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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
80
GRADE
B
FIX
4
REVIEW
2
PASS
9
INFO
2

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

Mobile Desktop
59
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
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.
100
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.

4.52 s

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

6.55 s

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

316 ms

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

0.023

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

4.52 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.

7.31 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
9 PASS 2 REVIEW 4 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 (1.3 MiB of 1.3 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
JS Execution Cost
Action
2573ms total JS execution
FIX
2573ms total JS execution
Warning::
https://www.scientificamerican.com/: 678ms CPU time
Warning::
Unattributable: 478ms CPU time
Warning::
https://www.scientificamerican.com/static/chunks/e...: 367ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-5FL...: 345ms CPU time
Info::
https://www.scientificamerican.com/static/chunks/v...: 242ms CPU time
Warning::
Third-party scripts: 2573ms (100% of total)

Main Thread Breakdown

Script Evaluation 38% Other 29% Style & Layout 19% Script Parsing & Compilation 5% Parse HTML & CSS 3% Rendering 3%
ScriptTotalScriptingParse/CompileParty
https://www.scientificamerican.com/678ms38ms50ms3rd
Unattributable478ms10ms0ms3rd
https://www.scientificamerican.com/static/chunks/errorboundary-CJyx5mlo.js367ms163ms0ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-5FLM662345ms252ms65ms3rd
https://www.scientificamerican.com/static/chunks/vendor-react-Dqw-xFm4.js242ms236ms2ms3rd
https://www.scientificamerican.com/static/chunks/sciam-B4Xuwe4e.js234ms219ms1ms3rd
https://cmp.springernature.com/production_live/en/consent-bundle-144-10.js228ms80ms17ms3rd
D
JS Bundles
Action
40 scripts, 206 KB unused
FIX
40 scripts, 206 KB unused
Warning::
https://www.scientificamerican.com/static/chunks/i...: 81 KB unused (66%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-5FL...: 76 KB unused (48%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.scientificamerican.com/static/chunks/v...: 48 KB unused (41%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.scientificamerican.com/sciads/sciads.j...: unminified — 7 KB could be saved
Info::
Total unused JavaScript: 206 KB
206 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.scientificamerican.com/static/chunks/index-DdtKFinu.js126 KB81 KB (66%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-5FLM662160 KB76 KB (48%)✓3rd
https://www.scientificamerican.com/static/chunks/vendor-react-Dqw-xFm4.js119 KB48 KB (41%)✓3rd
https://www.scientificamerican.com/static/chunks/use-cart-DTnLA9u2.js2 KB—✓3rd
https://www.scientificamerican.com/sciads/sciads.js24 KB—✗3rd
https://www.scientificamerican.com/static/chunks/use-auth-CEBA_iny.js11 KB—✓3rd
https://www.scientificamerican.com/static/chunks/datalayer-BUxHYK4X.js1 KB—✓3rd
https://www.scientificamerican.com/static/chunks/use-user-C_02cgLh.js2 KB—✓3rd
https://www.scientificamerican.com/static/chunks/DefaultLayout-DCwTEK0T.js2 KB—✓3rd
https://www.scientificamerican.com/static/chunks/use-plan-BmlcyOG8.js1 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

D
Page Weight Inventory
Action
81 resources · 1.3 MB · 206 KB savings available
FIX
81 resources · 1.3 MB · 206 KB savings available
Warning::
Page weight 313 KB over 1MB target
Got: 1.3 MB Expected: ≤ 1 MB
Info::
~206 KB of savings available
Warning::
80 third-party resources (100% of weight)
81 resources · 1.3 MiB · 80 third-party 313.3 KiB over 1MB target
JavaScript 46% · 611.5 KiB
Image 30% · 405.2 KiB
Font 16% · 215.4 KiB
Document 5% · 67.6 KiB
CSS 3% · 35.8 KiB
Other 0% · 1.8 KiB

~205.5 KiB of savings available

Remove unused JavaScript: 205.5 KiB
B
Page Weight Budget
1.3 MB transferred, 81 requests
REVIEW
1.3 MB transferred, 81 requests
Info::
Page weighs 2.8 MB (1.3 MB transferred)
Warning::
JavaScript is 612 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 612 KB
Info::
Fonts are 215 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 215 KB
Info::
81 HTTP requests
Info::
Estimated 0.27 g CO2 per page load
1.3 MB / 2.4 MB budget
1.3 MB transferred
81 requests
0.27 g CO2 per page load
JavaScript 611.5 KiB 46%
Images 403.8 KiB 30%
Fonts 215.4 KiB 16%
HTML 67.6 KiB 5%
CSS 35.8 KiB 3%
Other 1.9 KiB 0%
Other 1.3 KiB 0%
0 2.4 MB 4.9 MB
Under budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

