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https://rijksoverheid.nl

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
86
GRADE
B
FIX
2
REVIEW
4
PASS
9
INFO
2

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

Mobile Desktop
56
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.
100
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.

3.68 s

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

9.40 s

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

244 ms

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

0.047

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

7.56 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.

9.40 s

Page Load Progression

934 ms
1.9 s
2.8 s
3.7 s
4.7 s
5.6 s
6.5 s
7.5 s
Checks
17
9 PASS 4 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 (1006.3 KiB of 1006.6 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.rijksoverheid.nl/binaries/content/gall... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.rijksoverheid.nl/binaries/medium/conte... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.rijksoverheid.nl/binaries/medium/conte... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.rijksoverheid.nl/binaries/medium/conte... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
5 images 503 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

C
JS Execution Cost
Action
1684ms total JS execution
REVIEW
1684ms total JS execution
Warning::
https://www.rijksoverheid.nl/: 627ms CPU time
Warning::
https://statistiek.rijksoverheid.nl/containers/bf9...: 294ms CPU time
Warning::
Unattributable: 274ms CPU time
Warning::
https://www.rijksoverheid.nl/webfiles/175001183407...: 259ms CPU time
Info::
https://survey-deploy.platformrijksoverheid.nl/js/...: 102ms CPU time
Warning::
Third-party scripts: 1684ms (100% of total)

Main Thread Breakdown

Script Evaluation 34% Other 29% Style & Layout 22% Script Parsing & Compilation 6% Rendering 6%
ScriptTotalScriptingParse/CompileParty
https://www.rijksoverheid.nl/627ms16ms4ms3rd
https://statistiek.rijksoverheid.nl/containers/bf9c05f0-c13f-4e22-80c7-e603d39fc616.js294ms222ms57ms3rd
Unattributable274ms7ms0ms3rd
https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/core.js259ms170ms19ms3rd
https://survey-deploy.platformrijksoverheid.nl/js/pastease.js102ms64ms7ms3rd
https://statistiek.rijksoverheid.nl/ppms.js67ms55ms9ms3rd
https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/shared-ro/img-helpers.js61ms46ms3ms3rd
B
JS Bundles
7 scripts, 57 KB unused
REVIEW
7 scripts, 57 KB unused
Warning::
https://statistiek.rijksoverheid.nl/containers/bf9...: 36 KB unused (46%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.rijksoverheid.nl/webfiles/175001183407...: 20 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/bf9c05f0-c13f-4e22-80c7-e603d39fc616.js79 KB36 KB (46%)✓3rd
https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/core.js44 KB20 KB (47%)✓3rd
https://www.rijksoverheid.nl/binaries/content/assets/rijksoverheid/behaviour/rop-page-feedback.min-20230526.js3 KB—✓3rd
https://statistiek.rijksoverheid.nl/ppms.js26 KB—✓3rd
https://survey-deploy.platformrijksoverheid.nl/js/pastease.js13 KB—✓3rd
https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/shared-ro/jquery-ui.js11 KB—✓3rd
https://www.rijksoverheid.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
1007 KB transferred, 25 requests
PASS
1007 KB transferred, 25 requests
Info::
Page weighs 1.7 MB (1007 KB transferred)
Info::
Fonts are 260 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 260 KB
Info::
25 HTTP requests
Info::
Estimated 0.21 g CO2 per page load
1007 KB / 2.4 MB budget
1007 KB transferred
25 requests
0.21 g CO2 per page load
Images 503.3 KiB 50%
Fonts 260.2 KiB 26%
JavaScript 181.5 KiB 18%
CSS 50.0 KiB 5%
HTML 8.0 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

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

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+
Font Loading
5 fonts (260 KB)
PASS
5 fonts (260 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

260 KB total

Render-blocking

0

of 5

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 5.0 s 6.0 s 7.0 s 8.0 s 9.0 s FCP 3.7 s LCP 9.4 shttps://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Regular.woff2RO-SansWebText-Regular.... https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Regular.woff2 — 53.6 KiB — 2.5 s — font-display: swaphttps://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/rijks-sans-regular.woff2rijks-sans-regular.woff2 https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/rijks-sans-regular.woff2 — 75.1 KiB — 3.0 s — font-display: swaphttps://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Bold.woff2RO-SansWebText-Bold.woff2 https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Bold.woff2 — 47.9 KiB — 3.0 s — font-display: swaphttps://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/icons/ro-icons-2.4.woff2ro-icons-2.4.woff2 https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/icons/ro-icons-2.4.woff2 — 5.1 KiB — 3.0 s — font-display: swaphttps://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SerifWeb-Italic.woff2RO-SerifWeb-Italic.woff2 https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SerifWeb-Italic.woff2 — 78.5 KiB — 3.9 s — font-display: swap
RO-SansWebText-Regular.... woff2 swap
Size 54 KB
Load time 2.5 s
Start 2.0 s
Risk FOUT — text flashes from fallback to web font
rijks-sans-regular.woff2 woff2 swap
Size 75 KB
Load time 3.0 s
Start 2.0 s
Risk FOUT — text flashes from fallback to web font
RO-SansWebText-Bold.woff2 woff2 swap
Size 48 KB
Load time 3.0 s
Start 2.0 s
Risk FOUT — text flashes from fallback to web font
ro-icons-2.4.woff2 woff2 swap
Size 5 KB
Load time 3.0 s
Start 2.0 s
Risk FOUT — text flashes from fallback to web font
RO-SerifWeb-Italic.woff2 woff2 swap
Size 79 KB
Load time 3.9 s
Start 2.0 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
3 hints, 0 missing preconnects
PASS
3 hints, 0 missing preconnects
Info::
Page uses 3 resource hint(s)

