Skip to content
https://aaas.org

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
86
GRADE
B
FIX
2
REVIEW
4
PASS
7
INFO
2

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

Mobile Desktop
93
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
79
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
85
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.

1.12 s

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

1.41 s

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

0 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.

1.12 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.

1.41 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
15
7 PASS 4 REVIEW 2 FIX
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 (1.1 MiB of 1.1 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
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.

No Cache-Control header

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

B
Page Weight Budget
1.1 MB transferred, 45 requests
REVIEW
1.1 MB transferred, 45 requests
Info::
Page weighs 2.6 MB (1.1 MB transferred)
Info::
45 HTTP requests
Info::
Estimated 0.23 g CO2 per page load
1.1 MB / 2.4 MB budget
1.1 MB transferred
45 requests
0.23 g CO2 per page load
Images 430.6 KiB 38%
JavaScript 402.7 KiB 36%
Fonts 190.2 KiB 17%
CSS 69.1 KiB 6%
HTML 27.2 KiB 2%
Other 3.5 KiB 0%
0 2.4 MB 4.9 MB
Under budget
C
Image Optimization
Action
23 images, 0 KB saveable
REVIEW
23 images, 0 KB saveable
Warning::
https://www.aaas.org/sites/default/files/styles/la... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.aaas.org/sites/default/files/styles/fr... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.aaas.org/sites/default/files/styles/la... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.aaas.org/sites/default/files/2026-04/R... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
23 images 431 KB
0 oversized -0 KB
4 legacy format
4 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

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

B
JS Bundles
12 scripts, 130 KB unused
REVIEW
12 scripts, 130 KB unused
Warning::
https://code.jquery.com/ui/1.13.0/jquery-ui.min.js: 59 KB unused (89%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.aaas.org/sites/default/files/js/js_Vap...: 24 KB unused (79%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.aaas.org/core/assets/vendor/jquery/jqu...: 24 KB unused (75%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cmp.osano.com/HuPXR0mFqn/65f07145-79fc-4c5...: 23 KB unused (33%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 130 KB
130 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://code.jquery.com/ui/1.13.0/jquery-ui.min.js67 KB59 KB (89%)✓3rd
https://www.aaas.org/sites/default/files/js/js_VapNRNoXd9QYusWCQLzrRkkd6SiZj36-H_4RU1rh5u4.js?scope=footer&delta=1&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo30 KB24 KB (79%)✓3rd
https://www.aaas.org/core/assets/vendor/jquery/jquery.min.js?v=4.0.0-rc.132 KB24 KB (75%)✓3rd
https://cmp.osano.com/HuPXR0mFqn/65f07145-79fc-4c5f-91b5-0fe679afddcc/osano.js72 KB23 KB (33%)✓3rd
https://www.aaas.org/sites/default/files/aaas/pre_osano_prod.js1 KB—✓3rd
https://assets.adobedtm.com/a48c09ba9d50/1e36ca10b673/launch-ea90f2ac46ad.min.js98 KB—✓3rd
https://code.jquery.com/jquery-3.6.4.min.js30 KB—✓3rd
https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.6/underscore-umd-min.js7 KB—✓3rd
https://www.aaas.org/sites/default/files/js/js_SytI1DevUZqbsifl6v4DWyz9fKcKO3zRuvs68WJj_j0.js?scope=footer&delta=3&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo39 KB—✓3rd
https://weby.aaas.org/weby_bundle_v2.js25 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+
JS Execution Cost
368ms total JS execution
PASS
368ms total JS execution
Info::
https://www.aaas.org/: 146ms CPU time
Info::
https://cmp.osano.com/HuPXR0mFqn/65f07145-79fc-4c5...: 106ms CPU time
Info::
https://www.aaas.org/sites/default/files/js/js_Syt...: 59ms CPU time
Info::
Unattributable: 57ms CPU time
Warning::
Third-party scripts: 368ms (100% of total)

