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.
6.02 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
11.09 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
986 ms
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.
6.52 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.
13.55 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction6022ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.rtbf.be/ | 1941ms | 205ms | 239ms | 3rd |
| Unattributable | 1082ms | 172ms | 0ms | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/18-2db3bc3db671e157.js | 908ms | 724ms | 16ms | 3rd |
| https://cdns.eu1.gigya.com/js/gigya.js?apikey=3_kWKuPgcdAybqnqxq_MvHVk0-6PN8Zk8pIIkJM_yXOu-qLPDDsGOtIDFfpGivtbeO | 408ms | 304ms | 57ms | 3rd |
| https://sdk.privacy-center.org/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/sdk.22ecd6bfac93de604efec0b75b2c796ee1675f92.js | 388ms | 281ms | 58ms | 3rd |
| https://sdk.privacy-center.org/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/ui-web-fr-web.22ecd6bfac93de604efec0b75b2c796ee1675f92.js | 350ms | 116ms | 27ms | 3rd |
| https://static-oaos.rtbf.be/js/lazysizes/lazysizes.min.js | 201ms | 129ms | 2ms | 3rd |
| https://connect.facebook.net/en_US/bundle/sdk.js/ | 200ms | 168ms | 28ms | 3rd |
| https://gabe.hit.gemius.pl/xgemius.min.js | 185ms | 176ms | 6ms | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/app/(web)/layout-be8efa5307523b10.js | 148ms | 147ms | 0ms | 3rd |
Showing top 10 of 12 scripts
DJS BundlesAction75 scripts, 306 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://cdns.eu1.gigya.com/js/gigya.js?apikey=3_kWKuPgcdAybqnqxq_MvHVk0-6PN8Zk8pIIkJM_yXOu-qLPDDsGOtIDFfpGivtbeO | 238 KB | 136 KB (57%) | ✓ | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/5580-d9c0223d3a2e4389.js | 64 KB | 55 KB (86%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/bundle/sdk.js/ | 78 KB | 49 KB (63%) | ✓ | 3rd |
| https://sdk.privacy-center.org/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/sdk.22ecd6bfac93de604efec0b75b2c796ee1675f92.js | 102 KB | 45 KB (44%) | ✓ | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/8982-2de817e62cbcab4a.js | 23 KB | 20 KB (88%) | ✓ | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/8544-4b2ef8d343b522fb.js | 23 KB | — | ✓ | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/8994-c59f29b7252055af.js | 5 KB | — | ✓ | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/webpack-ce9baa13865cfb6d.js | 5 KB | — | ✓ | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/87c73c54-dd8d81ac9604067c.js | 53 KB | — | ✓ | 3rd |
| https://static-oaos.rtbf.be/14034624651/_next/static/chunks/18-2db3bc3db671e157.js | 45 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
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
DPage Weight InventoryAction111 resources · 1.4 MB · 306 KB savings availableFIX
~305.8 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 111 resources | 1.4 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BPage Weight Budget1.4 MB transferred, 111 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
BImage Optimization19 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 Loading1 fonts (30 KB)PASS
Web fonts
1
30 KB total
Render-blocking
0
of 1
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 Hints34 hints, 0 missing preconnectsPASS
Current Resource Hints
34 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall111 requests over 3830msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.rtbf.be www.rtbf.be | Other | 1941ms | 148 KB | — | €21/mo | Costly |
Unattributable Unattributable | Other | 1082ms | 0 KB | — | €12/mo | Costly |
static-oaos.rtbf.be static-oaos.rtbf.be | Other | 908ms | 45 KB | — | €10/mo | Costly |
cdns.eu1.gigya.com cdns.eu1.gigya.com | Other | 408ms | 238 KB | 57% | €4/mo | Costly |
sdk.privacy-center.org sdk.privacy-center.org | Other | 388ms | 102 KB | 44% | €4/mo | Costly |
sdk.privacy-center.org sdk.privacy-center.org | Other | 350ms | 56 KB | — | €4/mo | Costly |
static-oaos.rtbf.be static-oaos.rtbf.be | Other | 201ms | 4 KB | — | €2/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 200ms | 78 KB | 63% | €2/mo | Costly |
gabe.hit.gemius.pl gabe.hit.gemius.pl | Other | 185ms | 19 KB | — | €2/mo | Optional |
static-oaos.rtbf.be static-oaos.rtbf.be | Other | 148ms | 1 KB | — | €2/mo | Optional |
static-oaos.rtbf.be static-oaos.rtbf.be | Other | 119ms | 23 KB | — | €1/mo | Optional |
static-oaos.rtbf.be static-oaos.rtbf.be | Other | 92ms | 53 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- www.rtbf.be adds 1941ms and costs ~€21/month
- Unattributable adds 1082ms and costs ~€12/month
- static-oaos.rtbf.be adds 908ms and costs ~€10/month
- cdns.eu1.gigya.com adds 408ms and costs ~€4/month
- sdk.privacy-center.org adds 388ms and costs ~€4/month
- sdk.privacy-center.org adds 350ms and costs ~€4/month
- static-oaos.rtbf.be adds 201ms and costs ~€2/month
- Facebook Pixel adds 200ms 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.rtbf.be takes 1941ms 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 1082ms 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-oaos.rtbf.be takes 908ms 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
cdns.eu1.gigya.com takes 408ms 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
57% of cdns.eu1.gigya.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
sdk.privacy-center.org takes 388ms 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 350ms 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-oaos.rtbf.be takes 201ms 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
Facebook Pixel takes 200ms 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 Facebook Pixel'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