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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
68
GRADE
D
FIX
6
REVIEW
2
PASS
7
INFO
2

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

Mobile Desktop
41
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
90
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.

3.39 s

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

14.72 s

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

923 ms

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

0.003

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

7.33 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.

15.50 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
7 PASS 2 REVIEW 6 FIX
F
Page Weight Budget
Action
14.1 MB transferred, 93 requests
FIX
14.1 MB transferred, 93 requests
Critical::
Page weighs 19.1 MB (14.1 MB transferred)
Warning::
Images are 12.6 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 12.6 MB
Warning::
JavaScript is 1.3 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.3 MB
Info::
93 HTTP requests
Info::
Estimated 3.0 g CO2 per page load
14.1 MB / 2.4 MB budget
14.1 MB transferred
93 requests
3.0 g CO2 per page load
Images 12.6 MiB 89%
JavaScript 1.3 MiB 9%
CSS 167.6 KiB 1%
Fonts 64.8 KiB 0%
HTML 61.4 KiB 0%
Other 20.4 KiB 0%
Other 1.4 KiB 0%
Other 388 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

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

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

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 (14.1 MiB of 14.1 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
4777ms total JS execution
FIX
4777ms total JS execution
Warning::
https://www.sennheiser.com/_next/static/chunks/0tp...: 2246ms CPU time
Warning::
https://www.sennheiser.com/en-de: 738ms CPU time
Warning::
Unattributable: 613ms CPU time
Warning::
https://cdn.optimizely.com/js/4875027175178240.js: 425ms CPU time
Warning::
https://app.usercentrics.eu/browser-ui/3.99.0/inde...: 399ms CPU time
Warning::
Third-party scripts: 4777ms (100% of total)

Main Thread Breakdown

Script Evaluation 54% Other 18% Style & Layout 17% Script Parsing & Compilation 7% Rendering 3%
ScriptTotalScriptingParse/CompileParty
https://www.sennheiser.com/_next/static/chunks/0tpccgzewb7zp.js2246ms1687ms18ms3rd
https://www.sennheiser.com/en-de738ms22ms33ms3rd
Unattributable613ms115ms0ms3rd
https://cdn.optimizely.com/js/4875027175178240.js425ms391ms27ms3rd
https://app.usercentrics.eu/browser-ui/3.99.0/index.module.js399ms290ms1ms3rd
https://www.sennheiser.com/_next/static/chunks/0xyynutob2tcl.js198ms79ms114ms3rd
https://www.sennheiser.com/_next/static/chunks/0aj.7klu-11f8.js83ms52ms4ms3rd
https://www.sennheiser.com/_next/static/chunks/0o8qu3wlkba46.js77ms8ms22ms3rd
F
JS Bundles
Action
42 scripts, 717 KB unused
FIX
42 scripts, 717 KB unused
Warning::
https://www.sennheiser.com/_next/static/chunks/0xy...: 343 KB unused (95%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.sennheiser.com/_next/static/chunks/0rt...: 129 KB unused (99%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://app.usercentrics.eu/browser-ui/3.99.0/inde...: 53 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.optimizely.com/js/4875027175178240.js: 34 KB unused (45%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.sennheiser.com/_next/static/chunks/0r4...: 34 KB unused (65%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 717 KB
717 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.sennheiser.com/_next/static/chunks/0xyynutob2tcl.js364 KB343 KB (95%)✓3rd
https://www.sennheiser.com/_next/static/chunks/0rt4v1t9arkri.js130 KB129 KB (99%)✓3rd
https://app.usercentrics.eu/browser-ui/3.99.0/index.module.js121 KB53 KB (44%)✓3rd
https://cdn.optimizely.com/js/4875027175178240.js76 KB34 KB (45%)✓3rd
https://www.sennheiser.com/_next/static/chunks/0r4m3wnd5ngs1.js52 KB34 KB (65%)✓3rd
https://www.sennheiser.com/_next/static/chunks/0xxk445_iw963.js36 KB29 KB (81%)✓3rd
https://www.sennheiser.com/_next/static/chunks/16tmcv-qfnfy5.js68 KB26 KB (39%)✓3rd
https://app.usercentrics.eu/browser-ui/3.99.0/VirtualServiceItem-e4cab338.js49 KB26 KB (54%)✓3rd
https://www.sennheiser.com/_next/static/chunks/0tpccgzewb7zp.js69 KB23 KB (33%)✓3rd
https://www.sennheiser.com/_next/static/chunks/02l79wwqbnvm_.js38 KB21 KB (55%)✓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

