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https://brooklinen.com

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
72
GRADE
C
FIX
5
REVIEW
1
PASS
8
INFO
2

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

18
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
89
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
81
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.

10.69 s

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

24.97 s

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

7.33 s

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

0.165

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

24.09 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.

55.87 s

Page Load Progression

1.9 s
3.9 s
5.8 s
7.7 s
9.7 s
11.6 s
13.5 s
15.4 s
Checks
16
8 PASS 1 REVIEW 5 FIX
F
Page Weight Budget
Action
26.4 MB transferred, 722 requests
FIX
26.4 MB transferred, 722 requests
Critical::
Page weighs 40.2 MB (26.4 MB transferred)
Warning::
JavaScript is 3.9 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 3.9 MB
Warning::
Images are 1.8 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.8 MB
Info::
Fonts are 258 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 258 KB
Warning::
722 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 5.5 g CO2 per page load
26.4 MB / 2.4 MB budget
26.4 MB transferred
722 requests
5.5 g CO2 per page load
Other 18.1 MiB 69%
JavaScript 3.9 MiB 15%
Images 1.8 MiB 7%
Other 1.0 MiB 4%
HTML 774.9 KiB 3%
Other 293.0 KiB 1%
Fonts 258.4 KiB 1%
CSS 112.8 KiB 0%
Other 30.0 KiB 0%
Other 20.1 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over 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

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

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

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (26.4 MiB of 26.4 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
40300ms total JS execution
FIX
40300ms total JS execution
Warning::
Unattributable: 5806ms CPU time
Warning::
https://www.brooklinen.com/cdn/wpm/b0e8c7c7aw41bd7...: 3789ms CPU time
Warning::
https://t.contentsquare.net/uxa/ea6942bbd7cb0.js: 3479ms CPU time
Warning::
https://www.brooklinen.com/: 2972ms CPU time
Warning::
https://cdn.dynamicyield.com/api/8768435/api_stati...: 2786ms CPU time
Warning::
Third-party scripts: 40300ms (100% of total)

Main Thread Breakdown

Script Evaluation 59% Other 23% Style & Layout 9% Script Parsing & Compilation 4%
ScriptTotalScriptingParse/CompileParty
Unattributable5806ms565ms0ms3rd
https://www.brooklinen.com/cdn/wpm/b0e8c7c7aw41bd75a1p837d7fd4m8b145375m.js3789ms2184ms19ms3rd
https://t.contentsquare.net/uxa/ea6942bbd7cb0.js3479ms3063ms45ms3rd
https://www.brooklinen.com/2972ms531ms350ms3rd
https://cdn.dynamicyield.com/api/8768435/api_static.js2786ms1841ms51ms3rd
https://www.brooklinen.com/cdn/shop/t/4417/assets/ProductModal-166a90f8.js2446ms1648ms2ms3rd
https://www.brooklinen.com/cdn/shop/t/4417/assets/splide.esm-688b6f4b.js2353ms453ms0ms3rd
https://www.brooklinen.com/cdn/shop/t/4417/assets/brooklinen-theme.js?v=1691455954737042889017755931022199ms1322ms1ms3rd
https://rapid-cdn.yottaa.com/rapid/lib/cTNGTFD40YMBwA.js1974ms1690ms21ms3rd
https://cdn.us.heap-api.com/v5/heapjs-static/5.3.10/core/heap.js1088ms990ms28ms3rd

