Performance

· 22 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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

Mobile Desktop

100

Performance

Accessibility

100

Best Practices

100

SEO

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

503 ms

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

543 ms

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.

0.060

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

631 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.

544 ms

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

12 PASS 5 REVIEW 2 FIX

Third-Party Impact

Action

100% third-party, 0 ms blocking

FIX

100% third-party, 0 ms blocking

Third-party code accounts for 100% of page weight (411.1 KiB of 412.0 KiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

HTTP Caching

Action

No cache headers

FIX

No cache headers

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.

Image Optimization

4 images, 0 KB saveable

REVIEW

4 images, 0 KB saveable

https://www.capfi.fr/assets/images/logo_blanc.webp is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

https://www.capfi.fr/assets/images/logo_Bcorp_blan... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

4 images 278 KB

0 oversized -0 KB

2 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

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Compression Algorithm

Action

Main response served uncompressed

REVIEW

Main response served uncompressed

Main HTML response has no Content-Encoding (uncompressed)

The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.

Main HTML Cache-Control

No Cache-Control header on main HTML response

REVIEW

No Cache-Control header on main HTML response

Main HTML response has no Cache-Control header

Without an explicit Cache-Control, browsers fall back to heuristic caching (~10% of Last-Modified age). Set `Cache-Control: no-cache` or `max-age=300` for HTML to control freshness explicitly -- prevents stale auth state and SPA shell drift.

Server-Timing Observability

No Server-Timing header found

REVIEW

No Server-Timing header found

Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

A+

Page Weight Budget

412 KB transferred, 16 requests

PASS

412 KB transferred, 16 requests

Page weighs 524 KB (412 KB transferred)

16 HTTP requests

Estimated 0.08 g CO2 per page load

412 KB transferred

16 requests

0.08 g CO2 per page load

Images 278.3 KiB 68%

Fonts 60.2 KiB 15%

Other 21.4 KiB 5%

JavaScript 18.8 KiB 5%

CSS 18.1 KiB 4%

HTML 13.5 KiB 3%

Other 1.8 KiB 0%

0 2.4 MB 4.9 MB

Under budget

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

JS Execution Cost

122ms total JS execution

PASS

122ms total JS execution

https://www.capfi.fr/: 122ms CPU time

Third-party scripts: 122ms (100% of total)

Main Thread Breakdown

Style & Layout 51% Other 26% Script Evaluation 14% Rendering 5%

Script	Total	Scripting	Parse/Compile	Party
https://www.capfi.fr/	122ms	1ms	0ms	3rd

A+

Font Loading

3 fonts (60 KB)

PASS

3 fonts (60 KB)

3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

60 KB total

Render-blocking

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

Flexo-Thin.woff2 woff2 swap

Size 19 KB

Load time 56 ms

Start 408 ms

Risk FOUT — text flashes from fallback to web font

Flexo-Bold.woff2 woff2 swap

Size 20 KB

Load time 65 ms

Start 409 ms

Risk FOUT — text flashes from fallback to web font

Flexo-Regular.woff2 woff2 swap

Size 21 KB

Load time 66 ms

Start 409 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)

JS Bundles

4 scripts, 0 KB unused

PASS

4 scripts, 0 KB unused

https://www.capfi.fr/assets/js/dynamic-content.js: unminified — 3 KB could be saved

0 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.capfi.fr/assets/js/main.js	6 KB	—	✓	3rd
https://www.capfi.fr/assets/js/dynamic-content.js	9 KB	—	✗	3rd
https://www.capfi.fr/assets/js/cookie-consent.js	2 KB	—	✓	3rd
https://www.capfi.fr/assets/js/eco-badge.js	2 KB	—	✓	3rd

A+

Resource Caching

All resources properly cached

PASS

All resources properly cached

No caching issues found

All static resources have appropriate caching headers.

A+

Critical Rendering Path

No render-blocking resources

PASS

No render-blocking resources

No render-blocking resources detected

A+

Resource Hints

No optimization needed

PASS

No optimization needed

No resource hint issues

A+

HTTP/3 (QUIC)

HTTP/3 advertised via Alt-Svc

PASS

HTTP/3 advertised via Alt-Svc

HTTP/3 (QUIC) is supported

First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.

A+

LCP Image Preload

LCP preload audit not available

PASS

LCP preload audit not available

LCP image preload audit not available for this scan

A+

Server Response Intelligence

1 server-response signal(s) detected

PASS

1 server-response signal(s) detected

No `ETag` or `Last-Modified` -- conditional GET not supported

Without either header, browsers can't issue conditional GETs and refresh always re-downloads the full response body even when nothing changed. Add `ETag: "<hash>"` (or `Last-Modified: <date>`) on cacheable responses; the server returns 304 Not Modified when the client's cached copy is still valid, saving bandwidth.

Page Weight Inventory

16 resources · 412 KB · 0 KB savings available

PASS

16 resources · 412 KB · 0 KB savings available

Within 1MB page-weight target

Got: 412 KB

15 third-party resources (100% of weight)

1 resources over 200KB

16 resources · 412.0 KiB · 15 third-party Within 1MB page-weight target

Image 73% · 298.7 KiB

Font 15% · 60.2 KiB

JavaScript 5% · 18.8 KiB

CSS 4% · 18.1 KiB

Document 4% · 14.5 KiB

Other 0% · 1.8 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

16 resources			412.0 KiB

Network Waterfall

16 requests over 1808ms

INFO

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 122ms · 14KB · €2/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
www.capfi.fr www.capfi.fr	Other	122ms	14 KB	—	€2/mo	Optional

www.capfi.fr

Other

Optional

Execution 122ms

Transfer 14 KB

Monthly Cost €2/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

Image Optimization

12 images, 20 KB total, 6 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

20 KB

Oversized

Wasted

6 KB

5 missing dimensions 1 missing lazy loading

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.