Current Resource Hints

preconnect
—
preload
3
dns-prefetch
—
prefetch
—

3 resource hints configured

A
Page Weight Inventory
25 resources · 1007 KB · 57 KB savings available
PASS
25 resources · 1007 KB · 57 KB savings available
Info::
Within 1MB page-weight target
Got: 1007 KB
Info::
~57 KB of savings available
Warning::
24 third-party resources (100% of weight)
25 resources · 1006.6 KiB · 24 third-party Within 1MB page-weight target
Image 50% · 505.4 KiB
Font 26% · 260.2 KiB
JavaScript 18% · 181.5 KiB
CSS 5% · 50.0 KiB
Document 1% · 8.3 KiB
Other 0% · 1.2 KiB

~56.7 KiB of savings available

Remove unused JavaScript: 56.7 KiB
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
Network Waterfall
25 requests over 6675ms
INFO
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s 8.0 s 9.0 s FCP 3.7 s LCP 9.4 shttps://rijksoverheid.nl// https://rijksoverheid.nl/ — 301 — 304 B — 862 ms — h2https://www.rijksoverheid.nl/www.rijksoverheid.nl/ https://www.rijksoverheid.nl/ — 200 — 8.0 KiB — 399 ms — h2https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/responsive.csswww.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/responsive.css — 200 — 49.2 KiB — 470 ms — h2https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/themes/logoblauw.csswww.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/themes/logoblauw.css — 200 — 754 B — 706 ms — h2https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/core.jswww.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/core.js — 200 — 44.1 KiB — 708 ms — h2https://www.rijksoverheid.nl/binaries/content/gallery/rijksoverheid/channel-afbeeldingen/logos/beeldmerk-rijksoverheid-desktop.svgwww.rijksoverheid.nl/binaries/conte... https://www.rijksoverheid.nl/binaries/content/gallery/rijksoverheid/channel-afbeeldingen/logos/beeldmerk-rijksoverheid-desktop.svg — 200 — 6.5 KiB — 1.4 s — h2https://www.rijksoverheid.nl/binaries/medium/content/gallery/rijksoverheid/content-afbeeldingen/home/2026/energiemaatregelen-anp-556197185.jpgwww.rijksoverheid.nl/binaries/mediu... https://www.rijksoverheid.nl/binaries/medium/content/gallery/rijksoverheid/content-afbeeldingen/home/2026/energiemaatregelen-anp-556197185.jpg — 200 — 117.3 KiB — 1.9 s — h2https://www.rijksoverheid.nl/binaries/medium/content/gallery/rijksoverheid/content-afbeeldingen/onderwerpen/reizen-met-kinderen/reizen-met-kinderen-uitgelicht.jpgwww.rijksoverheid.nl/binaries/mediu... https://www.rijksoverheid.nl/binaries/medium/content/gallery/rijksoverheid/content-afbeeldingen/onderwerpen/reizen-met-kinderen/reizen-met-kinderen-uitgelicht.jpg — 200 — 104.1 KiB — 1.9 s — h2https://www.rijksoverheid.nl/binaries/medium/content/gallery/rijksoverheid/content-afbeeldingen/home/evergreens/uitgelicht-noodpakket.jpgwww.rijksoverheid.nl/binaries/mediu... https://www.rijksoverheid.nl/binaries/medium/content/gallery/rijksoverheid/content-afbeeldingen/home/evergreens/uitgelicht-noodpakket.jpg — 200 — 116.7 KiB — 2.1 s — h2https://www.rijksoverheid.nl/binaries/medium/content/gallery/rijksoverheid/banner-afbeeldingen/onderwerpen/w/woning-huren/woning-huren.jpgwww.rijksoverheid.nl/binaries/mediu... https://www.rijksoverheid.nl/binaries/medium/content/gallery/rijksoverheid/banner-afbeeldingen/onderwerpen/w/woning-huren/woning-huren.jpg — 200 — 158.7 KiB — 3.9 s — h2https://www.rijksoverheid.nl/binaries/content/assets/rijksoverheid/behaviour/rop-page-feedback.min-20230526.jswww.rijksoverheid.nl/binaries/conte... https://www.rijksoverheid.nl/binaries/content/assets/rijksoverheid/behaviour/rop-page-feedback.min-20230526.js — 200 — 2.7 KiB — 3.7 s — h2https://statistiek.rijksoverheid.nl/containers/bf9c05f0-c13f-4e22-80c7-e603d39fc616.jsstatistiek.rijksoverheid.nl/contain... https://statistiek.rijksoverheid.nl/containers/bf9c05f0-c13f-4e22-80c7-e603d39fc616.js — 200 — 79.0 KiB — 973 ms — h2https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Regular.woff2www.