Main Thread Breakdown

Script Evaluation 38% Other 24% Style & Layout 23% Rendering 6% Script Parsing & Compilation 5% Parse HTML & CSS 4%
ScriptTotalScriptingParse/CompileParty
https://www.aaas.org/146ms2ms0ms3rd
https://cmp.osano.com/HuPXR0mFqn/65f07145-79fc-4c5f-91b5-0fe679afddcc/osano.js106ms85ms5ms3rd
https://www.aaas.org/sites/default/files/js/js_SytI1DevUZqbsifl6v4DWyz9fKcKO3zRuvs68WJj_j0.js?scope=footer&delta=3&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo59ms43ms2ms3rd
Unattributable57ms1ms0ms3rd
A+
Font Loading
3 fonts (190 KB)
PASS
3 fonts (190 KB)
Info::
3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

3

190 KB total

Render-blocking

0

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 1.1 s LCP 1.4 shttps://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2memvYaGs126MiZpBA-UvWbX... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 42.0 KiB — 66 ms — font-display: swaphttps://fonts.gstatic.com/s/opensans/v44/memtYaGs126MiZpBA-UFUIcVXSCEkx2cmqvXlWqWuU6FxZCJgg.woff2memtYaGs126MiZpBA-UFUIc... https://fonts.gstatic.com/s/opensans/v44/memtYaGs126MiZpBA-UFUIcVXSCEkx2cmqvXlWqWuU6FxZCJgg.woff2 — 44.0 KiB — 70 ms — font-display: swaphttps://www.aaas.org/themes/custom/aaas_v2/assets/fonts/icomoon.ttf?2017_11_28_001=icomoon.ttf https://www.aaas.org/themes/custom/aaas_v2/assets/fonts/icomoon.ttf?2017_11_28_001= — 104.1 KiB — 9 ms — font-display: swap
memvYaGs126MiZpBA-UvWbX... woff2 swap
Size 42 KB
Load time 66 ms
Start 220 ms
Risk FOUT — text flashes from fallback to web font
memtYaGs126MiZpBA-UFUIc... woff2 swap
Size 44 KB
Load time 70 ms
Start 220 ms
Risk FOUT — text flashes from fallback to web font
icomoon.ttf ttf swap
Size 104 KB
Load time 9 ms
Start 222 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~83 KB and ~166 ms

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
45 resources · 1.1 MB · 130 KB savings available
PASS
45 resources · 1.1 MB · 130 KB savings available
Warning::
Page weight 99 KB over 1MB target
Got: 1.1 MB Expected: ≤ 1 MB
Info::
~130 KB of savings available
Warning::
44 third-party resources (100% of weight)
45 resources · 1.1 MiB · 44 third-party 99.2 KiB over 1MB target
Image 39% · 433.9 KiB
JavaScript 36% · 402.7 KiB
Font 17% · 190.2 KiB
CSS 6% · 69.1 KiB
Document 2% · 27.2 KiB
Other 0% · 207 B