Showing top 10 of 55 scripts

F
JS Bundles
Action
229 scripts, 1.4 MB unused
FIX
229 scripts, 1.4 MB unused
Warning::
https://sdk.postscript.io/sdk.bundle.js?shopId=166...: 145 KB unused (72%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=AW-973...: 102 KB unused (75%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.dynamicyield.com/api/8768435/api_stati...: 91 KB unused (58%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://2b36d2a1092a.cdn4.forter.com/sn/2b36d2a109...: 89 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://accounts.google.com/gsi/client: 67 KB unused (72%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.4 MB
1428 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://sdk.postscript.io/sdk.bundle.js?shopId=1664202 KB145 KB (72%)3rd
https://www.googletagmanager.com/gtag/js?id=AW-973522331&cx=c&gtm=4e6461h1137 KB102 KB (75%)3rd
https://cdn.dynamicyield.com/api/8768435/api_static.js158 KB91 KB (58%)3rd
https://2b36d2a1092a.cdn4.forter.com/sn/2b36d2a1092a/script.js215 KB89 KB (42%)3rd
https://accounts.google.com/gsi/client93 KB67 KB (72%)3rd
https://www.googletagmanager.com/gtag/js?id=G-80JGCF4NMJ&cx=c&gtm=4e6461173 KB64 KB (37%)3rd
https://www.googletagmanager.com/gtag/destination?id=DC-11096279&cx=c&gtm=4e6461130 KB59 KB (46%)3rd
https://t.contentsquare.net/uxa/ea6942bbd7cb0.js132 KB59 KB (45%)3rd
https://www.googletagmanager.com/gtm.js?id=GTM-N3WBV32177 KB58 KB (33%)3rd
https://www.googletagmanager.com/gtag/js?id=AW-930458877143 KB58 KB (40%)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

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
HTTP Caching
Action
no-store (uncacheable)
FIX
no-store (uncacheable)
Info::
Cache-Control: no-store prevents all caching
Intentional for dynamic content, but increases server load for every page view.
Got: private, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

private, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0

DirectiveValueMeaning
privateOnly browser cache, not CDN/proxy
max-age0Cache for 0 seconds
no-storeNever cache this response
no-cacheCache but always revalidate first
must-revalidateMust recheck with server after expiry
post-check0
pre-check0
B
Image Optimization
133 images, 0 KB saveable
REVIEW
133 images, 0 KB saveable
Info::
All images are well-optimized
133 images 1.8 MB
0 oversized -0 KB
24 legacy format
0 missing dimensions CLS risk
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
9 fonts (329 KB)
PASS
9 fonts (329 KB)
Info::
9 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

9

329 KB total

Render-blocking

0

of 9

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 18.0 s 20.0 s 22.0 s 24.0 s 26.0 s FCP 10.7 s LCP 25.0 shttps://www.brooklinen.com/cdn/shop/files/f__BrandonTextRegular.woff2?v=2923255800735255676f__BrandonTextRegular.w... https://www.brooklinen.com/cdn/shop/files/f__BrandonTextRegular.woff2?v=2923255800735255676 — 34.8 KiB — 0 ms — font-display: swaphttps://www.brooklinen.com/cdn/shop/files/wf_BrandonTextWeb-Medium--360967_B_0.woff2?v=18048165408412969505wf_BrandonTextWeb-Mediu... https://www.brooklinen.com/cdn/shop/files/wf_BrandonTextWeb-Medium--360967_B_0.woff2?v=18048165408412969505 — 33.5 KiB — 0 ms — font-display: swaphttps://www.brooklinen.com/cdn/shop/files/f__BrandonTextBold.woff2?v=9945025441678652657f__BrandonTextBold.woff2 https://www.brooklinen.com/cdn/shop/files/f__BrandonTextBold.woff2?v=9945025441678652657 — 35.8 KiB — 0 ms — font-display: swaphttps://www.brooklinen.com/cdn/shop/files/f__BrandonTextWeb-Italic--360967_8_0.woff2?v=13318003604299643776f__BrandonTextWeb-Itali... https://www.brooklinen.com/cdn/shop/files/f__BrandonTextWeb-Italic--360967_8_0.woff2?v=13318003604299643776 — 33.3 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/s/files/1/0951/7126/files/ToledoSerial-Bold.otf?v=1751402923ToledoSerial-Bold.otf https://cdn.shopify.com/s/files/1/0951/7126/files/ToledoSerial-Bold.otf?v=1751402923 — 28.9 KiB — 0 ms — font-display: swaphttps://www.brooklinen.com/cdn/shop/files/ToledoSerial-Bold.otf?v=1751402923ToledoSerial-Bold.otf https://www.brooklinen.com/cdn/shop/files/ToledoSerial-Bold.otf?v=1751402923 — 28.8 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/shop-assets/static_uploads/shoplift/GTStandard-MRegular.woff2GTStandard-MRegular.woff2 https://cdn.shopify.com/shop-assets/static_uploads/shoplift/GTStandard-MRegular.woff2 — 63.2 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/s/files/1/0951/7126/files/f__BrandonTextRegular.woff2?v=1713457452f__BrandonTextRegular.w... https://cdn.shopify.com/s/files/1/0951/7126/files/f__BrandonTextRegular.woff2?v=1713457452 — 34.7 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/s/files/1/0951/7126/files/f__BrandonTextBold.woff2?v=1713457452f__BrandonTextBold.woff2 https://cdn.shopify.com/s/files/1/0951/7126/files/f__BrandonTextBold.woff2?v=1713457452 — 35.6 KiB — 0 ms — font-display: swap
f__BrandonTextRegular.w... woff2 swap
Size 35 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
wf_BrandonTextWeb-Mediu... woff2 swap
Size 34 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
f__BrandonTextBold.woff2 woff2 swap
Size 36 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
f__BrandonTextWeb-Itali... woff2 swap
Size 33 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ToledoSerial-Bold.otf otf swap
Size 29 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
ToledoSerial-Bold.otf otf swap
Size 29 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
GTStandard-MRegular.woff2 woff2 swap
Size 63 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
f__BrandonTextRegular.w... woff2 swap
Size 35 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
f__BrandonTextBold.woff2 woff2 swap
Size 36 KB
Load time 0 ms
Start 0 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)