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
Image Optimization
16 images, 0 KB saveable
PASS
16 images, 0 KB saveable
Warning::
https://static.scientificamerican.com/dam/asset/ff... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://static.scientificamerican.com/dam/m/ff32f9... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
16 images 404 KB
0 oversized -0 KB
1 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

A+
Font Loading
5 fonts (215 KB)
PASS
5 fonts (215 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

215 KB total

Render-blocking

0

of 5

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s FCP 4.5 s LCP 6.5 shttps://www.scientificamerican.com/static/assets/GT-America-Standard-Regular-C7OkZNy_.woff2GT-America-Standard-Reg... https://www.scientificamerican.com/static/assets/GT-America-Standard-Regular-C7OkZNy_.woff2 — 57.7 KiB — 24 ms — font-display: swaphttps://www.scientificamerican.com/static/assets/GT-America-Standard-Bold-Gn4hHfn_.woff2GT-America-Standard-Bol... https://www.scientificamerican.com/static/assets/GT-America-Standard-Bold-Gn4hHfn_.woff2 — 61.7 KiB — 30 ms — font-display: swaphttps://www.scientificamerican.com/static/assets/GT-America-Standard-Bold-Italic-g-lhaQmf.woff2GT-America-Standard-Bol... https://www.scientificamerican.com/static/assets/GT-America-Standard-Bold-Italic-g-lhaQmf.woff2 — 62.5 KiB — 34 ms — font-display: swaphttps://www.scientificamerican.com/static/assets/Crimson%20Text-reg-BBt56E4f.woff2Crimson%20Text-reg-BBt5... https://www.scientificamerican.com/static/assets/Crimson%20Text-reg-BBt56E4f.woff2 — 16.5 KiB — 33 ms — font-display: swaphttps://www.scientificamerican.com/static/assets/Crimson%20Text-reg_it-s1By9Gv_.woff2Crimson%20Text-reg_it-s... https://www.scientificamerican.com/static/assets/Crimson%20Text-reg_it-s1By9Gv_.woff2 — 17.1 KiB — 33 ms — font-display: swap
GT-America-Standard-Reg... woff2 swap
Size 58 KB
Load time 24 ms
Start 260 ms
Risk FOUT — text flashes from fallback to web font
GT-America-Standard-Bol... woff2 swap
Size 62 KB
Load time 30 ms
Start 262 ms
Risk FOUT — text flashes from fallback to web font
GT-America-Standard-Bol... woff2 swap
Size 63 KB
Load time 34 ms
Start 263 ms
Risk FOUT — text flashes from fallback to web font
Crimson%20Text-reg-BBt5... woff2 swap
Size 16 KB
Load time 33 ms
Start 264 ms
Risk FOUT — text flashes from fallback to web font
Crimson%20Text-reg_it-s... woff2 swap
Size 17 KB
Load time 33 ms
Start 265 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
6 hints, 0 missing preconnects
PASS
6 hints, 0 missing preconnects
Info::
Page uses 6 resource hint(s)

Current Resource Hints

preconnect
1
preload
5
dns-prefetch
—
prefetch
—

6 resource hints configured

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
HTTP Caching
max-age=86400 (1 day)
PASS
max-age=86400 (1 day)
Info::
Cache-Control header is set
Got: max-age=86400
Info::
Effective TTL: 1 day (max-age=86400)
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