~129.9 KiB of savings available

Remove unused JavaScript: 129.9 KiB
Network Waterfall
45 requests over 405ms
INFO
0 ms 500 ms 1.0 s FCP 1.1 s LCP 1.4 shttps://aaas.org// https://aaas.org/ — 301 — 207 B — 5 ms — h2https://www.aaas.org/www.aaas.org/ https://www.aaas.org/ — 200 — 26.1 KiB — 7 ms — h2https://www.aaas.org/sites/default/files/aaas/pre_osano_prod.jswww.aaas.org/sites/default/files/aa... https://www.aaas.org/sites/default/files/aaas/pre_osano_prod.js — 200 — 555 B — 9 ms — h2https://cmp.osano.com/HuPXR0mFqn/65f07145-79fc-4c5f-91b5-0fe679afddcc/osano.jscmp.osano.com/HuPXR0mFqn/65f07145-7... https://cmp.osano.com/HuPXR0mFqn/65f07145-79fc-4c5f-91b5-0fe679afddcc/osano.js — 200 — 71.9 KiB — 60 ms — h3https://www.aaas.org/sites/default/files/css/css_X44nJuq7WK8EaMaIccWsr-qJAZRK5CnZ4GGoAAjw8KE.css?delta=0&language=en&theme=aaas_v2&include=eJxLTEwsji8z0k_PyU9KzNEpriwuSc3VT0osTgUAg5EJ2Qwww.aaas.org/sites/default/files/cs... https://www.aaas.org/sites/default/files/css/css_X44nJuq7WK8EaMaIccWsr-qJAZRK5CnZ4GGoAAjw8KE.css?delta=0&language=en&theme=aaas_v2&include=eJxLTEwsji8z0k_PyU9KzNEpriwuSc3VT0osTgUAg5EJ2Q — 200 — 4.4 KiB — 11 ms — h2https://www.aaas.org/sites/default/files/css/css_x57-XDHutk6povG07wlJbji7BXEbrZEpRnJSmBgh3K0.css?delta=1&language=en&theme=aaas_v2&include=eJxLTEwsji8z0k_PyU9KzNEpriwuSc3VT0osTgUAg5EJ2Qwww.aaas.org/sites/default/files/cs... https://www.aaas.org/sites/default/files/css/css_x57-XDHutk6povG07wlJbji7BXEbrZEpRnJSmBgh3K0.css?delta=1&language=en&theme=aaas_v2&include=eJxLTEwsji8z0k_PyU9KzNEpriwuSc3VT0osTgUAg5EJ2Q — 200 — 62.5 KiB — 24 ms — h2https://www.aaas.org/core/assets/vendor/jquery/jquery.min.js?v=4.0.0-rc.1www.aaas.org/core/assets/vendor/jqu... https://www.aaas.org/core/assets/vendor/jquery/jquery.min.js?v=4.0.0-rc.1 — 200 — 31.7 KiB — 13 ms — h2https://assets.adobedtm.com/a48c09ba9d50/1e36ca10b673/launch-ea90f2ac46ad.min.jsassets.adobedtm.com/a48c09ba9d50/1e... https://assets.adobedtm.com/a48c09ba9d50/1e36ca10b673/launch-ea90f2ac46ad.min.js — 200 — 98.1 KiB — 31 ms — h2https://code.jquery.com/ui/1.13.0/jquery-ui.min.jscode.jquery.com/ui/1.13.0/jquery-ui... https://code.jquery.com/ui/1.13.0/jquery-ui.min.js — 200 — 66.7 KiB — 28 ms — h2https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300..800;1,300..800&display=swapfonts.googleapis.com/css2?family=Op... https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300..800;1,300..800&display=swap — 200 — 2.2 KiB — 86 ms — h2https://www.aaas.org/sites/default/files/styles/front_page_carousel/public/2026-04/MMF-Class2026-AAAS-HomeBanner.png?itok=TNf2LCYhwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/front_page_carousel/public/2026-04/MMF-Class2026-AAAS-HomeBanner.png?itok=TNf2LCYh — 200 — 36.3 KiB — 19 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Science_Homepage_04162026.jpg?itok=WGusOijIwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Science_Homepage_04162026.jpg?itok=WGusOijI — 200 — 32.9 KiB — 15 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2018-10/news_1019_journals_square.jpg?itok=vFEE6MCuwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2018-10/news_1019_journals_square.jpg?itok=vFEE6MCu — 200 — 39.1 KiB — 8 