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https://smashingmagazine.com

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
87
GRADE
B
FIX
2
REVIEW
4
PASS
7
INFO
2

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

Mobile Desktop
98
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
92
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.

780 ms

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

1.07 s

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

26 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.

780 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

1.07 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 (445.0 KiB of 445.2 KiB)
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.

C
Image Optimization
Action
25 images, 0 KB saveable
REVIEW
25 images, 0 KB saveable
Warning::
https://www.smashingmagazine.com/images/logo.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.smashingmagazine.com/images/smashing-c... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
25 images 76 KB
0 oversized -0 KB
14 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

B
JS Execution Cost
649ms total JS execution
REVIEW
649ms total JS execution
Warning::
https://www.smashingmagazine.com/: 472ms CPU time
Info::
Unattributable: 104ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-CXX3...: 73ms CPU time
Warning::
Third-party scripts: 649ms (100% of total)

Main Thread Breakdown

Style & Layout 45% Other 30% Script Evaluation 12% Rendering 5% Parse HTML & CSS 4% Script Parsing & Compilation 4%
ScriptTotalScriptingParse/CompileParty
https://www.smashingmagazine.com/472ms19ms8ms3rd
Unattributable104ms5ms0ms3rd
https://www.googletagmanager.com/gtag/js?id=G-CXX395KXNG73ms52ms17ms3rd
B
JS Bundles
3 scripts, 84 KB unused
REVIEW
3 scripts, 84 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-CXX3...: 84 KB unused (56%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 84 KB
84 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-CXX395KXNG150 KB84 KB (56%)✓3rd
https://www.smashingmagazine.com/js/nav-v2.js1 KB—✓3rd
https://www.smashingmagazine.com/.netlify/scripts/rum4 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

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Page Weight Budget
445 KB transferred, 43 requests
PASS
445 KB transferred, 43 requests
Info::
Page weighs 1.3 MB (445 KB transferred)
Info::
43 HTTP requests
Info::
Estimated 0.09 g CO2 per page load
445 KB / 2.4 MB budget
445 KB transferred
43 requests
0.09 g CO2 per page load
JavaScript 155.0 KiB 35%
Images 75.6 KiB 17%
HTML 75.2 KiB 17%
CSS 72.1 KiB 16%
Fonts 64.9 KiB 15%
Other 2.0 KiB 0%
Other 367 B 0%
0 2.4 MB 4.9 MB
Under budget
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
4 fonts (65 KB)
PASS
4 fonts (65 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

65 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 500 ms 1.0 s FCP 780 ms LCP 1.1 shttps://www.smashingmagazine.com/fonts/ElenaWebRegular/ElenaWebRegular-subset-v2.woff2ElenaWebRegular-subset-... https://www.smashingmagazine.com/fonts/ElenaWebRegular/ElenaWebRegular-subset-v2.woff2 — 16.6 KiB — 31 ms — font-display: swaphttps://www.smashingmagazine.com/fonts/ElenaWebBold/ElenaWebBold-subset-v2.woff2ElenaWebBold-subset-v2.... https://www.smashingmagazine.com/fonts/ElenaWebBold/ElenaWebBold-subset-v2.woff2 — 16.9 KiB — 36 ms — font-display: swaphttps://www.smashingmagazine.com/fonts/MijaBold/Mija_Bold-webfont-subset-v2.woff2Mija_Bold-webfont-subse... https://www.smashingmagazine.com/fonts/MijaBold/Mija_Bold-webfont-subset-v2.woff2 — 14.2 KiB — 38 ms — font-display: swaphttps://www.smashingmagazine.com/fonts/ElenaWebRegularItalic/ElenaWebRegularItalic-subset-v2.woff2ElenaWebRegularItalic-s... https://www.smashingmagazine.com/fonts/ElenaWebRegularItalic/ElenaWebRegularItalic-subset-v2.woff2 — 17.1 KiB — 22 ms — font-display: swap
ElenaWebRegular-subset-... woff2 swap
Size 17 KB
Load time 31 ms
Start 90 ms
Risk FOUT — text flashes from fallback to web font
ElenaWebBold-subset-v2.... woff2 swap
Size 17 KB
Load time 36 ms
Start 91 ms
Risk FOUT — text flashes from fallback to web font
Mija_Bold-webfont-subse... woff2 swap
Size 14 KB
Load time 38 ms
Start 91 ms
Risk FOUT — text flashes from fallback to web font
ElenaWebRegularItalic-s... woff2 swap
Size 17 KB
Load time 22 ms
Start 92 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
Page Weight Inventory
43 resources · 445 KB · 84 KB savings available
PASS
43 resources · 445 KB · 84 KB savings available
Info::
Within 1MB page-weight target
Got: 445 KB
Info::
~84 KB of savings available
Warning::
42 third-party resources (100% of weight)
43 resources · 445.2 KiB · 42 third-party Within 1MB page-weight target
JavaScript 35% · 155.0 KiB
Image 17% · 77.5 KiB
Document 17% · 75.2 KiB
CSS 16% · 72.1 KiB
Font 15% · 64.9 KiB
Other 0% · 535 B