max-age=86400

DirectiveValueMeaning
max-age86400Cache for 1 day
Effective TTL: 86400 seconds
Network Waterfall
81 requests over 725ms
INFO
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s FCP 4.5 s LCP 6.5 shttps://scientificamerican.com// https://scientificamerican.com/ — 301 — 572 B — 13 ms — h2https://www.scientificamerican.com/www.scientificamerican.com/ https://www.scientificamerican.com/ — 200 — 67.6 KiB — 16 ms — h2https://www.scientificamerican.com/static/bundle.D4myR-c2.jswww.scientificamerican.com/static/b... https://www.scientificamerican.com/static/bundle.D4myR-c2.js — 200 — 30.6 KiB — 46 ms — h2https://www.scientificamerican.com/static/chunks/preload-helper-MnokBkrb.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/preload-helper-MnokBkrb.js — 200 — 1.0 KiB — 19 ms — h2https://www.scientificamerican.com/static/chunks/vendor-react-Dqw-xFm4.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/vendor-react-Dqw-xFm4.js — 200 — 118.6 KiB — 124 ms — h2https://www.scientificamerican.com/static/chunks/sciam-B4Xuwe4e.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/sciam-B4Xuwe4e.js — 200 — 11.5 KiB — 48 ms — h2https://www.scientificamerican.com/static/chunks/errorboundary-CJyx5mlo.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/errorboundary-CJyx5mlo.js — 200 — 12.8 KiB — 102 ms — h2https://www.scientificamerican.com/static/chunks/use-auth-CEBA_iny.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-auth-CEBA_iny.js — 200 — 10.9 KiB — 91 ms — h2https://www.scientificamerican.com/static/chunks/datalayer-BUxHYK4X.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/datalayer-BUxHYK4X.js — 200 — 660 B — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-user-C_02cgLh.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-user-C_02cgLh.js — 200 — 1.9 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-chargebee-BC7jUIYG.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-chargebee-BC7jUIYG.js — 200 — 4.4 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-plan-BmlcyOG8.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-plan-BmlcyOG8.js — 200 — 1.1 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-cart-DTnLA9u2.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-cart-DTnLA9u2.js — 200 — 2.1 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-consent-BXGXXq97.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-consent-BXGXXq97.js — 200 — 1.8 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/tally-DbwAMvgb.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/tally-DbwAMvgb.js — 200 — 2.1 KiB — 73 ms — h2https://www.scientificamerican.com/static/chunks/use-count-DLTx8ng8.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-count-DLTx8ng8.js — 200 — 1.4 KiB — 73 ms — h2https://www.scientificamerican.com/static/chunks/utils-QDS1VHJ5.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/utils-QDS1VHJ5.js — 200 — 1.9 KiB — 73 ms — h2https://www.scientificamerican.com/static/chunks/provider-DWo_EWuS.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/provider-DWo_EWuS.js — 200 — 1.3 KiB — 74 ms — h2https://www.scientificamerican.com/static/chunks/useOverlay-BlofETwt.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/useOverlay-BlofETwt.js — 200 — 940 B — 74 ms — h2https://www.scientificamerican.com/static/chunks/gtm-tjz2E76q.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/gtm-tjz2E76q.js — 200 — 2.3 KiB — 73 ms — h2https://www.scientificamerican.com/static/assets/bundle-Bu8EBeue.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/bundle-Bu8EBeue.css — 200 — 3.3 KiB — 38 ms — h2https://www.scientificamerican.com/static/assets/Input-C57946EV.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/Input-C57946EV.css — 200 — 1.6 KiB — 38 ms — h2https://www.scientificamerican.com/static/assets/DynamicLabelInput-DwXtCBSS.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/DynamicLabelInput-DwXtCBSS.css — 200 — 656 B — 64 ms — h2https://www.scientificamerican.com/static/assets/TalkIcon-CYQQg01-.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/TalkIcon-CYQQg01-.css — 200 — 405 B — 38 ms — h2https://www.scientificamerican.com/static/assets/ArticleList-CbosH0t6.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/ArticleList-CbosH0t6.css — 200 — 744 B — 37 ms — h2https://www.scientificamerican.com/static/assets/IssuePage-8lYoxDef.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/IssuePage-8lYoxDef.css — 200 — 2.4 KiB — 63 ms — h2https://www.scientificamerican.com/static/assets/Kicker-BuYKkL60.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/Kicker-BuYKkL60.css — 200 — 1.0 KiB — 37 ms — h2https://www.scientificamerican.com/static/assets/index--Rm_Dt2j.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/index--Rm_Dt2j.css — 200 — 11.7 KiB — 47 ms — h2https://www.scientificamerican.com/static/assets/ArticleDisplay-CkAgyHRP.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/ArticleDisplay-CkAgyHRP.css — 200 — 1.3 KiB — 37 ms — h2https://www.scientificamerican.com/static/assets/ExploreTopics-BfzsiatO.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/ExploreTopics-BfzsiatO.css — 200 — 1.3 KiB — 37 ms — h2
