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.
4.02 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
12.93 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
2.19 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
2.081
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
8.77 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.
16.36 s
Page Load Progression
DPage Weight BudgetAction2.2 MB transferred, 78 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
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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction8812ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://static.spektrum.de/js_css/assets/js/app.js | 2333ms | 1278ms | 78ms | 3rd |
| https://www.spektrum.de/ | 1770ms | 37ms | 6ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NV9D2M | 1091ms | 866ms | 84ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202604.1.0/otBannerSdk.js | 783ms | 458ms | 98ms | 3rd |
| Unattributable | 724ms | 14ms | 0ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202604.1.0/otTCF.js | 648ms | 575ms | 11ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-YXNVZ6NX0G&cx=c>m=4e64k1h1 | 456ms | 387ms | 64ms | 3rd |
| https://static.spektrum.de/js_css/iqd/cdn_spektrum_mob_digt/live/iqadcontroller.js | 414ms | 203ms | 110ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/otSDKStub.js?did=69405b66-21db-433c-a550-4b18074a0f51 | 180ms | 135ms | 4ms | 3rd |
| https://assets.poool.fr/access.min.js | 157ms | 135ms | 18ms | 3rd |
Showing top 10 of 13 scripts
DPage Weight InventoryAction78 resources · 2.2 MB · 295 KB savings availableFIX
~294.9 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 78 resources | 2.2 MiB | ||||||
BImage Optimization10 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
CJS BundlesAction22 scripts, 295 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://static.spektrum.de/js_css/assets/js/app.js | 140 KB | 94 KB (67%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NV9D2M | 171 KB | 74 KB (44%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-YXNVZ6NX0G&cx=c>m=4e64k1h1 | 172 KB | 65 KB (38%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202604.1.0/otBannerSdk.js | 131 KB | 62 KB (47%) | ✓ | 3rd |
| https://www.spektrum.de/js_css/ouibounce/ouibounce.min.js | 1 KB | — | ✓ | 3rd |
| https://assets.poool.fr/vendor-audit.min.js | 1 KB | — | ✓ | 3rd |
| https://static.spektrum.de/js_css/iqd/cdn_spektrum_mob_digt/live/iqadcontroller.js | 69 KB | — | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202604.1.0/otTCF.js | 18 KB | — | ✓ | 3rd |
| https://assets.poool.fr/engage.min.js | 19 KB | — | ✓ | 3rd |
| https://assets.poool.fr/access.min.js | 31 KB | — | ✓ | 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
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 Loading15 fonts (497 KB)PASS
Web fonts
15
497 KB total
Render-blocking
0
of 15
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
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
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 ~136 KB and ~272 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints12 hints, 0 missing preconnectsPASS
Current Resource Hints
12 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
AHTTP Cachingmax-age=86400 (1 day)PASS
max-age=86400
| Directive | Value | Meaning |
|---|---|---|
| max-age | 86400 | Cache for 1 day |
Network Waterfall78 requests over 4214msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
static.spektrum.de static.spektrum.de | Other | 2333ms | 140 KB | 67% | €25/mo | Costly |
www.spektrum.de www.spektrum.de | Other | 1770ms | 33 KB | — | €19/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 1091ms | 171 KB | 44% | €12/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 783ms | 131 KB | 47% | €8/mo | Essential |
Unattributable Unattributable | Other | 724ms | 0 KB | — | €8/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 648ms | 18 KB | — | €7/mo | Essential |
Google Tag Manager www.googletagmanager.com | Tag Manager | 456ms | 172 KB | 38% | €5/mo | Costly |
static.spektrum.de static.spektrum.de | Other | 414ms | 69 KB | — | €4/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 180ms | 9 KB | — | €2/mo | Essential |
assets.poool.fr assets.poool.fr | Other | 157ms | 31 KB | — | €2/mo | Optional |
static.spektrum.de static.spektrum.de | Other | 105ms | 29 KB | — | €1/mo | Optional |
assets.poool.fr assets.poool.fr | Other | 89ms | 10 KB | — | €1/mo | Optional |
assets.poool.fr assets.poool.fr | Other | 60ms | 3 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- static.spektrum.de adds 2333ms and costs ~€25/month
- www.spektrum.de adds 1770ms and costs ~€19/month
- Google Tag Manager adds 1091ms and costs ~€12/month
- Unattributable adds 724ms and costs ~€8/month
- Google Tag Manager adds 456ms and costs ~€5/month
- static.spektrum.de adds 414ms 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
static.spektrum.de takes 2333ms 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
67% of static.spektrum.de'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.spektrum.de takes 1770ms 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 1091ms 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 724ms 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 456ms 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
static.spektrum.de takes 414ms 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