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https://simonandschuster.com

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
76
GRADE
C
FIX
5
REVIEW
3
PASS
7
INFO
2

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

Mobile Desktop
60
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
70
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
77
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.

2.81 s

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

15.89 s

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

351 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.

4.45 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.

15.89 s

Page Load Progression

463 ms
926 ms
1.4 s
1.9 s
2.3 s
2.8 s
3.2 s
3.7 s
Checks
17
7 PASS 3 REVIEW 5 FIX
F
Page Weight Budget
Action
2.6 MB transferred, 27 requests
FIX
2.6 MB transferred, 27 requests
Warning::
Page weighs 3.9 MB (2.6 MB transferred)
Info::
27 HTTP requests
Info::
Estimated 0.56 g CO2 per page load
2.6 MB / 2.4 MB budget
2.6 MB transferred
27 requests
0.56 g CO2 per page load
Other 1.9 MiB 71%
JavaScript 382.6 KiB 14%
Images 242.9 KiB 9%
Fonts 85.0 KiB 3%
HTML 36.1 KiB 1%
CSS 32.2 KiB 1%
Other 3.0 KiB 0%
Other 819 B 0%
Other 757 B 0%
0 2.4 MB 4.9 MB
Over budget
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 (2.6 MiB of 2.6 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
JS Execution Cost
Action
2194ms total JS execution
FIX
2194ms total JS execution
Warning::
https://www.simonandschuster.com/: 470ms CPU time
Warning::
https://d1dyndsnc54cq8.cloudfront.net/assets/promo...: 382ms CPU time
Warning::
https://d1dyndsnc54cq8.cloudfront.net/assets/appli...: 335ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-P2L...: 306ms CPU time
Warning::
Unattributable: 285ms CPU time
Warning::
Third-party scripts: 2194ms (100% of total)

Main Thread Breakdown

Script Evaluation 46% Other 23% Style & Layout 16% Rendering 5% Script Parsing & Compilation 5%
ScriptTotalScriptingParse/CompileParty
https://www.simonandschuster.com/470ms96ms4ms3rd
https://d1dyndsnc54cq8.cloudfront.net/assets/promo_ticker_d0be803b75f281fadc72.js382ms107ms7ms3rd
https://d1dyndsnc54cq8.cloudfront.net/assets/application_adbe318fb7b4a6039ab7.js335ms220ms24ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-P2LJ2NV306ms250ms47ms3rd
Unattributable285ms8ms0ms3rd
https://www.simonandschuster.com/cdn-cgi/challenge-platform/scripts/jsd/main.js230ms205ms2ms3rd
https://sdks.shopifycdn.com/buy-button/latest/buy-button-storefront.min.js185ms137ms30ms3rd
D
Page Weight Inventory
Action
27 resources · 2.6 MB · 161 KB savings available
FIX
27 resources · 2.6 MB · 161 KB savings available
Warning::
Page weight 1.6 MB over 1MB target
Got: 2.6 MB Expected: ≤ 1 MB
Info::
~161 KB of savings available
Warning::
26 third-party resources (100% of weight)
Info::
1 resources over 200KB
27 resources · 2.6 MiB · 26 third-party 1.6 MiB over 1MB target
Media 71% · 1.9 MiB
JavaScript 14% · 382.6 KiB
Image 9% · 245.5 KiB
Font 3% · 85.0 KiB
Document 1% · 36.3 KiB
CSS 1% · 32.2 KiB
Other 0% · 1.7 KiB

~161.1 KiB of savings available

Remove unused JavaScript: 161.1 KiB
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
7 images, 0 KB saveable
REVIEW
7 images, 0 KB saveable
Warning::
https://d28hgpri8am2if.cloudfront.net/book_images/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://d28hgpri8am2if.cloudfront.net/book_images/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://d28hgpri8am2if.cloudfront.net/book_images/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://d1hbl61hovme3a.cloudfront.net/assets_us/mo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://d28hgpri8am2if.cloudfront.net/book_images/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
7 images 243 KB
0 oversized -0 KB
6 legacy format
6 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

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

Performance issues directly impact user engagement and conversion rates.

C
JS Bundles
Action
7 scripts, 161 KB unused
REVIEW
7 scripts, 161 KB unused
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-P2L...: 79 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://d1dyndsnc54cq8.cloudfront.net/assets/appli...: 50 KB unused (51%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://sdks.shopifycdn.com/buy-button/latest/buy-...: 32 KB unused (54%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 161 KB
161 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtm.js?id=GTM-P2LJ2NV178 KB79 KB (44%)✓3rd
https://d1dyndsnc54cq8.cloudfront.net/assets/application_adbe318fb7b4a6039ab7.js100 KB50 KB (51%)✓3rd
https://sdks.shopifycdn.com/buy-button/latest/buy-button-storefront.min.js60 KB32 KB (54%)✓3rd
https://d1dyndsnc54cq8.cloudfront.net/assets/promo_ticker_d0be803b75f281fadc72.js28 KB—✓3rd
https://d1dyndsnc54cq8.cloudfront.net/assets/bulma_billboard_c4af258eeef61cf39ac6.js4 KB—✓3rd
https://www.simonandschuster.com/cdn-cgi/challenge-platform/h/b/scripts/jsd/0b8fb825cb67/main.js?13 KB—✓3rd
https://cdn.cookielaw.org/scripttemplates/otSDKStub.js0 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

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
5 fonts (85 KB)
PASS
5 fonts (85 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

85 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 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 2.8 s LCP 15.9 sdata:application/font-woff;charset=utf-8;base64, d09GRgABAAAAAAZgABAAAAAADAAAAAAAAAAAAAAAAAAAAAAAAA…font-woff;charset=utf-8... data:application/font-woff;charset=utf-8;base64, d09GRgABAAAAAAZgABAAAAAADAAAAAAAAAAAAAAAAAAAAAAAAA… — 1.6 KiB — 47 ms — font-display: swaphttps://d1dyndsnc54cq8.cloudfront.net/assets/Hind-Regular_b2d495f1d7e95c8e120c05fc490ef3f1.woff2Hind-Regular_b2d495f1d7... https://d1dyndsnc54cq8.cloudfront.net/assets/Hind-Regular_b2d495f1d7e95c8e120c05fc490ef3f1.woff2 — 17.7 KiB — 57 ms — font-display: swaphttps://d1dyndsnc54cq8.cloudfront.net/assets/LibreBaskerville-Regular_adb196b250bef55fb52c38d1a7226c14.woff2LibreBaskerville-Regula... https://d1dyndsnc54cq8.cloudfront.net/assets/LibreBaskerville-Regular_adb196b250bef55fb52c38d1a7226c14.woff2 — 29.6 KiB — 76 ms — font-display: swaphttps://d1dyndsnc54cq8.cloudfront.net/assets/Hind-SemiBold_9d94ebbc848672930d789dcb27fd7b7d.woff2Hind-SemiBold_9d94ebbc8... https://d1dyndsnc54cq8.cloudfront.net/assets/Hind-SemiBold_9d94ebbc848672930d789dcb27fd7b7d.woff2 — 18.5 KiB — 69 ms — font-display: swaphttps://d1dyndsnc54cq8.cloudfront.net/assets/Hind-Bold_5d3067799d22ffbc9ef8343bdbd1ce47.woff2Hind-Bold_5d3067799d22f... https://d1dyndsnc54cq8.cloudfront.net/assets/Hind-Bold_5d3067799d22ffbc9ef8343bdbd1ce47.woff2 — 17.6 KiB — 71 ms — font-display: swap
font-woff;charset=utf-8... woff swap
Size 2 KB
Load time 47 ms
Start 949 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
Hind-Regular_b2d495f1d7... woff2 swap
Size 18 KB
Load time 57 ms
Start 993 ms
Risk FOUT — text flashes from fallback to web font
LibreBaskerville-Regula... woff2 swap
Size 30 KB
Load time 76 ms
Start 993 ms
Risk FOUT — text flashes from fallback to web font
Hind-SemiBold_9d94ebbc8... woff2 swap
Size 19 KB
Load time 69 ms
Start 993 ms
Risk FOUT — text flashes from fallback to web font
Hind-Bold_5d3067799d22f... woff2 swap
Size 18 KB
Load time 71 ms
Start 994 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
3 hints, 0 missing preconnects
PASS
3 hints, 0 missing preconnects
Info::
Page uses 3 resource hint(s)