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Regular.woff2 — 200 — 53.6 KiB — 2.5 s — h2https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/rijks-sans-regular.woff2www.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/rijks-sans-regular.woff2 — 200 — 75.1 KiB — 3.0 s — h2https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Bold.woff2www.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SansWebText-Bold.woff2 — 200 — 47.9 KiB — 3.0 s — h2https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/icons/ro-icons-2.4.woff2www.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/icons/ro-icons-2.4.woff2 — 200 — 5.1 KiB — 3.0 s — h2https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SerifWeb-Italic.woff2www.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/presentation/shared-ro/webfonts/RO-SerifWeb-Italic.woff2 — 200 — 78.5 KiB — 3.9 s — h2https://statistiek.rijksoverheid.nl/ppms.jsstatistiek.rijksoverheid.nl/ppms.js https://statistiek.rijksoverheid.nl/ppms.js — 200 — 25.9 KiB — 171 ms — h2https://survey-deploy.platformrijksoverheid.nl/js/pastease.jssurvey-deploy.platformrijksoverheid... https://survey-deploy.platformrijksoverheid.nl/js/pastease.js — 200 — 13.5 KiB — 26 ms — h2https://survey-deploy.platformrijksoverheid.nl/config/5qaKbX1sz1G7F8ba3s1LtJ8j6lFnJhFRD7F6LKZHsurvey-deploy.platformrijksoverheid... https://survey-deploy.platformrijksoverheid.nl/config/5qaKbX1sz1G7F8ba3s1LtJ8j6lFnJhFRD7F6LKZH — 200 — 1.2 KiB — 8 ms — h2https://statistiek.rijksoverheid.nl/ppms.phpstatistiek.rijksoverheid.nl/ppms.ph... https://statistiek.rijksoverheid.nl/ppms.php — 202 — 0 B — 168 ms — h2https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/shared-ro/jquery-ui.jswww.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/shared-ro/jquery-ui.js — 200 — 10.9 KiB — 1.2 s — h2https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/shared-ro/img-helpers.jswww.rijksoverheid.nl/webfiles/17500... https://www.rijksoverheid.nl/webfiles/1750011834072/behaviour/shared-ro/img-helpers.js — 200 — 5.5 KiB — 235 ms — h2https://statistiek.rijksoverheid.nl/ppms.phpstatistiek.rijksoverheid.nl/ppms.ph... https://statistiek.rijksoverheid.nl/ppms.php — 202 — 0 B — 167 ms — h2https://www.rijksoverheid.nl/binaries/content/assets/rijksoverheid/iconen/favicon.icowww.rijksoverheid.nl/binaries/conte... https://www.rijksoverheid.nl/binaries/content/assets/rijksoverheid/iconen/favicon.ico — 200 — 2.1 KiB — 235 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 1684ms · 176KB · €18/mo
www.rijksoverheid.nl
Other
Costly
Execution 627ms
Transfer 8 KB
Monthly Cost €7/mo
statistiek.rijksoverheid.nl
Other
Costly
Execution 294ms
Transfer 79 KB
Unused 46%
Monthly Cost €3/mo
Unattributable
Other
Costly
Execution 274ms
Transfer 0 KB
Monthly Cost €3/mo
www.rijksoverheid.nl
Other
Costly
Execution 259ms
Transfer 44 KB
Unused 47%
Monthly Cost €3/mo
survey-deploy.platformrijksoverheid.nl
Other
Optional
Execution 102ms
Transfer 13 KB
Monthly Cost €1/mo
statistiek.rijksoverheid.nl
Other
Optional
Execution 67ms
Transfer 26 KB
Monthly Cost €1/mo
www.rijksoverheid.nl
Other
Optional
Execution 61ms
Transfer 6 KB
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • www.rijksoverheid.nl adds 627ms and costs ~€7/month
  • statistiek.rijksoverheid.nl adds 294ms and costs ~€3/month
  • Unattributable adds 274ms and costs ~€3/month
  • www.rijksoverheid.nl adds 259ms and costs ~€3/month

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

www.rijksoverheid.nl takes 627ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

statistiek.rijksoverheid.nl takes 294ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Unattributable takes 274ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

www.rijksoverheid.nl takes 259ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

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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