Fixing the unchecked items could save ~17 KB and ~34 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
29 hints, 0 missing preconnects
PASS
29 hints, 0 missing preconnects
Info::
Page uses 29 resource hint(s)

Current Resource Hints

preconnect
10
preload
5
dns-prefetch
+4
14
prefetch

29 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+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
722 requests over 0ms
INFO

Performance analysis not available for this result.

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 40300ms · 3248KB · €214/mo
Unattributable
Other
Costly
Execution 5806ms
Transfer 0 KB
Monthly Cost €31/mo
www.brooklinen.com
Other
Costly
Execution 3789ms
Transfer 61 KB
Unused 39%
Monthly Cost €20/mo
t.contentsquare.net
Other
Costly
Execution 3479ms
Transfer 132 KB
Unused 45%
Monthly Cost €18/mo
www.brooklinen.com
Other
Costly
Execution 2972ms
Transfer 108 KB
Monthly Cost €16/mo
cdn.dynamicyield.com
Other
Costly
Execution 2786ms
Transfer 158 KB
Unused 58%
Monthly Cost €15/mo
www.brooklinen.com
Other
Costly
Execution 2446ms
Transfer 129 KB
Unused 42%
Monthly Cost €13/mo
www.brooklinen.com
Other
Costly
Execution 2353ms
Transfer 14 KB
Monthly Cost €12/mo
www.brooklinen.com
Other
Costly
Execution 2199ms
Transfer 41 KB
Unused 55%
Monthly Cost €12/mo
rapid-cdn.yottaa.com
Other
Costly
Execution 1974ms
Transfer 45 KB
Unused 61%
Monthly Cost €10/mo
cdn.us.heap-api.com
Other
Costly
Execution 1088ms
Transfer 82 KB
Unused 41%
Monthly Cost €6/mo
st.dynamicyield.com
Other
Costly
Execution 913ms
Transfer 6 KB
Monthly Cost €5/mo
static-resources.botnot.io
Other
Costly
Execution 894ms
Transfer 50 KB
Monthly Cost €5/mo
2b36d2a1092a.cdn4.forter.com
Other
Costly
Execution 852ms
Transfer 215 KB
Unused 42%
Monthly Cost €5/mo
www.redditstatic.com
Other
Costly
Execution 770ms
Transfer 19 KB
Monthly Cost €4/mo
Google Tag Manager
Tag Manager
Costly
Execution 766ms
Transfer 177 KB
Unused 33%
Monthly Cost €4/mo
cdn.shopify.com
Other
Costly
Execution 749ms
Transfer 1 KB
Unused 60%
Monthly Cost €4/mo
Google Tag Manager
Tag Manager
Costly
Execution 558ms
Transfer 143 KB
Unused 40%
Monthly Cost €3/mo
Google Tag Manager
Tag Manager
Costly
Execution 534ms
Transfer 173 KB
Unused 37%
Monthly Cost €3/mo
sdk.postscript.io
Other
Costly
Execution 476ms
Transfer 202 KB
Unused 72%
Monthly Cost €3/mo
www.brooklinen.com
Other
Costly
Execution 349ms
Transfer 31 KB
Monthly Cost €2/mo
d38xvr37kwwhcm.cloudfront.net
Other
Costly
Execution 332ms
Transfer 16 KB
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Costly
Execution 271ms
Transfer 130 KB
Unused 46%
Monthly Cost €1/mo
sc-static.net
Other
Costly
Execution 239ms
Transfer 25 KB
Monthly Cost €1/mo
brooklinen2.myshopify.com
Other
Costly