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/s3fs-public/news_media/News_0418_AAASCongress_teaser.jpg?itok=wiCRDLOPwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/s3fs-public/news_media/News_0418_AAASCongress_teaser.jpg?itok=wiCRDLOP — 200 — 25.3 KiB — 6 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/R%26D%20-%20PBR%20Web%20Tile%20-%20APR%202026%20-%20Round%202.png?itok=KYLtfhlXwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/R%26D%20-%20PBR%20Web%20Tile%20-%20APR%202026%20-%20Round%202.png?itok=KYLtfhlX — 200 — 14.7 KiB — 5 ms — h2https://code.jquery.com/jquery-3.6.4.min.jscode.jquery.com/jquery-3.6.4.min.js https://code.jquery.com/jquery-3.6.4.min.js — 200 — 30.4 KiB — 2 ms — h2https://www.aaas.org/sites/default/files/js/js_VapNRNoXd9QYusWCQLzrRkkd6SiZj36-H_4RU1rh5u4.js?scope=footer&delta=1&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyowww.aaas.org/sites/default/files/js... https://www.aaas.org/sites/default/files/js/js_VapNRNoXd9QYusWCQLzrRkkd6SiZj36-H_4RU1rh5u4.js?scope=footer&delta=1&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo — 200 — 30.2 KiB — 8 ms — h2https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.6/underscore-umd-min.jscdnjs.cloudflare.com/ajax/libs/unde... https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.6/underscore-umd-min.js — 200 — 7.3 KiB — 44 ms — h3https://www.aaas.org/sites/default/files/js/js_SytI1DevUZqbsifl6v4DWyz9fKcKO3zRuvs68WJj_j0.js?scope=footer&delta=3&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyowww.aaas.org/sites/default/files/js... https://www.aaas.org/sites/default/files/js/js_SytI1DevUZqbsifl6v4DWyz9fKcKO3zRuvs68WJj_j0.js?scope=footer&delta=3&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo — 200 — 39.5 KiB — 7 ms — h2https://weby.aaas.org/weby_bundle_v2.jsweby.aaas.org/weby_bundle_v2.js https://weby.aaas.org/weby_bundle_v2.js — 200 — 24.9 KiB — 62 ms — http/1.1blob:https://www.aaas.org/628ac7e2-dc00-488d-be85-29040e0ea7fcwww.aaas.org/628ac7e2-dc00-488d-be8... blob:https://www.aaas.org/628ac7e2-dc00-488d-be85-29040e0ea7fc — 200 — -1 B — 19 ms — blobhttps://www.aaas.org/sites/default/files/js/js_yVKPoGhK_-fapfI_W0AVQkNFrgm4aWh5uSgtCR8uyNY.js?scope=footer&delta=5&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyowww.aaas.org/sites/default/files/js... https://www.aaas.org/sites/default/files/js/js_yVKPoGhK_-fapfI_W0AVQkNFrgm4aWh5uSgtCR8uyNY.js?scope=footer&delta=5&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo — 200 — 1.3 KiB — 7 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/DRAFT%20-%20R%26D%20-%20PBR%20Web%20Tile%20-%20APR%202026.png?itok=N6jad9n4www.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/DRAFT%20-%20R%26D%20-%20PBR%20Web%20Tile%20-%20APR%202026.png?itok=N6jad9n4 — 200 — 25.8 KiB — 9 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2025-02/us%20capitol.png?itok=T3y9a4Lswww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2025-02/us%20capitol.png?itok=T3y9a4Ls — 200 — 17.9 KiB — 13 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AAAS-Fellows-2025_teaser.png?itok=ep-4G6_zwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AAAS-Fellows-2025_teaser.png?itok=ep-4G6_z — 200 — 16.0 KiB — 13 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Dr.