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https://government.nl

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
86
GRADE
B
FIX
2
REVIEW
3
PASS
8
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
67
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
96
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

1.92 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

3.31 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

11 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.034

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

3.44 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.

3.31 s

Page Load Progression

978 ms
2.0 s
2.9 s
3.9 s
4.9 s
5.9 s
6.8 s
7.8 s
Checks
15
8 PASS 3 REVIEW 2 FIX
D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (893.3 KiB of 893.6 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

C
Image Optimization
Action
5 images, 0 KB saveable
REVIEW
5 images, 0 KB saveable
Warning::
https://www.government.nl/binaries/medium/content/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.government.nl/binaries/content/gallery... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.government.nl/binaries/medium/content/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.government.nl/binaries/medium/content/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
5 images 472 KB
0 oversized -0 KB
5 legacy format
4 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

B
JS Bundles
7 scripts, 57 KB unused
REVIEW
7 scripts, 57 KB unused
Warning::
https://statistiek.rijksoverheid.nl/containers/179...: 36 KB unused (48%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.government.nl/webfiles/1750011834072/b...: 21 KB unused (47%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 57 KB
57 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://statistiek.rijksoverheid.nl/containers/17953060-0014-4821-b579-e7b24c408376.js76 KB36 KB (48%)✓3rd
https://www.government.nl/webfiles/1750011834072/behaviour/core.js44 KB21 KB (47%)✓3rd
https://www.government.nl/binaries/content/assets/government/javascript/government-survey-bar.min-20230526.js2 KB—✓3rd
https://statistiek.rijksoverheid.nl/ppms.js26 KB—✓3rd
https://survey-deploy.platformrijksoverheid.nl/js/pastease.js14 KB—✓3rd
https://www.government.nl/webfiles/1750011834072/behaviour/shared-ro/jquery-ui.js11 KB—✓3rd
https://www.government.nl/webfiles/1750011834072/behaviour/shared-ro/img-helpers.js6 KB—✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

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.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Page Weight Budget
894 KB transferred, 23 requests
PASS
894 KB transferred, 23 requests
Info::
Page weighs 1.6 MB (894 KB transferred)
Info::
23 HTTP requests
Info::
Estimated 0.18 g CO2 per page load
894 KB / 2.4 MB budget
894 KB transferred
23 requests
0.18 g CO2 per page load
Images 471.7 KiB 53%
Fonts 181.7 KiB 20%
JavaScript 179.2 KiB 20%
CSS 50.0 KiB 6%
HTML 7.4 KiB 1%
Other 2.4 KiB 0%
Other 1.2 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Under budget
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
JS Execution Cost
361ms total JS execution
PASS
361ms total JS execution
Info::
https://www.government.nl/: 128ms CPU time
Info::
Unattributable: 95ms CPU time
Info::
https://statistiek.rijksoverheid.nl/containers/179...: 80ms CPU time
Info::
https://www.government.nl/webfiles/1750011834072/b...: 58ms CPU time
Warning::
Third-party scripts: 361ms (100% of total)

Main Thread Breakdown

Script Evaluation 35% Other 29% Style & Layout 21% Script Parsing & Compilation 7% Rendering 5% Parse HTML & CSS 3%
ScriptTotalScriptingParse/CompileParty
https://www.government.nl/128ms3ms1ms3rd
Unattributable95ms2ms0ms3rd
https://statistiek.rijksoverheid.nl/containers/17953060-0014-4821-b579-e7b24c408376.js80ms62ms14ms3rd
https://www.government.nl/webfiles/1750011834072/behaviour/core.js58ms42ms8ms3rd
A+
Font Loading
4 fonts (182 KB)
PASS
4 fonts (182 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