F
Page Weight Inventory
Action
93 resources · 14.1 MB · 717 KB savings available
FIX
93 resources · 14.1 MB · 717 KB savings available
Warning::
Page weight 13.1 MB over 1MB target
Got: 14.1 MB Expected: ≤ 1 MB
Info::
~717 KB of savings available
Warning::
92 third-party resources (100% of weight)
Info::
7 resources over 200KB
93 resources · 14.1 MiB · 92 third-party 13.1 MiB over 1MB target
Image 89% · 12.6 MiB
JavaScript 9% · 1.3 MiB
CSS 1% · 167.6 KiB
Font 0% · 64.8 KiB
Document 0% · 61.5 KiB
Other 0% · 21.7 KiB

~716.9 KiB of savings available

Remove unused JavaScript: 716.9 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.

B
Image Optimization
13 images, 0 KB saveable
REVIEW
13 images, 0 KB saveable
Info::
All images are well-optimized
13 images 12.6 MB
0 oversized -0 KB
13 legacy format
0 missing dimensions CLS risk
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
2 fonts (65 KB)
PASS
2 fonts (65 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

65 KB total

Render-blocking

0

of 2

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 FCP 3.4 s LCP 14.7 shttps://www.sennheiser.com/_next/static/media/SennheiserNeueMedium-s.0kvapsgk88sh..woff2SennheiserNeueMedium-s.... https://www.sennheiser.com/_next/static/media/SennheiserNeueMedium-s.0kvapsgk88sh..woff2 — 34.5 KiB — 45 ms — font-display: swaphttps://www.sennheiser.com/_next/static/media/SennheiserNeueRegular-s.0cd5jhw_oeehq.woff2SennheiserNeueRegular-s... https://www.sennheiser.com/_next/static/media/SennheiserNeueRegular-s.0cd5jhw_oeehq.woff2 — 30.4 KiB — 43 ms — font-display: swap
SennheiserNeueMedium-s.... woff2 swap
Size 34 KB
Load time 45 ms
Start 461 ms
Risk FOUT — text flashes from fallback to web font
SennheiserNeueRegular-s... woff2 swap
Size 30 KB
Load time 43 ms
Start 461 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
7 hints, 0 missing preconnects
PASS
7 hints, 0 missing preconnects
Info::
Page uses 7 resource hint(s)

