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Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
88
GRADE
B
FIX
2
REVIEW
2
PASS
9
INFO
2

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

Mobile Desktop
97
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
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.

678 ms

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

1.26 s

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

0 ms

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

0.051

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

678 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

1.26 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
15
9 PASS 2 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 (601.1 KiB of 601.3 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
12 images, 0 KB saveable
REVIEW
12 images, 0 KB saveable
Warning::
https://cdn.public.lu/pictures/logos/gov/fr/2026/g... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://etat.public.lu/fr/_jcr_content/root/root-r... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://etat.public.lu/fr/_jcr_content/root/root-r... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://etat.public.lu/dam-assets/ctie/logo-etat.p... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://etat.public.lu/fr/_jcr_content/root/root-r... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://etat.public.lu/fr/_jcr_content/root/root-r... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cdn.public.lu/pictures/logos/renow.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://etat.public.lu/fr/_jcr_content/root/root-r... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://etat.public.lu/fr/_jcr_content/root/root-r... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://etat.public.lu/fr/_jcr_content/root/root-r... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
12 images 379 KB
0 oversized -0 KB
12 legacy format
10 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

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

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

Green Hosting

No green hosting detected

A+
Page Weight Budget
601 KB transferred, 28 requests
PASS
601 KB transferred, 28 requests
Info::
Page weighs 1018 KB (601 KB transferred)
Info::
28 HTTP requests
Info::
Estimated 0.12 g CO2 per page load
601 KB / 2.4 MB budget
601 KB transferred
28 requests
0.12 g CO2 per page load
Images 378.5 KiB 63%
JavaScript 100.7 KiB 17%
Fonts 53.2 KiB 9%
Other 29.1 KiB 5%
CSS 22.3 KiB 4%
HTML 16.8 KiB 3%
Other 787 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
215ms total JS execution
PASS
215ms total JS execution
Info::
https://etat.public.lu/fr.html: 148ms CPU time
Info::
Unattributable: 67ms CPU time
Warning::
Third-party scripts: 215ms (100% of total)

Main Thread Breakdown

Style & Layout 31% Script Evaluation 26% Other 26% Rendering 8% Parse HTML & CSS 5% Script Parsing & Compilation 4%
ScriptTotalScriptingParse/CompileParty
https://etat.public.lu/fr.html148ms3ms1ms3rd
Unattributable67ms2ms0ms3rd
A+
Font Loading
3 fonts (53 KB)
PASS
3 fonts (53 KB)
Info::
3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

3

53 KB total

Render-blocking

0

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 678 ms LCP 1.3 shttps://cdn.public.lu/fonts/open-sans/open-sans-n7.woff2open-sans-n7.woff2 https://cdn.public.lu/fonts/open-sans/open-sans-n7.woff2 — 18.5 KiB — 84 ms — font-display: swaphttps://cdn.public.lu/fonts/josefinsans/josefinsans-n3.woff2josefinsans-n3.woff2 https://cdn.public.lu/fonts/josefinsans/josefinsans-n3.woff2 — 16.9 KiB — 79 ms — font-display: swaphttps://cdn.public.lu/fonts/open-sans/open-sans-n4.woff2open-sans-n4.woff2 https://cdn.public.lu/fonts/open-sans/open-sans-n4.woff2 — 17.8 KiB — 84 ms — font-display: swap
open-sans-n7.woff2 woff2 swap
Size 18 KB
Load time 84 ms
Start 333 ms
Risk FOUT — text flashes from fallback to web font
josefinsans-n3.woff2 woff2 swap
Size 17 KB
Load time 79 ms
Start 334 ms
Risk FOUT — text flashes from fallback to web font
open-sans-n4.woff2 woff2 swap
Size 18 KB
Load time 84 ms
Start 336 ms
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+
JS Bundles
4 scripts, 25 KB unused
PASS
4 scripts, 25 KB unused
Warning::
https://etat.public.lu/etc.clientlibs/etat/clientl...: 25 KB unused (57%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 25 KB
25 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dependencies.js44 KB25 KB (57%)✓3rd
https://cdn.public.lu/dam-assets/ctie/orejime/v1/js/main.js47 KB—✓3rd
https://etat.public.lu/etc.clientlibs/etat/clientlibs/base.js7 KB—✓3rd
https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dynamic-modules/resources/cmp-image/js/cmp-image.js3 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

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
28 resources · 601 KB · 25 KB savings available
PASS
28 resources · 601 KB · 25 KB savings available
Info::
Within 1MB page-weight target
Got: 601 KB
Warning::
27 third-party resources (100% of weight)
28 resources · 601.3 KiB · 27 third-party Within 1MB page-weight target
Image 68% · 407.1 KiB
JavaScript 17% · 100.7 KiB
Font 9% · 53.2 KiB
CSS 4% · 22.3 KiB
Document 3% · 17.3 KiB
Other 0% · 787 B

~25.0 KiB of savings available

Remove unused JavaScript: 25.0 KiB
Network Waterfall
28 requests over 557ms
INFO
0 ms 500 ms 1.0 s FCP 678 ms LCP 1.3 shttps://public.lu// https://public.lu/ — 302 — 247 B — 58 ms — http/1.1https://etat.public.lu/etat.public.lu/ https://etat.public.lu/ — 302 — 240 B — 78 ms — http/1.1https://etat.public.lu/fr.htmletat.public.lu/fr.html https://etat.public.lu/fr.html — 200 — 16.8 KiB — 40 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dependencies.cssetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dependencies.css — 200 — 228 B — 21 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/base.cssetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/base.css — 200 — 21.4 KiB — 46 ms — http/1.1https://cdn.public.lu/pictures/logos/gov/fr/2026/gov-light.svgcdn.public.lu/pictures/logos/gov/fr... https://cdn.public.lu/pictures/logos/gov/fr/2026/gov-light.svg — 200 — 21.0 KiB — 97 ms — http/1.1https://etat.public.lu/dam-assets/ctie/logo-etat.pngetat.public.lu/dam-assets/ctie/logo... https://etat.public.lu/dam-assets/ctie/logo-etat.png — 200 — 8.3 KiB — 50 ms — http/1.1https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section/col1/image.coreimg.png/1687246919867/luxchat-gov.pngetat.public.lu/fr/_jcr_content/root... https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section/col1/image.coreimg.png/1687246919867/luxchat-gov.png — 200 — 68.4 KiB — 65 ms — http/1.1https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_1985543687/col1/image.coreimg.png/1716900441137/socsol-1.pngetat.public.lu/fr/_jcr_content/root... https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_1985543687/col1/image.coreimg.png/1716900441137/socsol-1.png — 200 — 25.8 KiB — 65 ms — http/1.1https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_1985543687/col2/image_copy.coreimg.png/1716900417486/solvit-etat-lu.pngetat.public.lu/fr/_jcr_content/root... https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_1985543687/col2/image_copy.coreimg.png/1716900417486/solvit-etat-lu.png — 200 — 55.1 KiB — 66 ms — http/1.1https://cdn.public.lu/dam-assets/ctie/orejime/v1/js/main.jscdn.public.lu/dam-assets/ctie/oreji... https://cdn.public.lu/dam-assets/ctie/orejime/v1/js/main.js — 200 — 46.8 KiB — 180 ms — http/1.1https://cdn.public.lu/pictures/logos/renow.pngcdn.public.lu/pictures/logos/renow.... https://cdn.public.lu/pictures/logos/renow.png — 200 — 3.6 KiB — 67 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dependencies.jsetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dependencies.js — 200 — 44.1 KiB — 64 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/base.jsetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/base.js — 200 — 7.0 KiB — 22 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/base/resources/images/favicons/site.webmanifestetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/base/resources/images/favicons/site.webmanifest — 200 — 787 B — 54 ms — http/1.1https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_1985543687/col3/image_copy.coreimg.png/1716900430656/stat-etat-01.pngetat.public.lu/fr/_jcr_content/root... https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_1985543687/col3/image_copy.coreimg.png/1716900430656/stat-etat-01.png — 200 — 59.7 KiB — 41 ms — http/1.1https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_916310751/col1/imagetext/image.coreimg.png/1706265511313/logo-gouv.pngetat.public.lu/fr/_jcr_content/root... https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_916310751/col1/imagetext/image.coreimg.png/1706265511313/logo-gouv.png — 200 — 7.8 KiB — 30 ms — http/1.1https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_916310751/col2/imagetext/image.coreimg.png/1706265523026/logo-guichet.pngetat.public.lu/fr/_jcr_content/root... https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_916310751/col2/imagetext/image.coreimg.png/1706265523026/logo-guichet.png — 200 — 9.1 KiB — 29 ms — http/1.1https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_916310751/col3/imagetext/image.coreimg.png/1716900728045/luxembourg.pngetat.public.lu/fr/_jcr_content/root... https://etat.public.lu/fr/_jcr_content/root/root-responsivegrid/content-responsivegrid/sections-responsivegrid/section_916310751/col3/imagetext/image.coreimg.png/1716900728045/luxembourg.png — 200 — 7.6 KiB — 27 ms — http/1.1https://etat.public.lu/content/dam/etat/ctie/banner.pngetat.public.lu/content/dam/etat/cti... https://etat.public.lu/content/dam/etat/ctie/banner.png — 200 — 101.4 KiB — 30 ms — http/1.1https://etat.public.lu/content/dam/etat/ctie/footer.pngetat.public.lu/content/dam/etat/cti... https://etat.public.lu/content/dam/etat/ctie/footer.png — 200 — 10.7 KiB — 20 ms — http/1.1https://cdn.public.lu/fonts/open-sans/open-sans-n7.woff2cdn.public.lu/fonts/open-sans/open-... https://cdn.public.lu/fonts/open-sans/open-sans-n7.woff2 — 200 — 18.5 KiB — 84 ms — http/1.1https://cdn.public.lu/fonts/josefinsans/josefinsans-n3.woff2cdn.public.lu/fonts/josefinsans/jos... https://cdn.public.lu/fonts/josefinsans/josefinsans-n3.woff2 — 200 — 16.9 KiB — 79 ms — http/1.1https://cdn.public.lu/fonts/open-sans/open-sans-n4.woff2cdn.public.lu/fonts/open-sans/open-... https://cdn.public.lu/fonts/open-sans/open-sans-n4.woff2 — 200 — 17.8 KiB — 84 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dynamic-modules/resources/cmp-image/css/cmp-image.cssetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dynamic-modules/resources/cmp-image/css/cmp-image.css — 200 — 630 B — 19 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dynamic-modules/resources/cmp-image/js/cmp-image.jsetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/clientlib-dynamic-modules/resources/cmp-image/js/cmp-image.js — 200 — 2.9 KiB — 21 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/base/resources/images/favicons/android-chrome-192x192.pngetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/base/resources/images/favicons/android-chrome-192x192.png — 200 — 14.3 KiB — 22 ms — http/1.1https://etat.public.lu/etc.clientlibs/etat/clientlibs/base/resources/images/favicons/android-chrome-192x192.pngetat.public.lu/etc.clientlibs/etat/... https://etat.public.lu/etc.clientlibs/etat/clientlibs/base/resources/images/favicons/android-chrome-192x192.png — 200 — 14.3 KiB — 39 ms — http/1.1
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 215ms · 17KB · €2/mo
etat.public.lu
Other
Optional
Execution 148ms
Transfer 17 KB
Monthly Cost €2/mo
Unattributable
Other
Optional
Execution 67ms
Transfer 0 KB
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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