182 KB total

Render-blocking

0

of 4

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s 4.0 s FCP 1.9 s LCP 3.3 shttps://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Regular.woff2RO-SansWebText-Regular.... https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Regular.woff2 — 53.6 KiB — 1.6 s — font-display: swaphttps://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/rijks-sans-regular.woff2rijks-sans-regular.woff2 https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/rijks-sans-regular.woff2 — 75.1 KiB — 2.1 s — font-display: swaphttps://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Bold.woff2RO-SansWebText-Bold.woff2 https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Bold.woff2 — 47.9 KiB — 2.3 s — font-display: swaphttps://www.government.nl/webfiles/1750011834072/presentation/shared-ro/icons/ro-icons-2.4.woff2ro-icons-2.4.woff2 https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/icons/ro-icons-2.4.woff2 — 5.1 KiB — 2.3 s — font-display: swap
RO-SansWebText-Regular.... woff2 swap
Size 54 KB
Load time 1.6 s
Start 1.7 s
Risk FOUT — text flashes from fallback to web font
rijks-sans-regular.woff2 woff2 swap
Size 75 KB
Load time 2.1 s
Start 1.7 s
Risk FOUT — text flashes from fallback to web font
RO-SansWebText-Bold.woff2 woff2 swap
Size 48 KB
Load time 2.3 s
Start 1.7 s
Risk FOUT — text flashes from fallback to web font
ro-icons-2.4.woff2 woff2 swap
Size 5 KB
Load time 2.3 s
Start 1.7 s
Risk FOUT — text flashes from fallback to web font
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 Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A
Page Weight Inventory
23 resources · 894 KB · 57 KB savings available
PASS
23 resources · 894 KB · 57 KB savings available
Info::
Within 1MB page-weight target
Got: 894 KB
Info::
~57 KB of savings available
Warning::
22 third-party resources (100% of weight)
Info::
1 resources over 200KB
23 resources · 893.6 KiB · 22 third-party Within 1MB page-weight target
Image 53% · 473.8 KiB
Font 20% · 181.7 KiB
JavaScript 20% · 179.2 KiB
CSS 6% · 50.0 KiB
Document 1% · 7.7 KiB
Other 0% · 1.2 KiB