Current Resource Hints

preconnect
—
preload
—
dns-prefetch
3
prefetch
—

3 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
Network Waterfall
27 requests over 1503ms
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 2.8 s LCP 15.9 shttps://simonandschuster.com// https://simonandschuster.com/ — 301 — 297 B — 301 ms — h2https://www.simonandschuster.com/www.simonandschuster.com/ https://www.simonandschuster.com/ — 200 — 36.1 KiB — 505 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/application_639907eb8e5e4e5f9814.cssd1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/application_639907eb8e5e4e5f9814.css — 200 — 31.0 KiB — 104 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/promo_ticker_6b2447ddbbd5639cf418.cssd1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/promo_ticker_6b2447ddbbd5639cf418.css — 200 — 1.2 KiB — 100 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/application_adbe318fb7b4a6039ab7.jsd1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/application_adbe318fb7b4a6039ab7.js — 200 — 99.6 KiB — 38 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/promo_ticker_d0be803b75f281fadc72.jsd1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/promo_ticker_d0be803b75f281fadc72.js — 200 — 28.0 KiB — 39 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/bulma_billboard_c4af258eeef61cf39ac6.jsd1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/bulma_billboard_c4af258eeef61cf39ac6.js — 200 — 4.1 KiB — 37 ms — h2https://www.googletagmanager.com/gtm.js?id=GTM-P2LJ2NVwww.googletagmanager.com/gtm.js?id=... https://www.googletagmanager.com/gtm.js?id=GTM-P2LJ2NV — 200 — 178.0 KiB — 169 ms — h2https://sdks.shopifycdn.com/buy-button/latest/buy-button-storefront.min.jssdks.shopifycdn.com/buy-button/late... https://sdks.shopifycdn.com/buy-button/latest/buy-button-storefront.min.js — 200 — 60.3 KiB — 126 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/540a7631d3f89742b767e53536e7ebc7.jpgd1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/540a7631d3f89742b767e53536e7ebc7.jpg — 200 — 26.4 KiB — 22 ms — h2data:application/font-woff;charset=utf-8;base64, d09GRgABAAAAAAZgABAAAAAADAAAAAAAAAAAAAAAAAAAAAAAAA…data:application/font-woff;charset=... data:application/font-woff;charset=utf-8;base64, d09GRgABAAAAAAZgABAAAAAADAAAAAAAAAAAAAAAAAAAAAAAAA… — 200 — 1.6 KiB — 47 ms — datahttps://d1dyndsnc54cq8.cloudfront.net/assets/Hind-Regular_b2d495f1d7e95c8e120c05fc490ef3f1.woff2d1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/Hind-Regular_b2d495f1d7e95c8e120c05fc490ef3f1.woff2 — 200 — 17.7 KiB — 57 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/LibreBaskerville-Regular_adb196b250bef55fb52c38d1a7226c14.woff2d1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/LibreBaskerville-Regular_adb196b250bef55fb52c38d1a7226c14.woff2 — 200 — 29.6 KiB — 76 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/Hind-SemiBold_9d94ebbc848672930d789dcb27fd7b7d.woff2d1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/Hind-SemiBold_9d94ebbc848672930d789dcb27fd7b7d.woff2 — 200 — 18.5 KiB — 69 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/Hind-Bold_5d3067799d22ffbc9ef8343bdbd1ce47.woff2d1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/Hind-Bold_5d3067799d22ffbc9ef8343bdbd1ce47.woff2 — 200 — 17.6 KiB — 71 ms — h2https://d1hbl61hovme3a.cloudfront.net/assets_us/110466-caretaker-sns-billboard.mp4d1hbl61hovme3a.cloudfront.net/asset... https://d1hbl61hovme3a.cloudfront.net/assets_us/110466-caretaker-sns-billboard.mp4 — 206 — 1.9 MiB — 155 ms — h2https://www.simonandschuster.com/cdn-cgi/challenge-platform/scripts/jsd/main.jswww.simonandschuster.com/cdn-cgi/ch... https://www.simonandschuster.com/cdn-cgi/challenge-platform/scripts/jsd/main.js — 302 — 164 B — 96 ms — h2https://monorail-edge.shopifysvc.com/v1/producemonorail-edge.shopifysvc.com/v1/pro... https://monorail-edge.shopifysvc.com/v1/produce — 200 — 819 B — 220 ms — h2https://www.simonandschuster.com/cdn-cgi/challenge-platform/h/b/scripts/jsd/0b8fb825cb67/main.js?www.simonandschuster.com/cdn-cgi/ch... https://www.simonandschuster.com/cdn-cgi/challenge-platform/h/b/scripts/jsd/0b8fb825cb67/main.js? — 