%20Courtney%20Schreiber_Square%20highres%20headshot%20new2.jpg?itok=PkpqAUrywww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Dr.%20Courtney%20Schreiber_Square%20highres%20headshot%20new2.jpg?itok=PkpqAUry — 200 — 16.7 KiB — 13 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Fabio%20Rosa%20BII%20Science%20-%20square.jpg?itok=OHnceq0Awww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Fabio%20Rosa%20BII%20Science%20-%20square.jpg?itok=OHnceq0A — 200 — 16.7 KiB — 11 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AAAS-Learning-Hub-Launch-MemberUpdateTile.png?itok=2stH7rL2www.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AAAS-Learning-Hub-Launch-MemberUpdateTile.png?itok=2stH7rL2 — 200 — 13.0 KiB — 13 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-03/WCSJ%20Panela%20Photo%20-%20tile.jpeg?itok=PoPShMKWwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-03/WCSJ%20Panela%20Photo%20-%20tile.jpeg?itok=PoPShMKW — 200 — 34.2 KiB — 6 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AdobeStock_240490136_0.jpeg?itok=uTJPW5l_www.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AdobeStock_240490136_0.jpeg?itok=uTJPW5l_ — 200 — 7.9 KiB — 10 ms — h2
0 ms 500 ms 1.0 s FCP 1.1 s LCP 1.4 shttps://aaas.org// https://aaas.org/ — 301 — 207 B — 5 ms — h2https://www.aaas.org/www.aaas.org/ https://www.aaas.org/ — 200 — 26.1 KiB — 7 ms — h2https://www.aaas.org/sites/default/files/aaas/pre_osano_prod.jswww.aaas.org/sites/default/files/aa... https://www.aaas.org/sites/default/files/aaas/pre_osano_prod.js — 200 — 555 B — 9 ms — h2https://cmp.osano.com/HuPXR0mFqn/65f07145-79fc-4c5f-91b5-0fe679afddcc/osano.jscmp.osano.com/HuPXR0mFqn/65f07145-7... https://cmp.osano.com/HuPXR0mFqn/65f07145-79fc-4c5f-91b5-0fe679afddcc/osano.js — 200 — 71.9 KiB — 60 ms — h3https://www.aaas.org/sites/default/files/css/css_X44nJuq7WK8EaMaIccWsr-qJAZRK5CnZ4GGoAAjw8KE.css?delta=0&language=en&theme=aaas_v2&include=eJxLTEwsji8z0k_PyU9KzNEpriwuSc3VT0osTgUAg5EJ2Qwww.aaas.org/sites/default/files/cs... https://www.aaas.org/sites/default/files/css/css_X44nJuq7WK8EaMaIccWsr-qJAZRK5CnZ4GGoAAjw8KE.css?delta=0&language=en&theme=aaas_v2&include=eJxLTEwsji8z0k_PyU9KzNEpriwuSc3VT0osTgUAg5EJ2Q — 200 — 4.4 KiB — 11 ms — h2https://www.aaas.org/sites/default/files/css/css_x57-XDHutk6povG07wlJbji7BXEbrZEpRnJSmBgh3K0.css?delta=1&language=en&theme=aaas_v2&include=eJxLTEwsji8z0k_PyU9KzNEpriwuSc3VT0osTgUAg5EJ2Qwww.aaas.org/sites/default/files/cs... https://www.aaas.org/sites/default/files/css/css_x57-XDHutk6povG07wlJbji7BXEbrZEpRnJSmBgh3K0.css?delta=1&language=en&theme=aaas_v2&include=eJxLTEwsji8z0k_PyU9KzNEpriwuSc3VT0osTgUAg5EJ2Q — 200 — 62.5 KiB — 24 ms — h2https://www.aaas.org/core/assets/vendor/jquery/jquery.min.js?v=4.0.0-rc.1www.aaas.org/core/assets/vendor/jqu... https://www.aaas.org/core/assets/vendor/jquery/jquery.min.js?v=4.0.0-rc.1 — 200 — 31.7 KiB — 13 ms — h2https://assets.adobedtm.com/a48c09ba9d50/1e36ca10b673/launch-ea90f2ac46ad.min.jsassets.adobedtm.com/a48c09ba9d50/1e... https://assets.adobedtm.com/a48c09ba9d50/1e36ca10b673/launch-ea90f2ac46ad.min.js — 200 — 98.1 KiB — 31 ms — h2https://code.jquery.com/ui/1.13.0/jquery-ui.min.jscode.jquery.com/ui/1.13.0/jquery-ui... https://code.jquery.com/ui/1.13.0/jquery-ui.min.js — 200 — 66.7 