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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
76
GRADE
C
FIX
4
REVIEW
4
PASS
7
INFO
2

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

Mobile Desktop
61
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
76
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.
92
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.

3.94 s

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

15.28 s

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

141 ms

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

0.004

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

5.66 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.

15.28 s

Page Load Progression

598 ms
1.2 s
1.8 s
2.4 s
3.0 s
3.6 s
4.2 s
4.8 s
Checks
17
7 PASS 4 REVIEW 4 FIX
F
Page Weight Budget
Action
7.9 MB transferred, 68 requests
FIX
7.9 MB transferred, 68 requests
Critical::
Page weighs 9.3 MB (7.9 MB transferred)
Warning::
Images are 7.3 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 7.3 MB
Info::
68 HTTP requests
Info::
Estimated 1.7 g CO2 per page load
7.9 MB / 2.4 MB budget
7.9 MB transferred
68 requests
1.7 g CO2 per page load
Images 7.3 MiB 92%
JavaScript 416.1 KiB 5%
Fonts 141.5 KiB 2%
CSS 68.9 KiB 1%
Other 26.9 KiB 0%
HTML 13.8 KiB 0%
Other 5.7 KiB 0%
Other 142 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

D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (7.9 MiB of 7.9 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
Page Weight Inventory
Action
68 resources · 7.9 MB · 120 KB savings available
FIX
68 resources · 7.9 MB · 120 KB savings available
Warning::
Page weight 6.9 MB over 1MB target
Got: 7.9 MB Expected: ≤ 1 MB
Info::
~120 KB of savings available
Warning::
64 third-party resources (100% of weight)
Info::
2 resources over 200KB
68 resources · 7.9 MiB · 64 third-party 6.9 MiB over 1MB target
Image 92% · 7.3 MiB
JavaScript 5% · 440.9 KiB
Font 2% · 141.5 KiB
CSS 1% · 68.9 KiB
Document 0% · 13.8 KiB
Other 0% · 142 B

~119.8 KiB of savings available

Remove unused JavaScript: 119.8 KiB
D
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.
Info::
ETag present — enables conditional (304) responses
Info::
Last-Modified header present

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

C
Image Optimization
Action
17 images, 0 KB saveable
REVIEW
17 images, 0 KB saveable
Warning::
https://www.crossref.org//img/crossref-logo-revers... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://assets.crossref.org/logo/crossref-logo-200... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
17 images 7.3 MB
0 oversized -0 KB
17 legacy format
2 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

C
JS Execution Cost
Action
1462ms total JS execution
REVIEW
1462ms total JS execution
Warning::
Unattributable: 424ms CPU time
Warning::
https://crossref.org/: 315ms CPU time
Info::
https://www.crossref.org//js/jquery.min.js: 205ms CPU time
Info::
https://resources.usersnap.com/widget-assets/js/en...: 160ms CPU time
Info::
https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7...: 136ms CPU time
Warning::
Third-party scripts: 1148ms (78% of total)

Main Thread Breakdown

Script Evaluation 41% Other 29% Style & Layout 14% Script Parsing & Compilation 9% Parse HTML & CSS 4%
ScriptTotalScriptingParse/CompileParty
Unattributable424ms28ms0ms3rd
https://crossref.org/315ms17ms3ms1st
https://www.crossref.org//js/jquery.min.js205ms151ms8ms3rd
https://resources.usersnap.com/widget-assets/js/entries/globalSetup/16705ad555292eaf.js160ms133ms24ms3rd
https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/config/TeX-AMS-MML_HTMLorMML.js?V=2.7.1136ms91ms20ms3rd
https://kit.fontawesome.com/7e709bc1c7.js107ms48ms19ms3rd
https://cdn.matomo.cloud/crossref.matomo.cloud/piwik.js63ms46ms16ms3rd
https://widget.usersnap.com/global/load/9d0a56e3-e101-4cf1-be76-fe738d9d5a8f?onload=onUsersnapLoad53ms50ms1ms3rd
B
JS Bundles
30 scripts, 120 KB unused
REVIEW
30 scripts, 120 KB unused
Warning::
https://cdn.matomo.cloud/crossref.matomo.cloud/piw...: 37 KB unused (66%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7...: 32 KB unused (55%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://resources.usersnap.com/widget-assets/js/en...: 29 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.datatables.net/1.10.16/js/jquery.dataT...: 22 KB unused (83%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 120 KB
120 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://cdn.matomo.cloud/crossref.matomo.cloud/piwik.js57 KB37 KB (66%)✓3rd
https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/config/TeX-AMS-MML_HTMLorMML.js?V=2.7.159 KB32 KB (55%)✓3rd
https://resources.usersnap.com/widget-assets/js/entries/globalSetup/16705ad555292eaf.js72 KB29 KB (40%)✓3rd
https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.js26 KB22 KB (83%)✓3rd
https://www.crossref.org//js/bootstrap.min.js10 KB—✓3rd
https://cdnjs.cloudflare.com/ajax/libs/masonry/4.1.0/masonry.pkgd.js14 KB—✗3rd
https://www.crossref.org//js/jquery.ui-min.js8 KB—✓3rd
https://www.crossref.org//js/js.cookie.js2 KB—✓3rd
https://www.crossref.org//js/jquery.cookiebar.js3 KB—✓3rd
https://www.crossref.org//js/jquery.fancybox.js14 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