200 — 12.5 KiB — 24 ms — h2https://cdn.cookielaw.org/scripttemplates/otSDKStub.jscdn.cookielaw.org/scripttemplates/o... https://cdn.cookielaw.org/scripttemplates/otSDKStub.js — -1 — 0 B — 100 ms — https://www.simonandschuster.com/cdn-cgi/challenge-platform/h/b/jsd/oneshot/0b8fb825cb67/0.6688030970413026:1776809557:O7rLN3nqnRpqq1ETlvF4OHvbb1xtfdyTnSr74k0fOwE/9effd8d26cc6f180www.simonandschuster.com/cdn-cgi/ch... https://www.simonandschuster.com/cdn-cgi/challenge-platform/h/b/jsd/oneshot/0b8fb825cb67/0.6688030970413026:1776809557:O7rLN3nqnRpqq1ETlvF4OHvbb1xtfdyTnSr74k0fOwE/9effd8d26cc6f180 — 200 — 757 B — 40 ms — h2https://d28hgpri8am2if.cloudfront.net/book_images/onix/cvr9781668033104/this-land-is-your-land-9781668033104.jpgd28hgpri8am2if.cloudfront.net/book_... https://d28hgpri8am2if.cloudfront.net/book_images/onix/cvr9781668033104/this-land-is-your-land-9781668033104.jpg — 200 — 19.5 KiB — 58 ms — h2https://d28hgpri8am2if.cloudfront.net/book_images/onix/cvr9781668236512/theo-of-golden-9781668236512.jpgd28hgpri8am2if.cloudfront.net/book_... https://d28hgpri8am2if.cloudfront.net/book_images/onix/cvr9781668236512/theo-of-golden-9781668236512.jpg — 200 — 11.4 KiB — 58 ms — h2https://d28hgpri8am2if.cloudfront.net/book_images/onix/cvr9781982134594/apple-9781982134594.jpgd28hgpri8am2if.cloudfront.net/book_... https://d28hgpri8am2if.cloudfront.net/book_images/onix/cvr9781982134594/apple-9781982134594.jpg — 200 — 6.9 KiB — 67 ms — h2https://d1hbl61hovme3a.cloudfront.net/assets_us/mother%27s-day-tentpoles-content-card.pngd1hbl61hovme3a.cloudfront.net/asset... https://d1hbl61hovme3a.cloudfront.net/assets_us/mother%27s-day-tentpoles-content-card.png — 200 — 166.3 KiB — 26 ms — h2https://d1dyndsnc54cq8.cloudfront.net/assets/favicon-global.pngd1dyndsnc54cq8.cloudfront.net/asset... https://d1dyndsnc54cq8.cloudfront.net/assets/favicon-global.png — 200 — 2.5 KiB — 19 ms — h2https://d28hgpri8am2if.cloudfront.net/book_images/onix/cvr9781668068809/rory-9781668068809.jpgd28hgpri8am2if.cloudfront.net/book_... https://d28hgpri8am2if.cloudfront.net/book_images/onix/cvr9781668068809/rory-9781668068809.jpg — 200 — 12.4 KiB — 19 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 2194ms · 402KB · €12/mo
www.simonandschuster.com
Other
Costly
Execution 470ms
Transfer 36 KB
Monthly Cost €2/mo
d1dyndsnc54cq8.cloudfront.net
Other
Costly
Execution 382ms
Transfer 28 KB
Monthly Cost €2/mo
d1dyndsnc54cq8.cloudfront.net
Other
Costly
Execution 335ms
Transfer 100 KB
Unused 51%
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Costly
Execution 306ms
Transfer 178 KB
Unused 44%
Monthly Cost €2/mo
Unattributable
Other
Costly
Execution 285ms
Transfer 0 KB
Monthly Cost €2/mo
www.simonandschuster.com
Other
Costly
Execution 230ms
Transfer 0 KB
Monthly Cost €1/mo
sdks.shopifycdn.com
Other
Optional
Execution 185ms
Transfer 60 KB
Unused 54%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • www.simonandschuster.com adds 470ms and costs ~€2/month
  • d1dyndsnc54cq8.cloudfront.net adds 382ms and costs ~€2/month
  • d1dyndsnc54cq8.cloudfront.net adds 335ms and costs ~€2/month
  • Google Tag Manager adds 306ms and costs ~€2/month
  • Unattributable adds 285ms and costs ~€2/month
  • www.simonandschuster.com adds 230ms and costs ~€1/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.simonandschuster.com takes 470ms 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

d1dyndsnc54cq8.cloudfront.net takes 382ms 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

d1dyndsnc54cq8.cloudfront.net takes 335ms 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

51% of d1dyndsnc54cq8.cloudfront.net'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

Google Tag Manager takes 306ms 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 285ms 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.simonandschuster.com takes 230ms 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

54% of sdks.shopifycdn.com'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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