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.
14.09 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
32.47 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
412 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.
14.09 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.
32.49 s
Page Load Progression
FPage Weight BudgetAction7.3 MB transferred, 147 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
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 CostAction5221ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 915ms | 43ms | 0ms | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 828ms | 734ms | 72ms | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604160201/pubads_impl.js?cb=31097945 | 820ms | 553ms | 87ms | 3rd |
| https://pagead2.googlesyndication.com/pagead/managed/js/activeview/current/ufs_web_display.js | 729ms | 623ms | 60ms | 3rd |
| https://www.iii.org/ | 330ms | 227ms | 9ms | 3rd |
| https://www.iii.org/sites/all/modules/jquery_update/replace/jquery/1.12/jquery.min.js?v=1.12.4 | 298ms | 149ms | 23ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-RLMX21NG0L&cx=c>m=4e64k1 | 275ms | 239ms | 34ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-59PD8RW | 260ms | 220ms | 37ms | 3rd |
| https://connect.facebook.net/en_GB/bundle/sdk.js/ | 166ms | 121ms | 38ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-EK9ELW4PP2&cx=c>m=4e64k0 | 162ms | 126ms | 35ms | 3rd |
Showing top 10 of 15 scripts
FJS BundlesAction63 scripts, 1.3 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 0 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 0 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 | 362 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.iii.org/sites/all/themes/iii_responsive/js/jquery-ui-1.12.1.custom/jquery-ui.js?t7dqau | 155 KB | 123 KB (79%) | ✗ | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604160201/pubads_impl.js?cb=31097945 | 188 KB | 103 KB (55%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-59PD8RW | 163 KB | 81 KB (50%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-EK9ELW4PP2&cx=c>m=4e64k0 | 161 KB | 69 KB (43%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-RLMX21NG0L&cx=c>m=4e64k1 | 154 KB | 65 KB (42%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=UA-542962-2 | 125 KB | 63 KB (50%) | ✓ | 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 InventoryAction147 resources · 7.3 MB · 1.3 MB savings availableFIX
~1.3 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 147 resources | 7.3 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction34 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
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
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
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 (191 KB)PASS
Web fonts
7
191 KB total
Render-blocking
0
of 7
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
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall147 requests over 2900msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 915ms | 0 KB | — | €10/mo | Costly |
www.gstatic.com www.gstatic.com | Other | 828ms | 0 KB | 49% | €9/mo | Costly |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 820ms | 188 KB | 55% | €9/mo | Costly |
pagead2.googlesyndication.com pagead2.googlesyndication.com | Other | 729ms | 0 KB | 43% | €8/mo | Costly |
www.iii.org www.iii.org | Other | 330ms | 18 KB | — | €4/mo | Costly |
www.iii.org www.iii.org | Other | 298ms | 39 KB | — | €3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 275ms | 154 KB | 42% | €3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 260ms | 163 KB | 50% | €3/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 166ms | 78 KB | 66% | €2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 162ms | 161 KB | 43% | €2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 155ms | 125 KB | 50% | €2/mo | Optional |
www.iii.org www.iii.org | Other | 92ms | 155 KB | 79% | €1/mo | Optional |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 85ms | 34 KB | — | €1/mo | Optional |
LinkedIn Insight snap.licdn.com | Advertising | 53ms | 19 KB | — | €1/mo | Optional |
Google Analytics www.google-analytics.com | Analytics | 52ms | 21 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 915ms and costs ~€10/month
- www.gstatic.com adds 828ms and costs ~€9/month
- securepubads.g.doubleclick.net adds 820ms and costs ~€9/month
- pagead2.googlesyndication.com adds 729ms and costs ~€8/month
- www.iii.org adds 330ms and costs ~€4/month
- www.iii.org adds 298ms and costs ~€3/month
- Google Tag Manager adds 275ms and costs ~€3/month
- Google Tag Manager adds 260ms and costs ~€3/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
Unattributable takes 915ms 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.gstatic.com takes 828ms 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 820ms 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
55% 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
pagead2.googlesyndication.com takes 729ms 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.iii.org takes 330ms 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.iii.org takes 298ms 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 275ms 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 260ms 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
66% 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
50% 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
79% of www.iii.org'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