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

C
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
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
4 fonts (142 KB)
PASS
4 fonts (142 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

142 KB total

Render-blocking

0

of 4

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s 16.0 s FCP 3.9 s LCP 15.3 shttps://use.fontawesome.com/releases/v4.6.3/fonts/fontawesome-webfont.woff2fontawesome-webfont.woff2 https://use.fontawesome.com/releases/v4.6.3/fonts/fontawesome-webfont.woff2 — 70.8 KiB — 76 ms — font-display: swaphttps://www.crossref.org/css/fonts/Inter-Web/Inter-Bold.woff2Inter-Bold.woff2 https://www.crossref.org/css/fonts/Inter-Web/Inter-Bold.woff2 — 0 B — 343 ms — font-display: swaphttps://www.crossref.org/css/fonts/Inter-Web/Inter-Regular.woff2Inter-Regular.woff2 https://www.crossref.org/css/fonts/Inter-Web/Inter-Regular.woff2 — 0 B — 559 ms — font-display: swaphttps://pro.fontawesome.com/releases/v5.7.2/webfonts/fa-brands-400.woff2fa-brands-400.woff2 https://pro.fontawesome.com/releases/v5.7.2/webfonts/fa-brands-400.woff2 — 70.7 KiB — 35 ms — font-display: swap
fontawesome-webfont.woff2 woff2 swap
Size 71 KB
Load time 76 ms
Start 881 ms
Risk FOUT — text flashes from fallback to web font
Inter-Bold.woff2 woff2 swap
Size 0 KB
Load time 343 ms
Start 968 ms
Risk FOUT — text flashes from fallback to web font
Inter-Regular.woff2 woff2 swap
Size 0 KB
Load time 559 ms
Start 968 ms
Risk FOUT — text flashes from fallback to web font
fa-brands-400.woff2 woff2 swap
Size 71 KB
Load time 35 ms
Start 992 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)
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+
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
Network Waterfall
68 requests over 2126ms
INFO
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s 16.0 s FCP 3.9 s LCP 15.3 shttps://crossref.org// https://crossref.org/ — 200 — 8.7 KiB — 301 ms — h2https://pro.fontawesome.com/releases/v5.7.2/css/all.csspro.fontawesome.com/releases/v5.7.2... https://pro.fontawesome.com/releases/v5.7.2/css/all.css — 200 — 16.0 KiB — 116 ms — h2https://www.crossref.org//css/bootstrap.min.csswww.crossref.org//css/bootstrap.min... https://www.crossref.org//css/bootstrap.min.css — 200 — 18.3 KiB — 405 ms — h2https://use.fontawesome.com/1873acdb2d.jsuse.fontawesome.com/1873acdb2d.js https://use.fontawesome.com/1873acdb2d.js — 200 — 4.2 KiB — 242 ms — h2https://cdn.datatables.net/1.10.16/css/jquery.dataTables.min.csscdn.datatables.net/1.10.16/css/jque... https://cdn.datatables.net/1.10.16/css/jquery.dataTables.min.css — 200 — 2.4 KiB — 103 ms — h2https://cdn.datatables.net/buttons/1.5.1/css/buttons.dataTables.min.csscdn.datatables.net/buttons/1.5.1/cs... https://cdn.datatables.net/buttons/1.5.1/css/buttons.dataTables.min.css — 200 — 1.8 KiB — 109 ms — h2https://www.crossref.org//css/syntax.csswww.crossref.org//css/syntax.css https://www.crossref.org//css/syntax.css — 200 — 1.4 KiB — 495 ms — h2https://www.crossref.org/css/crossref.min.05ecfb7355911548d11343a672a95ea3d1320edf72da2de9b776f402bb6bedd3.csswww.crossref.org/css/crossref.min.0... https://www.crossref.org/css/crossref.min.05ecfb7355911548d11343a672a95ea3d1320edf72da2de9b776f402bb6bedd3.css — 200 — 20.7 KiB — 491 ms — h2https://www.crossref.org/css/print.min.5b37715a8e5bdae856e4d3b1fd9d7c8dad0c1d2cee2ed79d6397d375334339ce.csswww.crossref.org/css/print.min.5b37... https://www.crossref.org/css/print.min.5b37715a8e5bdae856e4d3b1fd9d7c8dad0c1d2cee2ed79d6397d375334339ce.css — 200 — 779 B — 492 ms — h2https://cdn.jsdelivr.net/algoliasearch/3/algoliasearch.min.jscdn.jsdelivr.net/algoliasearch/3/al... https://cdn.jsdelivr.net/algoliasearch/3/algoliasearch.min.js — 200 — 19.3 KiB — 50 ms — h2https://cdn.jsdelivr.net/autocomplete.js/0/autocomplete.min.jscdn.jsdelivr.net/autocomplete.js/0/... https://cdn.jsdelivr.net/autocomplete.js/0/autocomplete.min.js — 200 — 18.5 KiB — 49 ms — h2https://www.crossref.org//img/crossref-logo-reverse.svgwww.crossref.org//img/crossref-logo... https://www.crossref.org//img/crossref-logo-reverse.svg — 200 — 1.4 KiB — 490 ms — h2https://assets.crossref.org/logo/crossref-logo-200.svgassets.crossref.org/logo/crossref-l... https://assets.crossref.org/logo/crossref-logo-200.svg — 200 — 3.4 KiB — 304 ms — http/1.1https://crossref.org/images/footer/cc.svg/images/footer/cc.svg https://crossref.org/images/footer/cc.svg — 200 — 1.6 KiB — 102 ms — h2https://use.fontawesome.com/1873acdb2d.cssuse.fontawesome.com/1873acdb2d.css https://use.fontawesome.com/1873acdb2d.css — 200 — 685 B — 120 ms — h2https://crossref.org/images/footer/by.svg/images/footer/by.svg https://crossref.org/images/footer/by.svg — 200 — 1.2 KiB — 102 ms — h2https://status.crossref.org/embed/script.jsstatus.crossref.org/embed/script.js https://status.crossref.org/embed/script.js — 200 — 1.5 KiB — 339 ms — h2https://kit.fontawesome.com/7e709bc1c7.jskit.fontawesome.com/7e709bc1c7.js https://kit.fontawesome.com/7e709bc1c7.js — 200 — 5.6 KiB — 213 ms — h2https://www.crossref.org//js/jquery.min.jswww.crossref.org//js/jquery.min.js https://www.crossref.org//js/jquery.min.js — 200 — 28.9 KiB — 115 ms — h2https://www.crossref.org//js/jquery.ui-min.jswww.crossref.org//js/jquery.ui-min.... https://www.crossref.org//js/jquery.ui-min.js — 200 — 8.3 KiB — 108 ms — h2https://www.crossref.org//js/js.cookie.jswww.crossref.org//js/js.cookie.js https://www.crossref.org//js/js.cookie.js — 200 — 1.6 KiB — 111 ms — h2https://www.crossref.org//js/jquery.cookiebar.jswww.crossref.org//js/jquery.cookieb... https://www.crossref.org//js/jquery.cookiebar.js — 200 — 2.7 KiB — 302 ms — h2https://www.crossref.org//js/jquery.fancybox.jswww.crossref.org//js/jquery.fancybo... https://www.crossref.org//js/jquery.fancybox.js — 200 — 13.6 KiB — 204 ms — h2https://www.crossref.org//js/jquery.validate.jswww.crossref.org//js/jquery.validat... https://www.crossref.org//js/jquery.validate.js — 200 — 12.2 KiB — 112 ms — h2https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.jscdn.datatables.net/1.10.16/js/jquer... https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.js — 200 — 26.4 KiB — 33 ms — h2https://cdn.datatables.net/buttons/1.5.1/js/dataTables.buttons.min.jscdn.datatables.net/buttons/1.5.1/js... https://cdn.datatables.net/buttons/1.5.1/js/dataTables.buttons.min.js — 200 — 5.8 KiB — 31 ms — h2https://cdn.datatables.net/buttons/1.5.1/js/buttons.html5.min.jscdn.datatables.net/buttons/1.5.1/js... https://cdn.datatables.net/buttons/1.5.1/js/buttons.html5.min.js — 200 — 6.1 KiB — 33 ms — h2https://www.crossref.org//js/bootstrap.min.jswww.crossref.org//js/bootstrap.min.... https://www.crossref.org//js/bootstrap.min.js — 200 — 9.7 KiB — 300 ms — h2https://www.crossref.org//js/jquery.sticky-kit.min.jswww.crossref.org//js/jquery.sticky-... https://www.crossref.org//js/jquery.sticky-kit.min.js — 200 — 1.5 KiB — 301 ms — h2https://www.crossref.org//js/crossref.js?v=1www.crossref.org//js/crossref.js?v=... https://www.crossref.org//js/crossref.js?v=1 — 200 — 9.0 KiB — 301 ms — h2
