Performance
· 15 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.
525 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.41 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.
0.043
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.07 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.
2.47 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 sFPage Weight BudgetAction3.1 MB transferred, 125 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
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
CImage OptimizationAction20 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
CPage Weight InventoryAction125 resources · 3.1 MB · 29 KB savings availableREVIEW
~29.4 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 125 resources | 3.1 MiB | ||||||
A+Third-Party Impact1% third-party, 0 ms blockingPASS
A+Text CompressionAll text resources are compressedPASS
A+JS Execution Cost342ms total JS executionPASS
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://cnil.fr/fr | 198ms | 5ms | 1ms | 1st |
| Unattributable | 145ms | 2ms | 0ms | 3rd |
A+Font Loading8 fonts (196 KB)PASS
Web fonts
8
196 KB total
Render-blocking
0
of 8
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
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)
Fixing the unchecked items could save ~1 KB and ~2 ms
AJS Bundles59 scripts, 29 KB unusedPASS
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://cnil.fr/modules/contrib/tacjs/assets/vendor/tarteaucitron.js/tarteaucitron.services.js?v=1.20.0 | 40 KB | 29 KB (73%) | ✗ | 1st |
| https://piwik.cnil.fr/matomo.js | 20 KB | — | ✓ | 3rd |
| https://cnil.fr/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 | 30 KB | — | ✓ | 1st |
| https://cnil.fr/core/assets/vendor/underscore/underscore-min.js?v=1.13.7 | 8 KB | — | ✓ | 1st |
| https://cnil.fr/core/assets/vendor/once/once.min.js?v=1.0.1 | 1 KB | — | ✓ | 1st |
| https://cnil.fr/sites/default/files/languages/fr_Ol6GqvZbhE2emJ9M9avhr_o8QlfsgRPhWCjQbYqzplc.js?tboeb7 | 7 KB | — | ✓ | 1st |
| https://cnil.fr/core/misc/drupalSettingsLoader.js?v=10.5.6 | 1 KB | — | ✓ | 1st |
| https://cnil.fr/core/misc/drupal.js?v=10.5.6 | 6 KB | — | ✗ | 1st |
| https://cnil.fr/core/misc/drupal.init.js?v=10.5.6 | 1 KB | — | ✓ | 1st |
| https://cnil.fr/themes/contrib/bootstrap/js/bootstrap-pre-init.js?tboeb7 | 0 KB | — | ✓ | 1st |
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
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
A+HTTP Cachingmax-age=31536000 (52 weeks)PASS
max-age=31536000, public
| Directive | Value | Meaning |
|---|---|---|
| max-age | 31536000 | Cache for 52 weeks |
| public | — | Any cache may store this response |
Network Waterfall125 requests over 1162msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 145ms | 0 KB | — | €2/mo | Optional |
42% of JavaScript execution time comes from third-party scripts.
Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.
Learn more ▾ ▴
Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.
Source: web.dev / HTTP Archive Web Almanac