 34 ms — blobblob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670cchallenges.cloudflare.com/9423ba5f-... blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c — 200 — -1 B — 0 ms — blobblob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670cchallenges.cloudflare.com/9423ba5f-... blob:https://challenges.cloudflare.com/9423ba5f-02d9-432d-8fb1-ba77eb8c670c — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/pat/9eff0ae7ce58577d/1776802336317/f116f674cdc30d6067b1f0a773c8f1cd5b3bb022450cdb67a4867f9ac66d0875/Lv98hHOY_QK0-xYchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/pat/9eff0ae7ce58577d/1776802336317/f116f674cdc30d6067b1f0a773c8f1cd5b3bb022450cdb67a4867f9ac66d0875/Lv98hHOY_QK0-xY — 401 — 1.7 KiB — 8 ms — h3https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff0ae7ce58577d/AZ164KNNbff.shUSSMM0V4UURP8qRsN8jjdxdbuDQUI-1776802335-1.2.1.1-.uLZ7Iv1yicAsS8PmPwmVHGsQfxTjbSL1X2b0483SFicibsmunJppFtDc2rCLnfNchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff0ae7ce58577d/AZ164KNNbff.shUSSMM0V4UURP8qRsN8jjdxdbuDQUI-1776802335-1.2.1.1-.uLZ7Iv1yicAsS8PmPwmVHGsQfxTjbSL1X2b0483SFicibsmunJppFtDc2rCLnfN — 200 — 22.8 KiB — 36 ms — h3blob:https://challenges.cloudflare.com/2ed6d0b7-e707-4829-b71b-43f4ebd6e363challenges.cloudflare.com/2ed6d0b7-... blob:https://challenges.cloudflare.com/2ed6d0b7-e707-4829-b71b-43f4ebd6e363 — 200 — -1 B — 22 ms — blob
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
10% of JavaScript execution is third-party
First-party Third-party 53ms · 0KB · $1/mo
Unattributable
Other
Optional
Execution 53ms
Transfer 0 KB
Monthly Cost $1/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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