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s 16.0 s FCP 3.9 s LCP 15.3 shttps://crossref.org// https://crossref.org/ — 200 — 8.7 KiB — 301 ms — h2https://pro.fontawesome.com/releases/v5.7.2/css/all.csspro.fontawesome.com/releases/v5.7.2... https://pro.fontawesome.com/releases/v5.7.2/css/all.css — 200 — 16.0 KiB — 116 ms — h2https://www.crossref.org//css/bootstrap.min.csswww.crossref.org//css/bootstrap.min... https://www.crossref.org//css/bootstrap.min.css — 200 — 18.3 KiB — 405 ms — h2https://use.fontawesome.com/1873acdb2d.jsuse.fontawesome.com/1873acdb2d.js https://use.fontawesome.com/1873acdb2d.js — 200 — 4.2 KiB — 242 ms — h2https://cdn.datatables.net/1.10.16/css/jquery.dataTables.min.csscdn.datatables.net/1.10.16/css/jque... https://cdn.datatables.net/1.10.16/css/jquery.dataTables.min.css — 200 — 2.4 KiB — 103 ms — h2https://cdn.datatables.net/buttons/1.5.1/css/buttons.dataTables.min.csscdn.datatables.net/buttons/1.5.1/cs... https://cdn.datatables.net/buttons/1.5.1/css/buttons.dataTables.min.css — 200 — 1.8 KiB — 109 ms — h2https://www.crossref.org//css/syntax.csswww.crossref.org//css/syntax.css https://www.crossref.org//css/syntax.css — 200 — 1.4 KiB — 495 ms — h2https://www.crossref.org/css/crossref.min.05ecfb7355911548d11343a672a95ea3d1320edf72da2de9b776f402bb6bedd3.csswww.crossref.org/css/crossref.min.0... https://www.crossref.org/css/crossref.min.05ecfb7355911548d11343a672a95ea3d1320edf72da2de9b776f402bb6bedd3.css — 200 — 20.7 KiB — 491 ms — h2https://www.crossref.org/css/print.min.5b37715a8e5bdae856e4d3b1fd9d7c8dad0c1d2cee2ed79d6397d375334339ce.csswww.crossref.org/css/print.min.5b37... https://www.crossref.org/css/print.min.5b37715a8e5bdae856e4d3b1fd9d7c8dad0c1d2cee2ed79d6397d375334339ce.css — 200 — 779 B — 492 ms — h2https://cdn.jsdelivr.net/algoliasearch/3/algoliasearch.min.jscdn.jsdelivr.net/algoliasearch/3/al... https://cdn.jsdelivr.net/algoliasearch/3/algoliasearch.min.js — 200 — 19.3 KiB — 50 ms — h2https://cdn.jsdelivr.net/autocomplete.js/0/autocomplete.min.jscdn.jsdelivr.net/autocomplete.js/0/... https://cdn.jsdelivr.net/autocomplete.js/0/autocomplete.min.js — 200 — 18.5 KiB — 49 ms — h2https://www.crossref.org//img/crossref-logo-reverse.svgwww.crossref.org//img/crossref-logo... https://www.crossref.org//img/crossref-logo-reverse.svg — 200 — 1.4 KiB — 490 ms — h2https://assets.crossref.org/logo/crossref-logo-200.svgassets.crossref.org/logo/crossref-l... https://assets.crossref.org/logo/crossref-logo-200.svg — 200 — 3.4 KiB — 304 ms — http/1.1https://crossref.org/images/footer/cc.svg/images/footer/cc.svg https://crossref.org/images/footer/cc.svg — 200 — 1.6 KiB — 102 ms — h2https://use.fontawesome.com/1873acdb2d.cssuse.fontawesome.com/1873acdb2d.css https://use.fontawesome.com/1873acdb2d.css — 200 — 685 B — 120 ms — h2https://crossref.org/images/footer/by.svg/images/footer/by.svg