~84.3 KiB of savings available

Remove unused JavaScript: 84.3 KiB
Network Waterfall
43 requests over 745ms
INFO
0 ms 500 ms 1.0 s FCP 780 ms LCP 1.1 shttps://smashingmagazine.com// https://smashingmagazine.com/ — 301 — 168 B — 35 ms — h2https://www.smashingmagazine.com/www.smashingmagazine.com/ https://www.smashingmagazine.com/ — 200 — 75.2 KiB — 40 ms — h2https://www.smashingmagazine.com/js/nav-v2.jswww.smashingmagazine.com/js/nav-v2.... https://www.smashingmagazine.com/js/nav-v2.js — 200 — 828 B — 15 ms — h2https://www.smashingmagazine.com/fonts/ElenaWebRegular/ElenaWebRegular-subset-v2.woff2www.smashingmagazine.com/fonts/Elen... https://www.smashingmagazine.com/fonts/ElenaWebRegular/ElenaWebRegular-subset-v2.woff2 — 200 — 16.6 KiB — 31 ms — h2https://www.smashingmagazine.com/fonts/ElenaWebBold/ElenaWebBold-subset-v2.woff2www.smashingmagazine.com/fonts/Elen... https://www.smashingmagazine.com/fonts/ElenaWebBold/ElenaWebBold-subset-v2.woff2 — 200 — 16.9 KiB — 36 ms — h2https://www.smashingmagazine.com/fonts/MijaBold/Mija_Bold-webfont-subset-v2.woff2www.smashingmagazine.com/fonts/Mija... https://www.smashingmagazine.com/fonts/MijaBold/Mija_Bold-webfont-subset-v2.woff2 — 200 — 14.2 KiB — 38 ms — h2https://www.smashingmagazine.com/fonts/ElenaWebRegularItalic/ElenaWebRegularItalic-subset-v2.woff2www.smashingmagazine.com/fonts/Elen... https://www.smashingmagazine.com/fonts/ElenaWebRegularItalic/ElenaWebRegularItalic-subset-v2.woff2 — 200 — 17.1 KiB — 22 ms — h2https://www.smashingmagazine.com/images/logo.svgwww.smashingmagazine.com/images/log... https://www.smashingmagazine.com/images/logo.svg — 200 — 1.1 KiB — 25 ms — h2data:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAADybWV0YQAAAAAAAAAoaGRscgAAAAAA…data:image/avif;base64,AAAAIGZ0eXBh... data:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAADybWV0YQAAAAAAAAAoaGRscgAAAAAA… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAAGhbWV0YQAAAAAAAAAoaGRscgAAAAAA…data:image/avif;base64,AAAAIGZ0eXBh... data:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAAGhbWV0YQAAAAAAAAAoaGRscgAAAAAA… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAGGZ0eXBhdmlmAAAAAGF2aWZtaWYxAAAA2W1ldGEAAAAAAAAAIWhkbHIAAAAAAAAAAHBpY3QA…data:image/avif;base64,AAAAGGZ0eXBh... data:image/avif;base64,AAAAGGZ0eXBhdmlmAAAAAGF2aWZtaWYxAAAA2W1ldGEAAAAAAAAAIWhkbHIAAAAAAAAAAHBpY3QA… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAO5tZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAO5tZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datahttps://files.smashing.media/person-of-the-week/yiying-lu-250px.aviffiles.smashing.media/person-of-the-... https://files.smashing.media/person-of-the-week/yiying-lu-250px.avif — 200 — 4.7 KiB — 225 ms — h2https://files.smashing.media/community-links/juergen-zimmermann-100px-opt.pngfiles.smashing.media/community-link... https://files.smashing.media/community-links/juergen-zimmermann-100px-opt.png — 200 — 7.8 KiB — 214 ms — h2https://files.smashing.media/community-links/ian-lloyd-100px-opt.pngfiles.smashing.media/community-link... https://files.smashing.media/community-links/ian-lloyd-100px-opt.png — 200 — 7.3 KiB — 216 ms — h2https://files.smashing.media/community-links/taras-bakusevych-opt.pngfiles.smashing.media/community-link... https://files.smashing.media/community-links/taras-bakusevych-opt.png — 200 — 6.8 KiB — 197 ms — h2https://files.smashing.media/community-links/stephanie-walter-100px-opt.pngfiles.smashing.media/community-link... https://files.smashing.media/community-links/stephanie-walter-100px-opt.png — 200 — 8.3 KiB — 199 ms — h2https://files.smashing.media/community-links/tey-bannerman-100px-opt.pngfiles.smashing.media/community-link... https://files.smashing.media/community-links/tey-bannerman-100px-opt.png — 200 — 7.9 KiB — 201 ms — h2https://files.smashing.media/community-links/steve-frenzel-100px-opt.pngfiles.smashing.media/community-link... https://files.smashing.media/community-links/steve-frenzel-100px-opt.png — 200 — 9.0 KiB — 207 ms — h2https://www.smashingmagazine.com/images/smashing-cat/cat-in-the-chair.svgwww.smashingmagazine.com/images/sma... https://www.smashingmagazine.com/images/smashing-cat/cat-in-the-chair.svg — 200 — 7.9 KiB — 21 ms — h2https://www.smashingmagazine.com/css/main.csswww.smashingmagazine.com/css/main.c... https://www.smashingmagazine.com/css/main.css — 200 — 67.8 KiB — 168 ms — h2https://www.smashingmagazine.com/manifest.jsonwww.smashingmagazine.com/manifest.j... https://www.smashingmagazine.com/manifest.json — 200 — 367 B — 199 ms — h2https://www.smashingmagazine.com/css/print.csswww.smashingmagazine.com/css/print.... https://www.smashingmagazine.com/css/print.css — 200 — 4.3 KiB — 151 ms — h2https://www.googletagmanager.com/gtag/js?id=G-CXX395KXNGwww.