Execution 233ms
Transfer 1 KB
Monthly Cost €1/mo
www.brooklinen.com
Other
Costly
Execution 222ms
Transfer 28 KB
Monthly Cost €1/mo
analytics.tiktok.com
Other
Costly
Execution 201ms
Transfer 110 KB
Unused 51%
Monthly Cost €1/mo
www.brooklinen.com
Other
Optional
Execution 186ms
Transfer 21 KB
Monthly Cost €1/mo
s.pinimg.com
Other
Optional
Execution 183ms
Transfer 28 KB
Monthly Cost €1/mo
Facebook Pixel
Advertising
Optional
Execution 171ms
Transfer 95 KB
Unused 34%
Monthly Cost €1/mo
cdn.dynamicyield.com
Other
Optional
Execution 158ms
Transfer 65 KB
Monthly Cost €1/mo
www.brooklinen.com
Other
Optional
Execution 156ms
Transfer 4 KB
Monthly Cost €1/mo
(program):2
Other
Optional
Execution 143ms
Transfer 0 KB
Monthly Cost €1/mo
cdn.shopify.com
Other
Optional
Execution 140ms
Transfer 1 KB
Unused 81%
Monthly Cost €1/mo
cdn.gladly.com
Other
Optional
Execution 129ms
Transfer 44 KB
Unused 53%
Monthly Cost €1/mo
b-code.liadm.com
Other
Optional
Execution 122ms
Transfer 45 KB
Monthly Cost €1/mo
js.afterpay.com
Other
Optional
Execution 114ms
Transfer 74 KB
Unused 43%
Monthly Cost €1/mo
px.mountain.com
Other
Optional
Execution 113ms
Transfer 1 KB
Monthly Cost €1/mo
www.brooklinen.com
Other
Optional
Execution 108ms
Transfer 26 KB
Monthly Cost €1/mo
cdn.shopify.com
Other
Optional
Execution 107ms
Transfer 49 KB
Unused 49%
Monthly Cost €1/mo
dx.mountain.com
Other
Optional
Execution 100ms
Transfer 7 KB
Monthly Cost €1/mo
gs.mountain.com
Other
Optional
Execution 96ms
Transfer 0 KB
Monthly Cost €1/mo
Facebook Pixel
Advertising
Optional
Execution 95ms
Transfer 37 KB
Monthly Cost €1/mo
www.brooklinen.com
Other
Optional
Execution 93ms
Transfer 4 KB
Monthly Cost €0/mo
Google Tag Manager
Tag Manager
Optional
Execution 92ms
Transfer 137 KB
Unused 40%
Monthly Cost €0/mo
d.impactradius-event.com
Other
Optional
Execution 85ms
Transfer 20 KB
Monthly Cost €0/mo
www.brooklinen.com
Other
Optional
Execution 83ms
Transfer 23 KB
Monthly Cost €0/mo
cdn.shoppinggives.com
Other
Optional
Execution 80ms
Transfer 73 KB
Unused 56%
Monthly Cost €0/mo
chat.siena.cx
Other
Optional
Execution 78ms
Transfer 20 KB
Monthly Cost €0/mo
accounts.google.com
Other
Optional
Execution 78ms
Transfer 93 KB
Unused 72%
Monthly Cost €0/mo
cdn-widgetsrepository.yotpo.com
Other
Optional
Execution 73ms
Transfer 57 KB
Monthly Cost €0/mo
www.brooklinen.com
Other
Optional
Execution 57ms
Transfer 5 KB
Monthly Cost €0/mo
Google Tag Manager
Tag Manager
Optional
Execution 55ms
Transfer 137 KB
Unused 75%
Monthly Cost €0/mo
cdn.shopify.com
Other
Optional
Execution 52ms
Transfer 12 KB
Monthly Cost €0/mo
j.northbeam.io
Other
Optional
Execution 51ms
Transfer 33 KB
Monthly Cost €0/mo
analytics.tiktok.com
Other
Optional
Execution 50ms
Transfer 40 KB
Monthly Cost €0/mo