https://crossref.org/images/footer/by.svg — 200 — 1.2 KiB — 102 ms — h2https://status.crossref.org/embed/script.jsstatus.crossref.org/embed/script.js https://status.crossref.org/embed/script.js — 200 — 1.5 KiB — 339 ms — h2https://kit.fontawesome.com/7e709bc1c7.jskit.fontawesome.com/7e709bc1c7.js https://kit.fontawesome.com/7e709bc1c7.js — 200 — 5.6 KiB — 213 ms — h2https://www.crossref.org//js/jquery.min.jswww.crossref.org//js/jquery.min.js https://www.crossref.org//js/jquery.min.js — 200 — 28.9 KiB — 115 ms — h2https://www.crossref.org//js/jquery.ui-min.jswww.crossref.org//js/jquery.ui-min.... https://www.crossref.org//js/jquery.ui-min.js — 200 — 8.3 KiB — 108 ms — h2https://www.crossref.org//js/js.cookie.jswww.crossref.org//js/js.cookie.js https://www.crossref.org//js/js.cookie.js — 200 — 1.6 KiB — 111 ms — h2https://www.crossref.org//js/jquery.cookiebar.jswww.crossref.org//js/jquery.cookieb... https://www.crossref.org//js/jquery.cookiebar.js — 200 — 2.7 KiB — 302 ms — h2https://www.crossref.org//js/jquery.fancybox.jswww.crossref.org//js/jquery.fancybo... https://www.crossref.org//js/jquery.fancybox.js — 200 — 13.6 KiB — 204 ms — h2https://www.crossref.org//js/jquery.validate.jswww.crossref.org//js/jquery.validat... https://www.crossref.org//js/jquery.validate.js — 200 — 12.2 KiB — 112 ms — h2https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.jscdn.datatables.net/1.10.16/js/jquer... https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.js — 200 — 26.4 KiB — 33 ms — h2https://cdn.datatables.net/buttons/1.5.1/js/dataTables.buttons.min.jscdn.datatables.net/buttons/1.5.1/js... https://cdn.datatables.net/buttons/1.5.1/js/dataTables.buttons.min.js — 200 — 5.8 KiB — 31 ms — h2https://cdn.datatables.net/buttons/1.5.1/js/buttons.html5.min.jscdn.datatables.net/buttons/1.5.1/js... https://cdn.datatables.net/buttons/1.5.1/js/buttons.html5.min.js — 200 — 6.1 KiB — 33 ms — h2https://www.crossref.org//js/bootstrap.min.jswww.crossref.org//js/bootstrap.min.... https://www.crossref.org//js/bootstrap.min.js — 200 — 9.7 KiB — 300 ms — h2https://www.crossref.org//js/jquery.sticky-kit.min.jswww.crossref.org//js/jquery.sticky-... https://www.crossref.org//js/jquery.sticky-kit.min.js — 200 — 1.5 KiB — 301 ms — h2https://www.crossref.org//js/crossref.js?v=1www.crossref.org//js/crossref.js?v=... https://www.crossref.org//js/crossref.js?v=1 — 200 — 9.0 KiB — 301 ms — h2https://cdnjs.cloudflare.com/ajax/libs/masonry/4.1.0/masonry.pkgd.jscdnjs.cloudflare.com/ajax/libs/maso... https://cdnjs.cloudflare.com/ajax/libs/masonry/4.1.0/masonry.pkgd.js — 200 — 13.7 KiB — 101 ms — h2https://www.crossref.org//images/staff/susan17-thumbnail.pngwww.crossref.org//images/staff/susa... https://www.crossref.org//images/staff/susan17-thumbnail.png — 200 — 15.5 KiB — 301 ms — h2https://www.crossref.org//images/staff/amanda2.jpgwww.crossref.org//images/staff/aman... https://www.crossref.org//images/staff/amanda2.jpg — 200 — 100.8 KiB — 301 ms — h2https://www.crossref.org//images/staff/luis-thumbnail.pngwww.crossref.org//images/staff/luis... https://www.crossref.org//images/staff/luis-thumbnail.png — 200 — 19.3 KiB — 300 ms — h2https://www.crossref.org//images/staff/dominika-thumbnail.jpgwww.crossref.org//images/staff/domi... https://www.crossref.org//images/staff/dominika-thumbnail.jpg — 200 — 10.0 