~56.8 KiB of savings available

Remove unused JavaScript: 56.8 KiB
Network Waterfall
23 requests over 6964ms
INFO
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s FCP 1.9 s LCP 3.3 shttps://government.nl// https://government.nl/ — 301 — 302 B — 875 ms — h2https://www.government.nl/www.government.nl/ https://www.government.nl/ — 200 — 7.4 KiB — 242 ms — h2https://www.government.nl/webfiles/1750011834072/presentation/responsive.csswww.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/presentation/responsive.css — 200 — 49.2 KiB — 481 ms — h2https://www.government.nl/webfiles/1750011834072/presentation/themes/logoblauw.csswww.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/presentation/themes/logoblauw.css — 200 — 754 B — 478 ms — h2https://www.government.nl/webfiles/1750011834072/behaviour/core.jswww.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/behaviour/core.js — 200 — 44.1 KiB — 949 ms — h2https://www.government.nl/binaries/content/gallery/government/channel-afbeeldingen/logos/beeldmerk-rijksoverheid-desktop.svgwww.government.nl/binaries/content/... https://www.government.nl/binaries/content/gallery/government/channel-afbeeldingen/logos/beeldmerk-rijksoverheid-desktop.svg — 200 — 6.5 KiB — 4.3 s — h2https://www.government.nl/binaries/widescreen/content/gallery/government/content-afbeeldingen/home/bollenvelden.jpgwww.government.nl/binaries/widescre... https://www.government.nl/binaries/widescreen/content/gallery/government/content-afbeeldingen/home/bollenvelden.jpg — 200 — 202.1 KiB — 4.8 s — h2https://www.government.nl/binaries/medium/content/gallery/government/banners-en-uitgelichtjes/home/2023/rented-housing.jpgwww.government.nl/binaries/medium/c... https://www.government.nl/binaries/medium/content/gallery/government/banners-en-uitgelichtjes/home/2023/rented-housing.jpg — 200 — 156.3 KiB — 5.3 s — h2https://www.government.nl/binaries/medium/content/gallery/government/content-afbeeldingen/topics/travelling-to-the-netherlands/dutch-bulb-fields-hero.jpgwww.government.nl/binaries/medium/c... https://www.government.nl/binaries/medium/content/gallery/government/content-afbeeldingen/topics/travelling-to-the-netherlands/dutch-bulb-fields-hero.jpg — 200 — 70.2 KiB — 4.8 s — h2https://www.government.nl/binaries/medium/content/gallery/government/banners-en-uitgelichtjes/home/2025/requirements-for-id-photoswww.government.nl/binaries/medium/c... https://www.government.nl/binaries/medium/content/gallery/government/banners-en-uitgelichtjes/home/2025/requirements-for-id-photos — 200 — 36.6 KiB — 3.8 s — h2https://statistiek.rijksoverheid.nl/containers/17953060-0014-4821-b579-e7b24c408376.jsstatistiek.rijksoverheid.nl/contain... https://statistiek.rijksoverheid.nl/containers/17953060-0014-4821-b579-e7b24c408376.js — 200 — 76.4 KiB — 890 ms — h2https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Regular.woff2www.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Regular.woff2 — 200 — 53.6 KiB — 1.6 s — h2https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/rijks-sans-regular.woff2www.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/rijks-sans-regular.woff2 — 200 — 75.1 KiB — 2.1 s — h2https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Bold.woff2www.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Bold.woff2 — 200 — 47.9 KiB — 2.3 s — h2https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/icons/ro-icons-2.4.woff2www.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/presentation/shared-ro/icons/ro-icons-2.4.woff2 — 200 — 5.1 KiB — 2.3 s — h2https://www.government.nl/binaries/content/assets/government/javascript/government-survey-bar.min-20230526.jswww.government.nl/binaries/content/... https://www.government.nl/binaries/content/assets/government/javascript/government-survey-bar.min-20230526.js — 200 — 2.2 KiB — 3.8 s — h2https://statistiek.rijksoverheid.nl/ppms.jsstatistiek.rijksoverheid.nl/ppms.js https://statistiek.rijksoverheid.nl/ppms.js — 200 — 25.9 KiB — 183 ms — h2https://survey-deploy.platformrijksoverheid.nl/js/pastease.jssurvey-deploy.platformrijksoverheid... https://survey-deploy.platformrijksoverheid.nl/js/pastease.js — 200 — 14.3 KiB — 23 ms — h2https://survey-deploy.platformrijksoverheid.nl/config/UHAlMTIl57IJFOF8ZREXWB1gpMRLgfI3Vpii8GZFsurvey-deploy.platformrijksoverheid... https://survey-deploy.platformrijksoverheid.nl/config/UHAlMTIl57IJFOF8ZREXWB1gpMRLgfI3Vpii8GZF — 200 — 1.2 KiB — 9 ms — h2https://statistiek.rijksoverheid.nl/ppms.phpstatistiek.rijksoverheid.nl/ppms.ph... https://statistiek.rijksoverheid.nl/ppms.php — 202 — 0 B — 180 ms — h2https://www.government.nl/webfiles/1750011834072/behaviour/shared-ro/jquery-ui.jswww.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/behaviour/shared-ro/jquery-ui.js — 200 — 10.9 KiB — 989 ms — h2https://www.government.nl/webfiles/1750011834072/behaviour/shared-ro/img-helpers.jswww.government.nl/webfiles/17500118... https://www.government.nl/webfiles/1750011834072/behaviour/shared-ro/img-helpers.js — 200 — 5.5 KiB — 240 ms — h2https://www.government.nl/binaries/content/assets/government/iconen/favicon.icowww.government.nl/binaries/content/... https://www.government.nl/binaries/content/assets/government/iconen/favicon.ico — 200 — 2.1 KiB — 239 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 361ms · 128KB · €4/mo
www.government.nl
Other
Optional
Execution 128ms
Transfer 7 KB
Monthly Cost €1/mo
Unattributable
Other
Optional
Execution 95ms
Transfer 0 KB
Monthly Cost €1/mo
statistiek.rijksoverheid.nl
Other
Optional
Execution 80ms
Transfer 76 KB
Unused 48%
Monthly Cost €1/mo
www.government.nl
Other
Optional
Execution 58ms
Transfer 44 KB
Unused 47%
Monthly Cost €1/mo

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

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

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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