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-CXX395KXNG — 200 — 150.0 KiB — 35 ms — h2https://www.smashingmagazine.com/.netlify/scripts/rumwww.smashingmagazine.com/.netlify/s... https://www.smashingmagazine.com/.netlify/scripts/rum — 200 — 4.2 KiB — 12 ms — h2
0 ms 500 ms 1.0 s FCP 780 ms LCP 1.1 shttps://smashingmagazine.com// https://smashingmagazine.com/ — 301 — 168 B — 35 ms — h2https://www.smashingmagazine.com/www.smashingmagazine.com/ https://www.smashingmagazine.com/ — 200 — 75.2 KiB — 40 ms — h2https://www.smashingmagazine.com/js/nav-v2.jswww.smashingmagazine.com/js/nav-v2.... https://www.smashingmagazine.com/js/nav-v2.js — 200 — 828 B — 15 ms — h2https://www.smashingmagazine.com/fonts/ElenaWebRegular/ElenaWebRegular-subset-v2.woff2www.smashingmagazine.com/fonts/Elen... https://www.smashingmagazine.com/fonts/ElenaWebRegular/ElenaWebRegular-subset-v2.woff2 — 200 — 16.6 KiB — 31 ms — h2https://www.smashingmagazine.com/fonts/ElenaWebBold/ElenaWebBold-subset-v2.woff2www.smashingmagazine.com/fonts/Elen... https://www.smashingmagazine.com/fonts/ElenaWebBold/ElenaWebBold-subset-v2.woff2 — 200 — 16.9 KiB — 36 ms — h2https://www.smashingmagazine.com/fonts/MijaBold/Mija_Bold-webfont-subset-v2.woff2www.smashingmagazine.com/fonts/Mija... https://www.smashingmagazine.com/fonts/MijaBold/Mija_Bold-webfont-subset-v2.woff2 — 200 — 14.2 KiB — 38 ms — h2https://www.smashingmagazine.com/fonts/ElenaWebRegularItalic/ElenaWebRegularItalic-subset-v2.woff2www.smashingmagazine.com/fonts/Elen... https://www.smashingmagazine.com/fonts/ElenaWebRegularItalic/ElenaWebRegularItalic-subset-v2.woff2 — 200 — 17.1 KiB — 22 ms — h2https://www.smashingmagazine.com/images/logo.svgwww.smashingmagazine.com/images/log... https://www.smashingmagazine.com/images/logo.svg — 200 — 1.1 KiB — 25 ms — h2data:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAADybWV0YQAAAAAAAAAoaGRscgAAAAAA…data:image/avif;base64,AAAAIGZ0eXBh... data:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAADybWV0YQAAAAAAAAAoaGRscgAAAAAA… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAAGhbWV0YQAAAAAAAAAoaGRscgAAAAAA…data:image/avif;base64,AAAAIGZ0eXBh... data:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAAGhbWV0YQAAAAAAAAAoaGRscgAAAAAA… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAGGZ0eXBhdmlmAAAAAGF2aWZtaWYxAAAA2W1ldGEAAAAAAAAAIWhkbHIAAAAAAAAAAHBpY3QA…data:image/avif;base64,AAAAGGZ0eXBh... data:image/avif;base64,AAAAGGZ0eXBhdmlmAAAAAGF2aWZtaWYxAAAA2W1ldGEAAAAAAAAAIWhkbHIAAAAAAAAAAHBpY3QA… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAO5tZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAO5tZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... data:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw… — 200 — 0 B — 0 ms — datadata:image/avif;base64,AAAAHGZ0eXBtaWYxAAAAAG1pZjFhdmlmbWlhZgAAAPNtZXRhAAAAAAAAACFoZGxyAAAAAAAAAABw…data:image/avif;base64,AAAAHGZ0eXBt... 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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 649ms · 225KB · €7/mo
www.smashingmagazine.com
Other
Costly
Execution 472ms
Transfer 75 KB
Monthly Cost €5/mo
Unattributable
Other
Optional
Execution 104ms
Transfer 0 KB
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 73ms
Transfer 150 KB
Unused 56%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • www.smashingmagazine.com adds 472ms and costs ~€5/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.smashingmagazine.com takes 472ms 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

56% of Google Tag Manager'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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