KiB — 204 ms — h2https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMMLcdnjs.cloudflare.com/ajax/libs/math... https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML — 200 — 16.8 KiB — 111 ms — h2https://use.fontawesome.com/releases/v4.6.3/css/font-awesome-css.min.cssuse.fontawesome.com/releases/v4.6.3... https://use.fontawesome.com/releases/v4.6.3/css/font-awesome-css.min.css — 200 — 6.9 KiB — 28 ms — h2https://use.fontawesome.com/releases/v4.6.3/fonts/fontawesome-webfont.woff2use.fontawesome.com/releases/v4.6.3... https://use.fontawesome.com/releases/v4.6.3/fonts/fontawesome-webfont.woff2 — 200 — 70.8 KiB — 76 ms — h2https://www.crossref.org/img/nav-footer.svgwww.crossref.org/img/nav-footer.svg https://www.crossref.org/img/nav-footer.svg — 200 — 1.2 KiB — 166 ms — h2https://www.crossref.org/img/magnifying-glass.svgwww.crossref.org/img/magnifying-gla... https://www.crossref.org/img/magnifying-glass.svg — 200 — 1.9 KiB — 167 ms — h2https://www.crossref.org//images/homepage-images/bogota-city-mountain-view.jpgwww.crossref.org//images/homepage-i... https://www.crossref.org//images/homepage-images/bogota-city-mountain-view.jpg — 200 — 1.4 MiB — 663 ms — h2https://www.crossref.org//images/homepage-images/featured/feature-metadata-enrichment1.pngwww.crossref.org//images/homepage-i... https://www.crossref.org//images/homepage-images/featured/feature-metadata-enrichment1.png — 200 — 148.4 KiB — 458 ms — h2https://www.crossref.org//images/homepage-images/featured/community-update-2026.pngwww.crossref.org//images/homepage-i... https://www.crossref.org//images/homepage-images/featured/community-update-2026.png — 200 — 65.3 KiB — 260 ms — h2https://www.crossref.org//images/homepage-images/featured/feature-data-citation.pngwww.crossref.org//images/homepage-i... https://www.crossref.org//images/homepage-images/featured/feature-data-citation.png — 200 — 47.6 KiB — 268 ms — h2https://www.crossref.org//images/homepage-images/featured/sao-paulo-countryside.jpgwww.crossref.org//images/homepage-i... https://www.crossref.org//images/homepage-images/featured/sao-paulo-countryside.jpg — 200 — 5.3 MiB — 616 ms — h2https://www.crossref.org//images/homepage-images/featured/feature-healthcheck-tan.pngwww.crossref.org//images/homepage-i... https://www.crossref.org//images/homepage-images/featured/feature-healthcheck-tan.png — 200 — 188.7 KiB — 354 ms — h2https://www.crossref.org//images/homepage-images/featured/gem-trees.jpgwww.crossref.org//images/homepage-i... https://www.crossref.org//images/homepage-images/featured/gem-trees.jpg — 200 — 56.2 KiB — 354 ms — h2https://www.crossref.org/css/fonts/Inter-Web/Inter-Bold.woff2www.crossref.org/css/fonts/Inter-We... https://www.crossref.org/css/fonts/Inter-Web/Inter-Bold.woff2 — -1 — 0 B — 343 ms — https://www.crossref.org/css/fonts/Inter-Web/Inter-Regular.woff2www.crossref.org/css/fonts/Inter-We... https://www.crossref.org/css/fonts/Inter-Web/Inter-Regular.woff2 — -1 — 0 B — 559 ms — https://pro.fontawesome.com/releases/v5.7.2/webfonts/fa-brands-400.woff2pro.fontawesome.com/releases/v5.7.2... https://pro.fontawesome.com/releases/v5.7.2/webfonts/fa-brands-400.woff2 — 200 — 70.7 KiB — 35 ms — h2https://ka-p.fontawesome.com/releases/v6.7.2/js/pro-v4-shims.min.js?token=7e709bc1c7ka-p.fontawesome.com/releases/v6.7.... https://ka-p.fontawesome.com/releases/v6.7.2/js/pro-v4-shims.min.js?token=7e709bc1c7 — 200 — 7.4 KiB — 92 ms — h2https://ka-p.fontawesome.com/releases/v6.7.2/js/pro.min.js?token=7e709bc1c7ka-p.fontawesome.com/releases/v6.7.... https://ka-p.fontawesome.com/releases/v6.7.2/js/pro.min.js?token=7e709bc1c7 — 200 — 17.4 KiB — 83 ms — h2https://cpl595mrvlzp.statuspage.io/embed/frame?mobile=truecpl595mrvlzp.statuspage.io/embed/fr... https://cpl595mrvlzp.statuspage.io/embed/frame?mobile=true — 200 — 5.1 KiB — 458 ms — h2https://outreach.crossref.org/cdnr/93/acton/bn/tracker/16781outreach.crossref.org/cdnr/93/acton... https://outreach.crossref.org/cdnr/93/acton/bn/tracker/16781 — 200 — 491 B — 825 ms — http/1.1https://cdn.matomo.cloud/crossref.matomo.cloud/piwik.jscdn.matomo.cloud/crossref.matomo.cl... https://cdn.matomo.cloud/crossref.matomo.cloud/piwik.js — 200 — 56.8 KiB — 65 ms — h2https://widget.usersnap.com/global/load/9d0a56e3-e101-4cf1-be76-fe738d9d5a8f?onload=onUsersnapLoadwidget.usersnap.com/global/load/9d0... https://widget.usersnap.com/global/load/9d0a56e3-e101-4cf1-be76-fe738d9d5a8f?onload=onUsersnapLoad — 200 — 4.0 KiB — 204 ms — h2https://player.vimeo.com/api/player.jsplayer.vimeo.com/api/player.js https://player.vimeo.com/api/player.js — 200 — 9.0 KiB — 113 ms — http/1.1https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/config/TeX-AMS-MML_HTMLorMML.js?V=2.7.1cdnjs.cloudflare.com/ajax/libs/math... https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/config/TeX-AMS-MML_HTMLorMML.js?V=2.7.1 — 200 — 59.0 KiB — 30 ms — h2https://ka-p.fontawesome.com/releases/v6.7.2/svgs/brands/bluesky.svg?token=7e709bc1c7ka-p.fontawesome.com/releases/v6.7.... https://ka-p.fontawesome.com/releases/v6.7.2/svgs/brands/bluesky.svg?token=7e709bc1c7 — 200 — 565 B — 31 ms — h2https://ka-p.fontawesome.com/releases/v6.7.2/svgs/brands/mastodon.svg?token=7e709bc1c7ka-p.fontawesome.com/releases/v6.7.... https://ka-p.fontawesome.com/releases/v6.7.2/svgs/brands/mastodon.svg?token=7e709bc1c7 — 200 — 597 B — 32 ms — h2https://ka-p.fontawesome.com/releases/v6.7.2/svgs/brands/linkedin.svg?token=7e709bc1c7ka-p.fontawesome.com/releases/v6.7.... https://ka-p.fontawesome.com/releases/v6.7.2/svgs/brands/linkedin.svg?token=7e709bc1c7 — 200 — 531 B — 31 ms — h2https://ka-p.fontawesome.com/releases/v6.7.2/svgs/brands/youtube.svg?token=7e709bc1c7ka-p.fontawesome.com/releases/v6.7.... https://ka-p.fontawesome.com/releases/v6.7.2/svgs/brands/youtube.svg?token=7e709bc1c7 — 200 — 531 B — 33 ms — h2https://crossref.matomo.cloud/piwik.php?action_name=You%20are%20Crossref%20-%20Crossref&idsite=1&rec=1&r=483843&h=21&m=7&s=13&url=https%3A%2F%2Fcrossref.org%2F&_id=ca983c9fd6ee98b4&_idn=1&send_image=0&_refts=0&pv_id=vgcoHr&fa_pv=1&fa_fp[0][fa_vid]=OEAwaz&fa_fp[0][fa_id]=search-form&fa_fp[0][fa_fv]=1&pf_net=199&pf_srv=101&pf_tfr=1&pf_dm1=891&uadata=%7B%22formFactors%22%3A%5B%22Desktop%22%5D%2C%22fullVersionList%22%3A%5B%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22147.0.7727.101%22%7D%2C%7B%22brand%22%3A%22Not.A%2FBrand%22%2C%22version%22%3A%228.0.0.0%22%7D%5D%2C%22mobile%22%3Atrue%2C%22model%22%3A%22moto%20g%20power%20(2022)%22%2C%22platform%22%3A%22Android%22%2C%22platformVersion%22%3A%2211.0%22%7D&pdf=1&qt=0&realp=0&wma=0&fla=0&java=0&ag=0&cookie=1&res=412x823crossref.matomo.cloud/piwik