Current Resource Hints

preconnect
1
preload
6
dns-prefetch
—
prefetch
—

7 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
93 requests over 1991ms
INFO
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s FCP 3.4 s LCP 14.7 shttps://sennheiser.com// https://sennheiser.com/ — 301 — 121 B — 27 ms — h2https://www.sennheiser.com/www.sennheiser.com/ https://www.sennheiser.com/ — 307 — 829 B — 161 ms — h2https://www.sennheiser.com/en-dewww.sennheiser.com/en-de https://www.sennheiser.com/en-de — 200 — 58.3 KiB — 141 ms — h2https://assets.sennheiser.com/images/assets/HD_480_PRO_Product_Shot_Cutout_Isometric_View_01.png/Zz04ZjQ2YTc2NjExOGIxMWYxYjZiMGRhODFlODBkNGM4OQ==?width=750assets.sennheiser.com/images/assets... https://assets.sennheiser.com/images/assets/HD_480_PRO_Product_Shot_Cutout_Isometric_View_01.png/Zz04ZjQ2YTc2NjExOGIxMWYxYjZiMGRhODFlODBkNGM4OQ==?width=750 — 200 — 185.1 KiB — 250 ms — h2https://assets.sennheiser.com/images/assets/HD-480-PRO_homepage-block.jpeg/Zz0wOTNhMjcyNjNkN2IxMWYxYjk3MDllZjY1MzEwYmQyNA==?width=750assets.sennheiser.com/images/assets... https://assets.sennheiser.com/images/assets/HD-480-PRO_homepage-block.jpeg/Zz0wOTNhMjcyNjNkN2IxMWYxYjk3MDllZjY1MzEwYmQyNA==?width=750 — 200 — 302.5 KiB — 444 ms — h2https://www.sennheiser.com/_next/static/chunks/0udgwp.sjrfrj.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0udgwp.sjrfrj.css — 200 — 6.4 KiB — 79 ms — h3https://www.sennheiser.com/_next/static/chunks/06mlmbd2c.60_.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/06mlmbd2c.60_.css — 200 — 44.7 KiB — 97 ms — h3https://www.sennheiser.com/_next/static/chunks/0hpljjrfw5nnz.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0hpljjrfw5nnz.css — 200 — 9.6 KiB — 93 ms — h3https://www.sennheiser.com/_next/static/chunks/11t7vhu3czf~z.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/11t7vhu3czf~z.css — 200 — 8.9 KiB — 76 ms — h3https://www.sennheiser.com/_next/static/chunks/0pf3-x~ic4ntv.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0pf3-x~ic4ntv.css — 200 — 9.6 KiB — 93 ms — h3https://www.sennheiser.com/_next/static/chunks/0z5dsp7v1stoq.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0z5dsp7v1stoq.css — 200 — 9.8 KiB — 107 ms — h3https://www.sennheiser.com/_next/static/chunks/0urle5c_hwhtf.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0urle5c_hwhtf.css — 200 — 9.7 KiB — 97 ms — h3https://www.sennheiser.com/_next/static/chunks/0lmq82is_v7wf.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0lmq82is_v7wf.css — 200 — 8.5 KiB — 98 ms — h3https://www.sennheiser.com/_next/static/chunks/105o6urs9z491.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/105o6urs9z491.css — 200 — 9.0 KiB — 99 ms — h3https://www.sennheiser.com/_next/static/chunks/0eyptu_vb2gc3.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0eyptu_vb2gc3.css — 200 — 9.3 KiB — 100 ms — h3https://www.sennheiser.com/_next/static/chunks/0oj~fkdmzrfo5.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0oj~fkdmzrfo5.css — 200 — 8.8 KiB — 101 ms — h3https://www.sennheiser.com/_next/static/chunks/127hdrxj12fr..csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/127hdrxj12fr..css — 200 — 8.7 KiB — 102 ms — h3https://www.sennheiser.com/_next/static/chunks/15tytnl8pzmq5.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/15tytnl8pzmq5.css — 200 — 9.9 KiB — 41 ms — h3https://www.sennheiser.com/_next/static/chunks/0vyo4bx.324pq.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0vyo4bx.324pq.css — 200 — 8.6 KiB — 106 ms — h3https://www.sennheiser.com/_next/static/chunks/0g_8ew~otbbyu.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0g_8ew~otbbyu.css — 200 — 5.4 KiB — 107 ms — h3https://www.sennheiser.com/_next/static/chunks/00a_j5jj2n0oh.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/00a_j5jj2n0oh.css — 200 — 810 B — 108 ms — h3https://cdn.optimizely.com/js/4875027175178240.jscdn.optimizely.com/js/4875027175178... https://cdn.optimizely.com/js/4875027175178240.js — 200 — 75.8 KiB — 110 ms — h2https://app.usercentrics.eu/browser-ui/latest/loader.jsapp.usercentrics.eu/browser-ui/late... https://app.usercentrics.eu/browser-ui/latest/loader.js — 200 — 10.8 KiB — 65 ms — h2https://www.gstatic.com/dialogflow-console/fast/messenger/bootstrap.js?v=1www.gstatic.com/dialogflow-console/... https://www.gstatic.com/dialogflow-console/fast/messenger/bootstrap.js?v=1 — 200 — 977 B — 91 ms — h2https://www.sennheiser.com/_next/static/chunks/0s6aco8y_s80a.jswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0s6aco8y_s80a.js — 200 — 9.4 KiB — 63 ms — h3https://www.sennheiser.com/_next/static/chunks/0p0wch357u~5f.jswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0p0wch357u~5f.js — 200 — 9.4 KiB — 46 ms — h3https://www.sennheiser.com/_next/static/chunks/02l79wwqbnvm_.jswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/02l79wwqbnvm_.js — 200 — 38.4 KiB — 46 ms — h3https://www.sennheiser.com/_next/static/chunks/0tpccgzewb7zp.jswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0tpccgzewb7zp.js — 200 — 69.5 KiB — 65 ms — h3https://www.sennheiser.com/_next/static/chunks/turbopack-15m.rgwn8ijb_.jswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/turbopack-15m.rgwn8ijb_.js — 200 — 4.4 KiB — 62 ms — h3https://www.sennheiser.com/_next/static/chunks/0zwlo7_m-6u8y.jswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0zwlo7_m-6u8y.js — 200 — 2.7 KiB — 64 ms — h3
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s FCP 3.4 s LCP 14.7 shttps://sennheiser.com// https://sennheiser.com/ — 301 — 121 B — 27 ms — h2https://www.sennheiser.com/www.sennheiser.com/ https://www.sennheiser.com/ — 307 — 829 B — 161 ms — h2https://www.sennheiser.com/en-dewww.sennheiser.com/en-de https://www.sennheiser.com/en-de — 200 — 58.3 KiB — 141 ms — h2https://assets.sennheiser.com/images/assets/HD_480_PRO_Product_Shot_Cutout_Isometric_View_01.png/Zz04ZjQ2YTc2NjExOGIxMWYxYjZiMGRhODFlODBkNGM4OQ==?width=750assets.sennheiser.com/images/assets... https://assets.sennheiser.com/images/assets/HD_480_PRO_Product_Shot_Cutout_Isometric_View_01.png/Zz04ZjQ2YTc2NjExOGIxMWYxYjZiMGRhODFlODBkNGM4OQ==?width=750 — 200 — 185.1 KiB — 250 ms — h2https://assets.sennheiser.com/images/assets/HD-480-PRO_homepage-block.jpeg/Zz0wOTNhMjcyNjNkN2IxMWYxYjk3MDllZjY1MzEwYmQyNA==?width=750assets.sennheiser.com/images/assets... https://assets.sennheiser.com/images/assets/HD-480-PRO_homepage-block.jpeg/Zz0wOTNhMjcyNjNkN2IxMWYxYjk3MDllZjY1MzEwYmQyNA==?width=750 — 200 — 302.5 KiB — 444 ms — h2https://www.sennheiser.com/_next/static/chunks/0udgwp.sjrfrj.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0udgwp.sjrfrj.css — 200 — 6.4 KiB — 79 ms — h3https://www.sennheiser.com/_next/static/chunks/06mlmbd2c.60_.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/06mlmbd2c.60_.css — 200 — 44.7 KiB — 97 ms — h3https://www.sennheiser.com/_next/static/chunks/0hpljjrfw5nnz.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0hpljjrfw5nnz.css — 200 — 9.6 KiB — 93 ms — h3https://www.sennheiser.com/_next/static/chunks/11t7vhu3czf~z.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/11t7vhu3czf~z.css — 200 — 8.9 KiB — 76 ms — 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h3https://www.sennheiser.com/_next/static/chunks/0eyptu_vb2gc3.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0eyptu_vb2gc3.css — 200 — 9.3 KiB — 100 ms — h3https://www.sennheiser.com/_next/static/chunks/0oj~fkdmzrfo5.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0oj~fkdmzrfo5.css — 200 — 8.8 KiB — 101 ms — h3https://www.sennheiser.com/_next/static/chunks/127hdrxj12fr..csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/127hdrxj12fr..css — 200 — 8.7 KiB — 102 ms — h3https://www.sennheiser.com/_next/static/chunks/15tytnl8pzmq5.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/15tytnl8pzmq5.css — 200 — 9.9 KiB — 41 ms — h3https://www.sennheiser.com/_next/static/chunks/0vyo4bx.324pq.csswww.sennheiser.com/_next/static/chu... https://www.sennheiser.com/_next/static/chunks/0vyo4bx.324pq.css — 200 — 8.6 KiB — 106 ms — 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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 4777ms · 772KB · €83/mo
www.sennheiser.com
Other
Costly
Execution 2246ms
Transfer 69 KB
Unused 33%
Monthly Cost €39/mo
www.sennheiser.com
Other
Costly
Execution 738ms
Transfer 58 KB
Monthly Cost €13/mo
Unattributable
Other
Costly
Execution 613ms
Transfer 0 KB
Monthly Cost €11/mo
Optimizely
A/B Testing
Costly
Execution 425ms
Transfer 76 KB
Unused 45%
Monthly Cost €7/mo
app.usercentrics.eu
Other
Costly
Execution 399ms
Transfer 121 KB
Unused 44%
Monthly Cost €7/mo
www.sennheiser.com
Other
Optional
Execution 198ms
Transfer 364 KB
Unused 95%
Monthly Cost €3/mo
www.sennheiser.com
Other
Optional
Execution 83ms
Transfer 17 KB
Monthly Cost €1/mo
www.sennheiser.com
Other
Optional
Execution 77ms
Transfer 67 KB
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • www.sennheiser.com adds 2246ms and costs ~€39/month
  • www.sennheiser.com adds 738ms and costs ~€13/month
  • Unattributable adds 613ms and costs ~€11/month
  • Optimizely adds 425ms and costs ~€7/month
  • app.usercentrics.eu adds 399ms and costs ~€7/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.sennheiser.com takes 2246ms 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.sennheiser.com takes 738ms 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 613ms 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

Optimizely takes 425ms 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

app.usercentrics.eu takes 399ms 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

95% of www.sennheiser.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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