KiB — 28 ms — h2https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300..800;1,300..800&display=swapfonts.googleapis.com/css2?family=Op... https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300..800;1,300..800&display=swap — 200 — 2.2 KiB — 86 ms — h2https://www.aaas.org/sites/default/files/styles/front_page_carousel/public/2026-04/MMF-Class2026-AAAS-HomeBanner.png?itok=TNf2LCYhwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/front_page_carousel/public/2026-04/MMF-Class2026-AAAS-HomeBanner.png?itok=TNf2LCYh — 200 — 36.3 KiB — 19 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Science_Homepage_04162026.jpg?itok=WGusOijIwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Science_Homepage_04162026.jpg?itok=WGusOijI — 200 — 32.9 KiB — 15 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2018-10/news_1019_journals_square.jpg?itok=vFEE6MCuwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2018-10/news_1019_journals_square.jpg?itok=vFEE6MCu — 200 — 39.1 KiB — 8 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/s3fs-public/news_media/News_0418_AAASCongress_teaser.jpg?itok=wiCRDLOPwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/s3fs-public/news_media/News_0418_AAASCongress_teaser.jpg?itok=wiCRDLOP — 200 — 25.3 KiB — 6 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/R%26D%20-%20PBR%20Web%20Tile%20-%20APR%202026%20-%20Round%202.png?itok=KYLtfhlXwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/R%26D%20-%20PBR%20Web%20Tile%20-%20APR%202026%20-%20Round%202.png?itok=KYLtfhlX — 200 — 14.7 KiB — 5 ms — h2https://code.jquery.com/jquery-3.6.4.min.jscode.jquery.com/jquery-3.6.4.min.js https://code.jquery.com/jquery-3.6.4.min.js — 200 — 30.4 KiB — 2 ms — h2https://www.aaas.org/sites/default/files/js/js_VapNRNoXd9QYusWCQLzrRkkd6SiZj36-H_4RU1rh5u4.js?scope=footer&delta=1&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyowww.aaas.org/sites/default/files/js... https://www.aaas.org/sites/default/files/js/js_VapNRNoXd9QYusWCQLzrRkkd6SiZj36-H_4RU1rh5u4.js?scope=footer&delta=1&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo — 200 — 30.2 KiB — 8 ms — h2https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.6/underscore-umd-min.jscdnjs.cloudflare.com/ajax/libs/unde... https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.6/underscore-umd-min.js — 200 — 7.3 KiB — 44 ms — h3https://www.aaas.org/sites/default/files/js/js_SytI1DevUZqbsifl6v4DWyz9fKcKO3zRuvs68WJj_j0.js?scope=footer&delta=3&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyowww.aaas.org/sites/default/files/js... https://www.aaas.org/sites/default/files/js/js_SytI1DevUZqbsifl6v4DWyz9fKcKO3zRuvs68WJj_j0.js?scope=footer&delta=3&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo — 200 — 39.5 KiB — 7 ms — h2https://weby.aaas.org/weby_bundle_v2.jsweby.aaas.org/weby_bundle_v2.js https://weby.aaas.org/weby_bundle_v2.js — 200 — 24.9 KiB — 62 ms — http/1.1blob:https://www.aaas.org/628ac7e2-dc00-488d-be85-29040e0ea7fcwww.aaas.org/628ac7e2-dc00-488d-be8... blob:https://www.aaas.org/628ac7e2-dc00-488d-be85-29040e0ea7fc — 200 — -1 B — 19 ms — blobhttps://www.aaas.org/sites/default/files/js/js_yVKPoGhK_-fapfI_W0AVQkNFrgm4aWh5uSgtCR8uyNY.js?scope=footer&delta=5&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyowww.aaas.org/sites/default/files/js... https://www.aaas.org/sites/default/files/js/js_yVKPoGhK_-fapfI_W0AVQkNFrgm4aWh5uSgtCR8uyNY.js?scope=footer&delta=5&language=en&theme=aaas_v2&include=eJxNzNEOgyAMheEXGjHZC5EDbQBTV1dAw9vPZcZ52b85H4Dqt-cE0sDUFjfXB84We226uBqtrO2fk2iAXOf87mzD9eIyg9iux85hfDlCg2CwTYEztqJ2b5llPUY_xZPur2QHc7JeOCGODzgTPyo — 200 — 1.3 KiB — 7 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/DRAFT%20-%20R%26D%20-%20PBR%20Web%20Tile%20-%20APR%202026.png?itok=N6jad9n4www.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/DRAFT%20-%20R%26D%20-%20PBR%20Web%20Tile%20-%20APR%202026.png?itok=N6jad9n4 — 200 — 25.8 KiB — 9 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2025-02/us%20capitol.png?itok=T3y9a4Lswww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2025-02/us%20capitol.png?itok=T3y9a4Ls — 200 — 17.9 KiB — 13 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AAAS-Fellows-2025_teaser.png?itok=ep-4G6_zwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AAAS-Fellows-2025_teaser.png?itok=ep-4G6_z — 200 — 16.0 KiB — 13 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Dr.%20Courtney%20Schreiber_Square%20highres%20headshot%20new2.jpg?itok=PkpqAUrywww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Dr.%20Courtney%20Schreiber_Square%20highres%20headshot%20new2.jpg?itok=PkpqAUry — 200 — 16.7 KiB — 13 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Fabio%20Rosa%20BII%20Science%20-%20square.jpg?itok=OHnceq0Awww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-04/Fabio%20Rosa%20BII%20Science%20-%20square.jpg?itok=OHnceq0A — 200 — 16.7 KiB — 11 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AAAS-Learning-Hub-Launch-MemberUpdateTile.png?itok=2stH7rL2www.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AAAS-Learning-Hub-Launch-MemberUpdateTile.png?itok=2stH7rL2 — 200 — 13.0 KiB — 13 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-03/WCSJ%20Panela%20Photo%20-%20tile.jpeg?itok=PoPShMKWwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-03/WCSJ%20Panela%20Photo%20-%20tile.jpeg?itok=PoPShMKW — 200 — 34.2 KiB — 6 ms — h2https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AdobeStock_240490136_0.jpeg?itok=uTJPW5l_www.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/square/public/2026-03/AdobeStock_240490136_0.jpeg?itok=uTJPW5l_ — 200 — 7.9 KiB — 10 ms — h2https://www.aaas.org/sites/default/files/styles/large/public/2026-02/SNAP%20collage_Square_1080x1080.png?itok=tSStFAJ8www.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/large/public/2026-02/SNAP%20collage_Square_1080x1080.png?itok=tSStFAJ8 — 200 — 29.0 KiB — 8 ms — h2https://www.aaas.org/sites/default/files/styles/large/public/2025-12/Paula%20R.%20Buchanan.jpg?itok=wLC3h6WAwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/large/public/2025-12/Paula%20R.