Performance
· 15 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.
3.03 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
4.06 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
417 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.659
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
3.92 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.
5.51 s
Page Load Progression
FPage Weight BudgetAction5.3 MB transferred, 189 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
Subset fonts to include only used characters, or switch to system font stacks.
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.
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 CostAction3736ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://open.spotifycdn.com/cdn/build/web-player/web-player.42122f83.js | 2095ms | 1259ms | 131ms | 3rd |
| Unattributable | 482ms | 112ms | 0ms | 3rd |
| https://open.spotifycdn.com/cdn/build/web-player/encore~web-player.2731d7c8.js | 338ms | 322ms | 14ms | 3rd |
| https://open.spotifycdn.com/cdn/build/web-player/vendor~web-player.bf1f6caf.js | 286ms | 218ms | 45ms | 3rd |
| https://open.spotify.com/ | 252ms | 1ms | 0ms | 1st |
| https://www.googletagmanager.com/gtm.js?id=GTM-PZHN3VD | 123ms | 107ms | 14ms | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 81ms | 50ms | 29ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202601.2.0/otBannerSdk.js | 79ms | 53ms | 21ms | 3rd |
FJS BundlesAction61 scripts, 1.7 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://open.spotifycdn.com/cdn/build/web-player/web-player.42122f83.js | 1046 KB | 635 KB (63%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 362 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 362 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 0 KB | 177 KB (49%) | ✓ | 3rd |
| https://open.spotifycdn.com/cdn/build/web-player/vendor~web-player.bf1f6caf.js | 233 KB | 175 KB (75%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PZHN3VD | 160 KB | 83 KB (52%) | ✓ | 3rd |
| https://open.spotifycdn.com/cdn/build/web-player/encore~web-player.2731d7c8.js | 95 KB | 74 KB (78%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202601.2.0/otBannerSdk.js | 128 KB | 74 KB (58%) | ✓ | 3rd |
| https://open.spotifycdn.com/cdn/build/web-player/dwp-panel-section.36a80850.js | 59 KB | 51 KB (88%) | ✓ | 3rd |
| https://open.spotifycdn.com/cdn/build/web-player/xpui-root-dialogs.fdcb51f2.js | 56 KB | 43 KB (78%) | ✓ | 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 InventoryAction189 resources · 5.3 MB · 1.7 MB savings availableFIX
~1.7 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 189 resources | 5.3 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization55 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 Loading7 fonts (935 KB)PASS
Web fonts
7
935 KB total
Render-blocking
0
of 7
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~368 KB and ~736 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall189 requests over 6058msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
open.spotifycdn.com open.spotifycdn.com | Other | 2095ms | 1046 KB | 63% | €23/mo | Costly |
Unattributable Unattributable | Other | 482ms | 0 KB | — | €5/mo | Costly |
open.spotifycdn.com open.spotifycdn.com | Other | 338ms | 95 KB | 78% | €4/mo | Costly |
open.spotifycdn.com open.spotifycdn.com | Other | 286ms | 233 KB | 75% | €3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 123ms | 160 KB | 52% | €1/mo | Optional |
www.gstatic.com www.gstatic.com | Other | 81ms | 0 KB | 49% | €1/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 79ms | 128 KB | 58% | €1/mo | Essential |
These scripts may cost more than they're worth
- open.spotifycdn.com adds 2095ms and costs ~€23/month
- Unattributable adds 482ms and costs ~€5/month
- open.spotifycdn.com adds 338ms and costs ~€4/month
- open.spotifycdn.com adds 286ms and costs ~€3/month
93% 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
open.spotifycdn.com takes 2095ms 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
63% of open.spotifycdn.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
Unattributable takes 482ms 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
open.spotifycdn.com takes 338ms 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
78% of open.spotifycdn.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
open.spotifycdn.com takes 286ms 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
75% of open.spotifycdn.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
52% of Google Tag Manager'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
58% 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