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.
574 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.77 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
20 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.096
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
926 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.
1.78 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 sDThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BPage Weight Budget1.3 MB transferred, 48 requestsREVIEW
Subset fonts to include only used characters, or switch to system font stacks.
Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).
Source: web.dev font loading
BJS Execution Cost564ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.senat.fr/ | 246ms | 10ms | 1ms | 3rd |
| https://www.senat.fr/_assets/cru-1776709016/eee83a27e1e6e241ed7098a5f815474c/Frontend/assets/scripts/senat.js?1775688233 | 141ms | 88ms | 4ms | 3rd |
| Unattributable | 117ms | 6ms | 0ms | 3rd |
| https://www.senat.fr/_assets/cru-1776709016/eee83a27e1e6e241ed7098a5f815474c/Frontend/assets/scripts/vendor.js?1775688233 | 60ms | 12ms | 24ms | 3rd |
BJS Bundles4 scripts, 122 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.senat.fr/_assets/cru-1776709016/eee83a27e1e6e241ed7098a5f815474c/Frontend/assets/scripts/vendor.js?1775688233 | 122 KB | 84 KB (69%) | ✓ | 3rd |
| https://stats.integra.fr/matomo.js | 66 KB | 39 KB (59%) | ✓ | 3rd |
| https://www.senat.fr/_assets/cru-1776709016/eee83a27e1e6e241ed7098a5f815474c/Frontend/assets/scripts/manifest.js?1775688233 | 1 KB | — | ✓ | 3rd |
| https://www.senat.fr/_assets/cru-1776709016/eee83a27e1e6e241ed7098a5f815474c/Frontend/assets/scripts/senat.js?1775688233 | 19 KB | — | ✓ | 3rd |
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
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
CPage Weight InventoryAction48 resources · 1.3 MB · 122 KB savings availableREVIEW
~122.4 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 48 resources | 1.3 MiB | ||||||
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
AImage Optimization24 images, 0 KB saveablePASS
A+Font Loading10 fonts (704 KB)PASS
Web fonts
10
704 KB total
Render-blocking
0
of 10
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~66 KB and ~132 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall48 requests over 940msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.senat.fr www.senat.fr | Other | 246ms | 29 KB | — | €3/mo | Costly |
www.senat.fr www.senat.fr | Other | 141ms | 19 KB | — | €2/mo | Optional |
Unattributable Unattributable | Other | 117ms | 0 KB | — | €1/mo | Optional |
www.senat.fr www.senat.fr | Other | 60ms | 122 KB | 69% | €1/mo | Optional |
These scripts may cost more than they're worth
- www.senat.fr adds 246ms and costs ~€3/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
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.senat.fr takes 246ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
69% of www.senat.fr's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev