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.
3.64 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
11.72 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
3.53 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
10.75 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.
31.91 s
Page Load Progression
FPage Weight BudgetAction11.0 MB transferred, 131 requestsFIX
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
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
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 CostAction13209ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.telegraaf.nl/ | 2842ms | 199ms | 7ms | 3rd |
| https://www.telegraaf.nl/_next/static/chunks/framework-136df7d2ca0cb23d.js | 2427ms | 2213ms | 27ms | 3rd |
| Unattributable | 1962ms | 245ms | 0ms | 3rd |
| https://sdk.privacy-center.org/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/ui-web-nl-web.22ecd6bfac93de604efec0b75b2c796ee1675f92.js | 1577ms | 1321ms | 38ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TCTRVFNT>m_auth=luqLJVHzZCZ8FRNw0psBqA>m_preview=env-1>m_cookies_win=x | 443ms | 338ms | 74ms | 3rd |
| https://sdk.privacy-center.org/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/sdk.22ecd6bfac93de604efec0b75b2c796ee1675f92.js | 439ms | 336ms | 47ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-4S0SMBYPTG&cx=c>m=4e64k0 | 395ms | 332ms | 58ms | 3rd |
| https://cdn.kaching.eu.com/prebid/10.21.0/nl/prebid.js | 353ms | 194ms | 158ms | 3rd |
| https://www.telegraaf.nl/cdn-cgi/challenge-platform/scripts/jsd/main.js | 341ms | 272ms | 3ms | 3rd |
| https://www.telegraaf.nl/_next/static/chunks/pages/index-fa48c3b5e14ae0b0.js | 299ms | 298ms | 0ms | 3rd |
Showing top 10 of 23 scripts
FJS BundlesAction48 scripts, 1.0 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604160201/pubads_impl.js?cb=31097945 | 188 KB | 130 KB (69%) | ✓ | 3rd |
| https://www.telegraaf.nl/_next/static/chunks/pages/_app-9f68971ab19cc48d.js | 198 KB | 119 KB (60%) | ✓ | 3rd |
| https://prod-tmg.mhtr.be/public/tr/tracker.min.js | 157 KB | 112 KB (72%) | ✓ | 3rd |
| https://www.telegraaf.nl/_next/static/chunks/2248-e36bd15ff5938687.js | 180 KB | 111 KB (61%) | ✓ | 3rd |
| https://cdn.kaching.eu.com/prebid/10.21.0/nl/prebid.js | 138 KB | 101 KB (74%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TCTRVFNT>m_auth=luqLJVHzZCZ8FRNw0psBqA>m_preview=env-1>m_cookies_win=x | 172 KB | 68 KB (39%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-4S0SMBYPTG&cx=c>m=4e64k0 | 161 KB | 66 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PLCMDRH4>m_auth=CxJv3UN7_Ke3WjOi3uYfVQ>m_preview=env-1>m_cookies_win=x | 142 KB | 53 KB (37%) | ✓ | 3rd |
| https://www.telegraaf.nl/_next/static/chunks/427ddc6b-10f35a46b3e2cd4b.js | 80 KB | 51 KB (67%) | ✓ | 3rd |
| https://sdk.privacy-center.org/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/sdk.22ecd6bfac93de604efec0b75b2c796ee1675f92.js | 103 KB | 44 KB (43%) | ✓ | 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 InventoryAction131 resources · 11.0 MB · 1.0 MB savings availableFIX
~1.0 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 131 resources | 11.0 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction41 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
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
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
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
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
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
A+Text CompressionAll text resources are compressedPASS
A+Font Loading6 fonts (540 KB)PASS
Web fonts
6
540 KB total
Render-blocking
0
of 6
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
- 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 ~247 KB and ~494 ms
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
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall131 requests over 7053msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.telegraaf.nl www.telegraaf.nl | Other | 2842ms | 104 KB | — | €31/mo | Costly |
www.telegraaf.nl www.telegraaf.nl | Other | 2427ms | 65 KB | 44% | €26/mo | Costly |
Unattributable Unattributable | Other | 1962ms | 0 KB | — | €21/mo | Costly |
sdk.privacy-center.org sdk.privacy-center.org | Other | 1577ms | 55 KB | — | €17/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 443ms | 172 KB | 39% | €5/mo | Costly |
sdk.privacy-center.org sdk.privacy-center.org | Other | 439ms | 103 KB | 43% | €5/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 395ms | 161 KB | 41% | €4/mo | Costly |
cdn.kaching.eu.com cdn.kaching.eu.com | Other | 353ms | 138 KB | 74% | €4/mo | Costly |
www.telegraaf.nl www.telegraaf.nl | Other | 341ms | 0 KB | — | €4/mo | Costly |
www.telegraaf.nl www.telegraaf.nl | Other | 299ms | 0 KB | — | €3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 287ms | 142 KB | 37% | €3/mo | Costly |
prod-tmg.mhtr.be prod-tmg.mhtr.be | Other | 277ms | 157 KB | 72% | €3/mo | Costly |
boot.pbstck.com boot.pbstck.com | Other | 264ms | 1 KB | — | €3/mo | Costly |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 238ms | 188 KB | 69% | €3/mo | Costly |
www.telegraaf.nl www.telegraaf.nl | Other | 229ms | 198 KB | 60% | €2/mo | Costly |
sdk.privacy-center.org sdk.privacy-center.org | Other | 187ms | 1 KB | — | €2/mo | Optional |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 132ms | 34 KB | 71% | €1/mo | Optional |
aswpsdkus.com aswpsdkus.com | Other | 109ms | 40 KB | 73% | €1/mo | Optional |
www.telegraaf.nl www.telegraaf.nl | Other | 96ms | 37 KB | — | €1/mo | Optional |
sdk.privacy-center.org sdk.privacy-center.org | Other | 86ms | 135 KB | — | €1/mo | Optional |
cdn.cxense.com cdn.cxense.com | Other | 85ms | 38 KB | 60% | €1/mo | Optional |
www.telegraaf.nl www.telegraaf.nl | Other | 81ms | 180 KB | 61% | €1/mo | Optional |
www.telegraaf.nl www.telegraaf.nl | Other | 60ms | 2 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- www.telegraaf.nl adds 2842ms and costs ~€31/month
- www.telegraaf.nl adds 2427ms and costs ~€26/month
- Unattributable adds 1962ms and costs ~€21/month
- sdk.privacy-center.org adds 1577ms and costs ~€17/month
- Google Tag Manager adds 443ms and costs ~€5/month
- sdk.privacy-center.org adds 439ms and costs ~€5/month
- Google Tag Manager adds 395ms and costs ~€4/month
- cdn.kaching.eu.com adds 353ms and costs ~€4/month
- www.telegraaf.nl adds 341ms and costs ~€4/month
- www.telegraaf.nl adds 299ms and costs ~€3/month
- Google Tag Manager adds 287ms and costs ~€3/month
- prod-tmg.mhtr.be adds 277ms and costs ~€3/month
- boot.pbstck.com adds 264ms and costs ~€3/month
- securepubads.g.doubleclick.net adds 238ms and costs ~€3/month
- www.telegraaf.nl adds 229ms 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.telegraaf.nl takes 2842ms 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.telegraaf.nl takes 2427ms 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 1962ms 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
sdk.privacy-center.org takes 1577ms 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 443ms 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
sdk.privacy-center.org takes 439ms 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 395ms 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
cdn.kaching.eu.com takes 353ms 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
74% of cdn.kaching.eu.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
www.telegraaf.nl takes 341ms 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.telegraaf.nl takes 299ms 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 287ms 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
prod-tmg.mhtr.be takes 277ms 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
72% of prod-tmg.mhtr.be'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
boot.pbstck.com takes 264ms 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
securepubads.g.doubleclick.net takes 238ms 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
69% of securepubads.g.doubleclick.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
www.telegraaf.nl takes 229ms 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
60% of www.telegraaf.nl'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
71% of securepubads.g.doubleclick.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
73% of aswpsdkus.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
60% of cdn.cxense.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
61% of www.telegraaf.nl'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