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.
930 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.97 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
5 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.417
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.24 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.
1.98 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS BundlesAction88 scripts, 963 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.aerzteblatt.de/_next/static/chunks/9720-4b9fbf10fcede198.js | 0 KB | 86 KB (78%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/9720-4b9fbf10fcede198.js | 33 KB | 86 KB (78%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/161-714567f83460a491.js | 26 KB | 63 KB (83%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/161-714567f83460a491.js | 0 KB | 63 KB (83%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/58474bfb-444aaef4baa375e2.js | 83 KB | 58 KB (71%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/pages/_app-f9fc4fff9cff59ca.js | 104 KB | 55 KB (53%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/9288-d1ea9098ffef97f8.js | 16 KB | 54 KB (96%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/9288-d1ea9098ffef97f8.js | 0 KB | 54 KB (96%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/5437-ab84f868d6822720.js | 0 KB | 46 KB (93%) | ✓ | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/5437-ab84f868d6822720.js | 16 KB | 46 KB (93%) | ✓ | 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 InventoryAction153 resources · 1.5 MB · 963 KB savings availableFIX
~963.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 153 resources | 1.5 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BPage Weight Budget1.5 MB transferred, 153 requestsREVIEW
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
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
BJS Execution Cost674ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.aerzteblatt.de/_next/static/chunks/framework-ff6a7c7c83b61e4d.js | 241ms | 224ms | 4ms | 3rd |
| https://www.aerzteblatt.de/ | 213ms | 23ms | 1ms | 3rd |
| Unattributable | 118ms | 6ms | 0ms | 3rd |
| https://www.aerzteblatt.de/_next/static/chunks/main-77c656528850346a.js | 102ms | 87ms | 3ms | 3rd |
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Image Optimization14 images, 0 KB saveablePASS
A+Font Loading6 fonts (116 KB)PASS
Web fonts
6
116 KB total
Render-blocking
0
of 6
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
Network Waterfall153 requests over 1401msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.aerzteblatt.de www.aerzteblatt.de | Other | 241ms | 56 KB | 38% | €3/mo | Costly |
www.aerzteblatt.de www.aerzteblatt.de | Other | 213ms | 60 KB | — | €2/mo | Costly |
Unattributable Unattributable | Other | 118ms | 0 KB | — | €1/mo | Optional |
www.aerzteblatt.de www.aerzteblatt.de | Other | 102ms | 38 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- www.aerzteblatt.de adds 241ms and costs ~€3/month
- www.aerzteblatt.de adds 213ms and costs ~€2/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.aerzteblatt.de takes 241ms 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.aerzteblatt.de takes 213ms 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