Performance
· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
2.70 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
4.15 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
6.79 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.002
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
14.41 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.
30.07 s
Page Load Progression
1.2 s
2.4 s
3.6 s
4.8 s
5.9 s
7.1 s
8.3 s
9.5 sFPage Weight BudgetAction5.6 MB transferred, 321 requestsFIX
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
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.
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction18958ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.sonos.com/_next/static/chunks/3528-22399f527ed2dbbd.js?dpl=dpl_HR77npGmmWfDQznR71rQzE97oiSB | 4911ms | 4299ms | 28ms | 3rd |
| Unattributable | 1659ms | 189ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WRJKFWM | 1327ms | 1068ms | 111ms | 3rd |
| https://www.sonos.com/_next/static/chunks/61b5e853-8430af891c2cc329.js?dpl=dpl_HR77npGmmWfDQznR71rQzE97oiSB | 1223ms | 828ms | 25ms | 3rd |
| https://www.sonos.com/s3t4F/Mql/2NIV/Ba/uiwMzO/DOL3tmf6kGNhkzE1/QEQ-AQ/RlQ4d/xxzSxQB | 1037ms | 944ms | 72ms | 3rd |
| https://www.sonos.com/en/home | 1031ms | 28ms | 100ms | 3rd |
| https://forms.sonos.com/w37htfhcq2/vendor/b438b2ba-e8de-42c1-938e-5fc1ebffe53b/main.js?cb=8DCB3ECB413095BC01D1B29BF4757228 | 787ms | 449ms | 57ms | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=DC-13670001&cx=c>m=4e64k1 | 765ms | 696ms | 48ms | 3rd |
| https://forms.sonos.com/w37htfhcq2/vendor/b438b2ba-e8de-42c1-938e-5fc1ebffe53b/custom_box.js?cb=8CB4E6AB033008129410B9D3E1038ADA | 716ms | 568ms | 48ms | 3rd |
| https://assets.sonos.com/optimizelyjs/3058550533.js | 637ms | 560ms | 67ms | 3rd |
Showing top 10 of 32 scripts
FJS BundlesAction104 scripts, 1014 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://t.contentsquare.net/uxa/0ad82fc9-ef51-4833-83db-2e9207f7b731.js | 141 KB | 103 KB (73%) | ✓ | 3rd |
| https://t.contentsquare.net/uxa/0ad82fc9-ef51-4833-83db-2e9207f7b731.js | 0 KB | 103 KB (73%) | ✓ | 3rd |
| https://analytics.sonos.com/p.js | 120 KB | 83 KB (69%) | ✗ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202505.2.0/otBannerSdk.js | 119 KB | 67 KB (56%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=DC-13670001&cx=c>m=4e64k1 | 131 KB | 62 KB (47%) | ✓ | 3rd |
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwOQ.js | 121 KB | 61 KB (51%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-DFV9V8HH8T&cx=c>m=4e64k1 | 176 KB | 58 KB (33%) | ✓ | 3rd |
| https://forms.sonos.com/w37htfhcq2/vendor/b438b2ba-e8de-42c1-938e-5fc1ebffe53b/main.js?cb=8DCB3ECB413095BC01D1B29BF4757228 | 116 KB | 57 KB (49%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=DC-4273294&cx=c>m=4e64k1 | 129 KB | 56 KB (44%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WRJKFWM | 201 KB | 52 KB (26%) | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
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.
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.
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.