%20Buchanan.jpg?itok=wLC3h6WA — 200 — 26.4 KiB — 9 ms — h2https://www.aaas.org/sites/default/files/2026-04/Robert%20Putnam.jpgwww.aaas.org/sites/default/files/20... https://www.aaas.org/sites/default/files/2026-04/Robert%20Putnam.jpg — 200 — 20.9 KiB — 5 ms — h2https://www.aaas.org/sites/default/files/styles/footer_features/public/2023-10/1848%20Society%20homepage_0.png?itok=MmOWMfOUwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/footer_features/public/2023-10/1848%20Society%20homepage_0.png?itok=MmOWMfOU — 200 — 10.7 KiB — 8 ms — h2https://www.aaas.org/sites/default/files/styles/footer_features/public/2023-10/Monroes%20homepage.png?itok=J80UzRIOwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/footer_features/public/2023-10/Monroes%20homepage.png?itok=J80UzRIO — 200 — 17.0 KiB — 7 ms — h2https://www.aaas.org/sites/default/files/styles/footer_features/public/2025-03/Jean%20Taylor%20Homepage%201.jpg?itok=WA0TJzgfwww.aaas.org/sites/default/files/st... https://www.aaas.org/sites/default/files/styles/footer_features/public/2025-03/Jean%20Taylor%20Homepage%201.jpg?itok=WA0TJzgf — 200 — 18.2 KiB — 6 ms — h2https://www.aaas.org/themes/custom/aaas_v2/assets/images/common/pattern-circles-full.svgwww.aaas.org/themes/custom/aaas_v2/... https://www.aaas.org/themes/custom/aaas_v2/assets/images/common/pattern-circles-full.svg — 200 — 9.2 KiB — 5 ms — h2https://www.aaas.org/themes/custom/aaas_v2/assets/images/common/twitterx-icon-white.svgwww.aaas.org/themes/custom/aaas_v2/... https://www.aaas.org/themes/custom/aaas_v2/assets/images/common/twitterx-icon-white.svg — 200 — 699 B — 5 ms — h2https://www.aaas.org/themes/custom/aaas_v2/assets/images/common/aaas-member-community-white.svgwww.aaas.org/themes/custom/aaas_v2/... https://www.aaas.org/themes/custom/aaas_v2/assets/images/common/aaas-member-community-white.svg — 200 — 1.1 KiB — 6 ms — h2https://www.aaas.org/themes/custom/aaas_v2/assets/images/common/bluesky_media_kit_logo_white_square.svgwww.aaas.org/themes/custom/aaas_v2/... https://www.aaas.org/themes/custom/aaas_v2/assets/images/common/bluesky_media_kit_logo_white_square.svg — 200 — 760 B — 5 ms — h2https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2fonts.gstatic.com/s/opensans/v44/me... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 200 — 42.0 KiB — 66 ms — h3https://fonts.gstatic.com/s/opensans/v44/memtYaGs126MiZpBA-UFUIcVXSCEkx2cmqvXlWqWuU6FxZCJgg.woff2fonts.gstatic.com/s/opensans/v44/me... https://fonts.gstatic.com/s/opensans/v44/memtYaGs126MiZpBA-UFUIcVXSCEkx2cmqvXlWqWuU6FxZCJgg.woff2 — 200 — 44.0 KiB — 70 ms — h3https://www.aaas.org/themes/custom/aaas_v2/assets/fonts/icomoon.ttf?2017_11_28_001=www.aaas.org/themes/custom/aaas_v2/... https://www.aaas.org/themes/custom/aaas_v2/assets/fonts/icomoon.ttf?2017_11_28_001= — 200 — 104.1 KiB — 9 ms — h2https://cmp.osano.com/cmp.osano.com/ https://cmp.osano.com/ — 200 — 1.1 KiB — 38 ms — h3https://www.aaas.org/themes/custom/aaas_v2/assets/images/favicon.icowww.aaas.org/themes/custom/aaas_v2/... https://www.aaas.org/themes/custom/aaas_v2/assets/images/favicon.ico — 200 — 3.3 KiB — 9 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 368ms · 137KB · €2/mo
www.aaas.org
Other
Optional
Execution 146ms
Transfer 26 KB
Monthly Cost €1/mo
cmp.osano.com
Other
Optional
Execution 106ms
Transfer 72 KB
Unused 33%
Monthly Cost €1/mo
www.aaas.org
Other
Optional
Execution 59ms
Transfer 39 KB
Monthly Cost €0/mo
Unattributable
Other
Optional
Execution 57ms
Transfer 0 KB
Monthly Cost €0/mo

100% 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

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.

Send Feedback