.php?act... https://crossref.matomo.cloud/piwik.php?action_name=You%20are%20Crossref%20-%20Crossref&idsite=1&rec=1&r=483843&h=21&m=7&s=13&url=https%3A%2F%2Fcrossref.org%2F&_id=ca983c9fd6ee98b4&_idn=1&send_image=0&_refts=0&pv_id=vgcoHr&fa_pv=1&fa_fp[0][fa_vid]=OEAwaz&fa_fp[0][fa_id]=search-form&fa_fp[0][fa_fv]=1&pf_net=199&pf_srv=101&pf_tfr=1&pf_dm1=891&uadata=%7B%22formFactors%22%3A%5B%22Desktop%22%5D%2C%22fullVersionList%22%3A%5B%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22147.0.7727.101%22%7D%2C%7B%22brand%22%3A%22Not.A%2FBrand%22%2C%22version%22%3A%228.0.0.0%22%7D%5D%2C%22mobile%22%3Atrue%2C%22model%22%3A%22moto%20g%20power%20(2022)%22%2C%22platform%22%3A%22Android%22%2C%22platformVersion%22%3A%2211.0%22%7D&pdf=1&qt=0&realp=0&wma=0&fla=0&java=0&ag=0&cookie=1&res=412x823 — 204 — 142 B — 218 ms — h2https://crossref.matomo.cloud/plugins/HeatmapSessionRecording/configs.php?idsite=1&trackerid=IMGAnM&url=https%3A%2F%2Fcrossref.org%2Fcrossref.matomo.cloud/plugins/Heatm... https://crossref.matomo.cloud/plugins/HeatmapSessionRecording/configs.php?idsite=1&trackerid=IMGAnM&url=https%3A%2F%2Fcrossref.org%2F — 200 — 269 B — 140 ms — h2https://resources.usersnap.com/widget-assets/js/entries/globalSetup/16705ad555292eaf.jsresources.usersnap.com/widget-asset... https://resources.usersnap.com/widget-assets/js/entries/globalSetup/16705ad555292eaf.js — 200 — 72.2 KiB — 63 ms — h2https://resources.usersnap.com/widget-assets/js/chunks/6621/ee57248d5686d789.jsresources.usersnap.com/widget-asset... https://resources.usersnap.com/widget-assets/js/chunks/6621/ee57248d5686d789.js — 200 — 7.2 KiB — 5 ms — h2https://resources.usersnap.com/widget-assets/js/chunks/widgetApi/205c166efb631a52.jsresources.usersnap.com/widget-asset... https://resources.usersnap.com/widget-assets/js/chunks/widgetApi/205c166efb631a52.js — 200 — 1.8 KiB — 6 ms — h2https://crossref.org/favicon.ico/favicon.ico https://crossref.org/favicon.ico — 200 — 5.7 KiB — 101 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
78% of JavaScript execution is third-party
First-party Third-party 1148ms · 227KB · $4/mo
Unattributable
Other
Costly
Execution 424ms
Transfer 0 KB
Monthly Cost $1/mo
www.crossref.org
Other
Costly
Execution 205ms
Transfer 29 KB
Monthly Cost $1/mo
resources.usersnap.com
Other
Optional
Execution 160ms
Transfer 72 KB
Unused 40%
Monthly Cost $1/mo
cdnjs
CDN
Optional
Execution 136ms
Transfer 59 KB
Unused 55%
Monthly Cost $0/mo
kit.fontawesome.com
Other
Optional
Execution 107ms
Transfer 6 KB
Monthly Cost $0/mo
Matomo
Analytics
Optional
Execution 63ms
Transfer 57 KB
Unused 66%
Monthly Cost $0/mo
widget.usersnap.com
Other
Optional
Execution 53ms
Transfer 4 KB
Monthly Cost $0/mo

These scripts may cost more than they're worth

  • Unattributable adds 424ms and costs ~$1/month
  • www.crossref.org adds 205ms and costs ~$1/month

78% 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

Unattributable takes 424ms 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.crossref.org takes 205ms 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

55% of cdnjs's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

66% of Matomo's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

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.

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