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s FCP 4.5 s LCP 6.5 shttps://scientificamerican.com// https://scientificamerican.com/ — 301 — 572 B — 13 ms — h2https://www.scientificamerican.com/www.scientificamerican.com/ https://www.scientificamerican.com/ — 200 — 67.6 KiB — 16 ms — h2https://www.scientificamerican.com/static/bundle.D4myR-c2.jswww.scientificamerican.com/static/b... https://www.scientificamerican.com/static/bundle.D4myR-c2.js — 200 — 30.6 KiB — 46 ms — h2https://www.scientificamerican.com/static/chunks/preload-helper-MnokBkrb.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/preload-helper-MnokBkrb.js — 200 — 1.0 KiB — 19 ms — h2https://www.scientificamerican.com/static/chunks/vendor-react-Dqw-xFm4.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/vendor-react-Dqw-xFm4.js — 200 — 118.6 KiB — 124 ms — h2https://www.scientificamerican.com/static/chunks/sciam-B4Xuwe4e.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/sciam-B4Xuwe4e.js — 200 — 11.5 KiB — 48 ms — h2https://www.scientificamerican.com/static/chunks/errorboundary-CJyx5mlo.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/errorboundary-CJyx5mlo.js — 200 — 12.8 KiB — 102 ms — h2https://www.scientificamerican.com/static/chunks/use-auth-CEBA_iny.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-auth-CEBA_iny.js — 200 — 10.9 KiB — 91 ms — h2https://www.scientificamerican.com/static/chunks/datalayer-BUxHYK4X.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/datalayer-BUxHYK4X.js — 200 — 660 B — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-user-C_02cgLh.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-user-C_02cgLh.js — 200 — 1.9 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-chargebee-BC7jUIYG.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-chargebee-BC7jUIYG.js — 200 — 4.4 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-plan-BmlcyOG8.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-plan-BmlcyOG8.js — 200 — 1.1 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-cart-DTnLA9u2.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-cart-DTnLA9u2.js — 200 — 2.1 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/use-consent-BXGXXq97.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-consent-BXGXXq97.js — 200 — 1.8 KiB — 72 ms — h2https://www.scientificamerican.com/static/chunks/tally-DbwAMvgb.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/tally-DbwAMvgb.js — 200 — 2.1 KiB — 73 ms — h2https://www.scientificamerican.com/static/chunks/use-count-DLTx8ng8.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/use-count-DLTx8ng8.js — 200 — 1.4 KiB — 73 ms — h2https://www.scientificamerican.com/static/chunks/utils-QDS1VHJ5.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/utils-QDS1VHJ5.js — 200 — 1.9 KiB — 73 ms — h2https://www.scientificamerican.com/static/chunks/provider-DWo_EWuS.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/provider-DWo_EWuS.js — 200 — 1.3 KiB — 74 ms — h2https://www.scientificamerican.com/static/chunks/useOverlay-BlofETwt.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/useOverlay-BlofETwt.js — 200 — 940 B — 74 ms — h2https://www.scientificamerican.com/static/chunks/gtm-tjz2E76q.jswww.scientificamerican.com/static/c... https://www.scientificamerican.com/static/chunks/gtm-tjz2E76q.js — 200 — 2.3 KiB — 73 ms — h2https://www.scientificamerican.com/static/assets/bundle-Bu8EBeue.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/bundle-Bu8EBeue.css — 200 — 3.3 KiB — 38 ms — h2https://www.scientificamerican.com/static/assets/Input-C57946EV.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/Input-C57946EV.css — 200 — 1.6 KiB — 38 ms — h2https://www.scientificamerican.com/static/assets/DynamicLabelInput-DwXtCBSS.csswww.scientificamerican.com/static/a... https://www.scientificamerican.com/static/assets/DynamicLabelInput-DwXtCBSS.css — 200 — 656 B — 64 ms — h2https://www.scientificamerican.com/static/assets/TalkIcon-CYQQg01-.csswww.scientificamerican.com/static/a... 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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 2573ms · 408KB · €45/mo
www.scientificamerican.com
Other
Costly
Execution 678ms
Transfer 68 KB
Monthly Cost €12/mo
Unattributable
Other
Costly
Execution 478ms
Transfer 0 KB
Monthly Cost €8/mo
www.scientificamerican.com
Other
Costly
Execution 367ms
Transfer 13 KB
Monthly Cost €6/mo
Google Tag Manager
Tag Manager
Costly
Execution 345ms
Transfer 160 KB
Unused 48%
Monthly Cost €6/mo
www.scientificamerican.com
Other
Costly
Execution 242ms
Transfer 119 KB
Unused 41%
Monthly Cost €4/mo
www.scientificamerican.com
Other
Costly
Execution 234ms
Transfer 12 KB
Monthly Cost €4/mo
cmp.springernature.com
Other
Costly
Execution 228ms
Transfer 38 KB
Monthly Cost €4/mo

These scripts may cost more than they're worth

  • www.scientificamerican.com adds 678ms and costs ~€12/month
  • Unattributable adds 478ms and costs ~€8/month
  • www.scientificamerican.com adds 367ms and costs ~€6/month
  • Google Tag Manager adds 345ms and costs ~€6/month
  • www.scientificamerican.com adds 242ms and costs ~€4/month
  • www.scientificamerican.com adds 234ms and costs ~€4/month
  • cmp.springernature.com adds 228ms and costs ~€4/month

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

www.scientificamerican.com takes 678ms 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

Unattributable takes 478ms 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.scientificamerican.com takes 367ms 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

Google Tag Manager takes 345ms 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.scientificamerican.com takes 242ms 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.scientificamerican.com takes 234ms 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

cmp.springernature.com takes 228ms 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

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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