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.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
FPage Weight InventoryAction321 resources · 5.6 MB · 1014 KB savings availableFIX
~1013.9 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 321 resources | 5.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization107 images, 0 KB saveableREVIEW
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font Loading1 fonts (37 KB)PASS
Web fonts
1
37 KB total
Render-blocking
0
of 1
Dominant font-display
swap
Most common across fonts
Font loading timeline
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 CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall321 requests over 8721msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.sonos.com www.sonos.com | Other | 4911ms | 51 KB | 46% | $92/mo | Costly |
Unattributable Unattributable | Other | 1659ms | 0 KB | — | $31/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 1327ms | 201 KB | 26% | $25/mo | Costly |
www.sonos.com www.sonos.com | Other | 1223ms | 62 KB | 33% | $23/mo | Costly |
www.sonos.com www.sonos.com | Other | 1037ms | 1 KB | 21% | $19/mo | Costly |
www.sonos.com www.sonos.com | Other | 1031ms | 118 KB | — | $19/mo | Costly |
forms.sonos.com forms.sonos.com | Other | 787ms | 116 KB | 49% | $15/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 765ms | 131 KB | 47% | $14/mo | Costly |
forms.sonos.com forms.sonos.com | Other | 716ms | 0 KB | 43% | $13/mo | Costly |
assets.sonos.com assets.sonos.com | Other | 637ms | 110 KB | 31% | $12/mo | Costly |
t.contentsquare.net t.contentsquare.net | Other | 570ms | 0 KB | 73% | $11/mo | Costly |
analytics.tiktok.com analytics.tiktok.com | Other | 451ms | 121 KB | 51% | $8/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 396ms | 176 KB | 33% | $7/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 360ms | 119 KB | 56% | $7/mo | Essential |
www.sonos.com www.sonos.com | Other | 354ms | 32 KB | — | $7/mo | Costly |
sc-static.net sc-static.net | Other | 319ms | 25 KB | — | $6/mo | Costly |
www.sonos.com www.sonos.com | Other | 293ms | 49 KB | — | $6/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 223ms | 129 KB | 44% | $4/mo | Costly |
www.sonos.com www.sonos.com | Other | 199ms | 33 KB | — | $4/mo | Optional |
www.sonos.com www.sonos.com | Other | 186ms | 29 KB | — | $3/mo | Optional |
s.pinimg.com s.pinimg.com | Other | 180ms | 28 KB | — | $3/mo | Optional |
js.appboycdn.com js.appboycdn.com | Other | 175ms | 63 KB | 53% | $3/mo | Optional |
analytics.sonos.com analytics.sonos.com | Other | 174ms | 120 KB | 69% | $3/mo | Optional |
www.sonos.com www.sonos.com | Other | 150ms | 19 KB | — | $3/mo | Optional |
forms.sonos.com forms.sonos.com | Other | 150ms | 0 KB | 63% | $3/mo | Optional |
scripts.postie.com scripts.postie.com | Other | 150ms | 28 KB | — | $3/mo | Optional |
forms.sonos.com forms.sonos.com | Other | 135ms | 6 KB | — | $3/mo | Optional |
www.sonos.com www.sonos.com | Other | 105ms | 8 KB | — | $2/mo | Optional |
www.sonos.com www.sonos.com | Other | 88ms | 9 KB | — | $2/mo | Optional |
assets.xgen.dev assets.xgen.dev | Other | 74ms | 20 KB | — | $1/mo | Optional |
pixel.byspotify.com pixel.byspotify.com | Other | 67ms | 10 KB | — | $1/mo | Optional |
analytics.tiktok.com analytics.tiktok.com | Other | 65ms | 40 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.sonos.com adds 4911ms and costs ~$92/month
- Unattributable adds 1659ms and costs ~$31/month
- Google Tag Manager adds 1327ms and costs ~$25/month
- www.sonos.com adds 1223ms and costs ~$23/month
- www.sonos.com adds 1037ms and costs ~$19/month
- www.sonos.com adds 1031ms and costs ~$19/month
- forms.sonos.com adds 787ms and costs ~$15/month
- Google Tag Manager adds 765ms and costs ~$14/month
- forms.sonos.com adds 716ms and costs ~$13/month
- assets.sonos.com adds 637ms and costs ~$12/month
- t.contentsquare.net adds 570ms and costs ~$11/month
- analytics.tiktok.com adds 451ms and costs ~$8/month
- Google Tag Manager adds 396ms and costs ~$7/month
- www.sonos.com adds 354ms and costs ~$7/month
- sc-static.net adds 319ms and costs ~$6/month
- www.sonos.com adds 293ms and costs ~$6/month
- Google Tag Manager adds 223ms and costs ~$4/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
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.sonos.com takes 4911ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Unattributable takes 1659ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Google Tag Manager takes 1327ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.sonos.com takes 1223ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.sonos.com takes 1037ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.sonos.com takes 1031ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
forms.sonos.com takes 787ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Google Tag Manager takes 765ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
forms.sonos.com takes 716ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
assets.sonos.com takes 637ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
t.contentsquare.net takes 570ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
73% of t.contentsquare.net's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
analytics.tiktok.com takes 451ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
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.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
Google Tag Manager takes 396ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
56% of OneTrust's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
www.sonos.com takes 354ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
sc-static.net takes 319ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.sonos.com takes 293ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Google Tag Manager takes 223ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
53% of js.appboycdn.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
69% of analytics.sonos.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
63% of forms.sonos.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev