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https://www.education.gouv.fr

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
85
GRADE
B
FIX
2
REVIEW
3
PASS
9
INFO
2

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

Mobile Desktop
66
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.
81
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.

3.57 s

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

5.56 s

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

210 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.

5.02 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.

5.59 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
16
9 PASS 3 REVIEW 2 FIX
D
JS Execution Cost
Action
2504ms total JS execution
FIX
2504ms total JS execution
Warning::
https://www.education.gouv.fr/libraries/dsfr/dist/...: 619ms CPU time
Warning::
https://www.education.gouv.fr/: 601ms CPU time
Warning::
Unattributable: 594ms CPU time
Warning::
https://www.education.gouv.fr/cdn-cgi/challenge-pl...: 363ms CPU time
Info::
https://www.education.gouv.fr/sites/default/files/...: 137ms CPU time
Info::
Third-party scripts: 594ms (24% of total)

Main Thread Breakdown

Other 35% Script Evaluation 34% Style & Layout 23% Parse HTML & CSS 4%
ScriptTotalScriptingParse/CompileParty
https://www.education.gouv.fr/libraries/dsfr/dist/dsfr.module.js?v=1.x619ms247ms1ms1st
https://www.education.gouv.fr/601ms82ms2ms1st
Unattributable594ms6ms0ms3rd
https://www.education.gouv.fr/cdn-cgi/challenge-platform/scripts/jsd/main.js363ms349ms2ms1st
https://www.education.gouv.fr/sites/default/files/js/js_tzoLcjdeSzPZwn63KF-tyOCA_bDWuZUo80sYsW6aoT8.js?scope=footer&delta=2&language=fr&theme=edugouv_dsfr&include=eJxVjOEKAyEMg1_oPB9JPO1KobZi68C3H9vY8P6E5EtI0QGxaOsqIG6nZ6nQUrXHCMGJIeHQ2Q-oE3U-P0Us01zbsW3jWxIJ-Y0i65U5mC8mwV-FtY-4-Z2nLJmXU7Hv5T--ABorQts137ms75ms21ms1st
https://www.education.gouv.fr/sites/default/files/js/js_WfPPp7sH-1ECmhNZVUIC56qjeFlH4GbDtBfWjYg9VPI.js?scope=footer&delta=0&language=fr&theme=edugouv_dsfr&include=eJxVjOEKAyEMg1_oPB9JPO1KobZi68C3H9vY8P6E5EtI0QGxaOsqIG6nZ6nQUrXHCMGJIeHQ2Q-oE3U-P0Us01zbsW3jWxIJ-Y0i65U5mC8mwV-FtY-4-Z2nLJmXU7Hv5T--ABorQts107ms68ms9ms1st
https://www.education.gouv.fr/core/assets/vendor/modernizr/modernizr.min.js?v=3.11.782ms26ms2ms1st
D
HTTP Caching
Action
no-store (uncacheable)
FIX
no-store (uncacheable)
Info::
Cache-Control: no-store prevents all caching
Intentional for dynamic content, but increases server load for every page view.
Got: private, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

private, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0

DirectiveValueMeaning
private—Only browser cache, not CDN/proxy
max-age0Cache for 0 seconds
no-store—Never cache this response
no-cache—Cache but always revalidate first
must-revalidate—Must recheck with server after expiry
post-check0
pre-check0
C
Page Weight Budget
Action
1.9 MB transferred, 49 requests
REVIEW
1.9 MB transferred, 49 requests
Info::
Page weighs 3.8 MB (1.9 MB transferred)
Warning::
Images are 1.4 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.4 MB
Info::
49 HTTP requests
Info::
Estimated 0.40 g CO2 per page load
1.9 MB / 2.4 MB budget
1.9 MB transferred
49 requests
0.40 g CO2 per page load
Images 1.4 MiB 72%
JavaScript 213.1 KiB 11%
Fonts 166.2 KiB 9%
CSS 151.7 KiB 8%
HTML 16.1 KiB 1%
Other 3.0 KiB 0%
Other 757 B 0%
Other 451 B 0%
0 2.4 MB 4.9 MB
Approaching limit

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

C
Image Optimization
Action
25 images, 0 KB saveable
REVIEW
25 images, 0 KB saveable
Warning::
https://www.education.gouv.fr/sites/default/files/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
25 images 1.4 MB
0 oversized -0 KB
15 legacy format
2 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

Performance issues directly impact user engagement and conversion rates.

C
JS Bundles
Action
10 scripts, 75 KB unused
REVIEW
10 scripts, 75 KB unused
Warning::
https://www.education.gouv.fr/sites/default/files/...: 30 KB unused (61%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.education.gouv.fr/libraries/tarteaucit...: 24 KB unused (73%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.education.gouv.fr/libraries/tarteaucit...: unminified — 9 KB could be saved
Warning::
https://www.education.gouv.fr/sites/default/files/...: 22 KB unused (57%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.education.gouv.fr/libraries/dsfr/dist/...: unminified — 8 KB could be saved
Info::
Total unused JavaScript: 75 KB
75 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.education.gouv.fr/sites/default/files/js/js_tzoLcjdeSzPZwn63KF-tyOCA_bDWuZUo80sYsW6aoT8.js?scope=footer&delta=2&language=fr&theme=edugouv_dsfr&include=eJxVjOEKAyEMg1_oPB9JPO1KobZi68C3H9vY8P6E5EtI0QGxaOsqIG6nZ6nQUrXHCMGJIeHQ2Q-oE3U-P0Us01zbsW3jWxIJ-Y0i65U5mC8mwV-FtY-4-Z2nLJmXU7Hv5T--ABorQts49 KB30 KB (61%)✓1st
https://www.education.gouv.fr/libraries/tarteaucitron.js/tarteaucitron.services.js?v=2022032233 KB24 KB (73%)✗1st
https://www.education.gouv.fr/sites/default/files/js/js_WfPPp7sH-1ECmhNZVUIC56qjeFlH4GbDtBfWjYg9VPI.js?scope=footer&delta=0&language=fr&theme=edugouv_dsfr&include=eJxVjOEKAyEMg1_oPB9JPO1KobZi68C3H9vY8P6E5EtI0QGxaOsqIG6nZ6nQUrXHCMGJIeHQ2Q-oE3U-P0Us01zbsW3jWxIJ-Y0i65U5mC8mwV-FtY-4-Z2nLJmXU7Hv5T--ABorQts39 KB22 KB (57%)✓1st
https://www.education.gouv.fr/core/assets/vendor/modernizr/modernizr.min.js?v=3.11.73 KB—✓1st
https://www.education.gouv.fr/libraries/dsfr/dist/dsfr.module.js?v=1.x37 KB—✗1st
https://www.education.gouv.fr/libraries/dsfr/dist/analytics/analytics.module.js?td4vez22 KB—✗1st
https://www.education.gouv.fr/libraries/tarteaucitron.js/lang/tarteaucitron.fr.js?v=202203221 KB—✓1st
https://www.education.gouv.fr/cdn-cgi/challenge-platform/h/b/scripts/jsd/625261456364/main.js?12 KB—✓1st
https://wrhv.education.gouv.fr/fuF559.js?214 KB—✓3rd
https://wrhv.education.gouv.fr/col571a/-/93090749?ss=412x823&url=https%3A%2F%2Fwww.education.gouv.fr%2F&sd=24&evariant=2-4&fra=0&3 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

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+
Third-Party Impact
1% third-party, 0 ms blocking
PASS
1% third-party, 0 ms blocking
Info::
Third-party code accounts for 1% of page weight (18.1 KiB of 1.9 MiB)
Info::
Third-party blocking time is low (0 ms)
99%
First-party Third-party
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
4 fonts (166 KB)
PASS
4 fonts (166 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

166 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 5.0 s FCP 3.6 s LCP 5.6 shttps://www.education.gouv.fr/libraries/dsfr/dist/fonts/Marianne-Regular.woff2Marianne-Regular.woff2 https://www.education.gouv.fr/libraries/dsfr/dist/fonts/Marianne-Regular.woff2 — 40.5 KiB — 0 ms — font-display: swaphttps://www.education.gouv.fr/libraries/dsfr/dist/fonts/Marianne-Bold.woff2Marianne-Bold.woff2 https://www.education.gouv.fr/libraries/dsfr/dist/fonts/Marianne-Bold.woff2 — 41.2 KiB — 0 ms — font-display: swaphttps://www.education.gouv.fr/libraries/dsfr/dist/fonts/Marianne-Medium.woff2Marianne-Medium.woff2 https://www.education.gouv.fr/libraries/dsfr/dist/fonts/Marianne-Medium.woff2 — 41.1 KiB — 0 ms — font-display: swaphttps://www.education.gouv.fr/libraries/dsfr/dist/fonts/Marianne-Regular_Italic.woff2Marianne-Regular_Italic... https://www.education.gouv.fr/libraries/dsfr/dist/fonts/Marianne-Regular_Italic.woff2 — 43.4 KiB — 0 ms — font-display: swap
Marianne-Regular.woff2 woff2 swap
Size 41 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Marianne-Bold.woff2 woff2 swap
Size 41 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Marianne-Medium.woff2 woff2 swap
Size 41 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Marianne-Regular_Italic... woff2 swap
Size 43 KB
Load time 0 ms
Start 0 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+
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+
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
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
49 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
24% of JavaScript execution is third-party
First-party Third-party 594ms · 0KB · €6/mo
Unattributable
Other
Costly
Execution 594ms
Transfer 0 KB
Monthly Cost €6/mo

These scripts may cost more than they're worth

  • Unattributable adds 594ms and costs ~€6/month

Unattributable takes 594ms 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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