These scripts may cost more than they're worth

  • Unattributable adds 5806ms and costs ~€31/month
  • www.brooklinen.com adds 3789ms and costs ~€20/month
  • t.contentsquare.net adds 3479ms and costs ~€18/month
  • www.brooklinen.com adds 2972ms and costs ~€16/month
  • cdn.dynamicyield.com adds 2786ms and costs ~€15/month
  • www.brooklinen.com adds 2446ms and costs ~€13/month
  • www.brooklinen.com adds 2353ms and costs ~€12/month
  • www.brooklinen.com adds 2199ms and costs ~€12/month
  • rapid-cdn.yottaa.com adds 1974ms and costs ~€10/month
  • cdn.us.heap-api.com adds 1088ms and costs ~€6/month
  • st.dynamicyield.com adds 913ms and costs ~€5/month
  • static-resources.botnot.io adds 894ms and costs ~€5/month
  • 2b36d2a1092a.cdn4.forter.com adds 852ms and costs ~€5/month
  • www.redditstatic.com adds 770ms and costs ~€4/month
  • Google Tag Manager adds 766ms and costs ~€4/month
  • cdn.shopify.com adds 749ms and costs ~€4/month
  • Google Tag Manager adds 558ms and costs ~€3/month
  • Google Tag Manager adds 534ms and costs ~€3/month
  • sdk.postscript.io adds 476ms and costs ~€3/month
  • www.brooklinen.com adds 349ms and costs ~€2/month
  • d38xvr37kwwhcm.cloudfront.net adds 332ms and costs ~€2/month
  • Google Tag Manager adds 271ms and costs ~€1/month
  • sc-static.net adds 239ms and costs ~€1/month
  • brooklinen2.myshopify.com adds 233ms and costs ~€1/month
  • www.brooklinen.com adds 222ms and costs ~€1/month
  • analytics.tiktok.com adds 201ms 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

Unattributable takes 5806ms 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.brooklinen.com takes 3789ms 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

t.contentsquare.net takes 3479ms 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.brooklinen.com takes 2972ms 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

cdn.dynamicyield.com takes 2786ms 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

58% of cdn.dynamicyield.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

www.brooklinen.com takes 2446ms 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.brooklinen.com takes 2353ms 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.brooklinen.com takes 2199ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

55% of www.brooklinen.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

rapid-cdn.yottaa.com takes 1974ms 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

61% of rapid-cdn.yottaa.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

cdn.us.heap-api.com takes 1088ms 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

st.dynamicyield.com takes 913ms 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

static-resources.botnot.io takes 894ms 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

2b36d2a1092a.cdn4.forter.com takes 852ms 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.redditstatic.com takes 770ms 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 766ms 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

cdn.shopify.com takes 749ms 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

60% of cdn.shopify.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

Google Tag Manager takes 558ms 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 534ms 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

sdk.postscript.io takes 476ms 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

72% of sdk.postscript.io'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

www.brooklinen.com takes 349ms 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

d38xvr37kwwhcm.cloudfront.net takes 332ms 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 271ms 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

sc-static.net takes 239ms 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

brooklinen2.myshopify.com takes 233ms 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.brooklinen.com takes 222ms 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

analytics.tiktok.com takes 201ms 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 analytics.tiktok.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

81% of cdn.shopify.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

53% of cdn.gladly.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

56% of cdn.shoppinggives.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

72% of accounts.google.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

75% 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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