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https://matheo-olsen.fr

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
94
GRADE
A
FIX
2
REVIEW
0
PASS
12
INFO
2

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

Mobile Desktop
80
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
97
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
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.

3.15 s

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

3.70 s

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

162 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.

4.29 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.

5.48 s

Page Load Progression

649 ms
1.3 s
1.9 s
2.6 s
3.2 s
3.9 s
4.5 s
5.2 s
Checks
16
12 PASS 2 FIX
D
JS Execution Cost
Action
2628ms total JS execution
FIX
2628ms total JS execution
Warning::
https://matheo-olsen.fr/_next/static/chunks/8f02d1...: 1016ms CPU time
Warning::
https://matheo-olsen.fr/: 864ms CPU time
Warning::
Unattributable: 481ms CPU time
Info::
https://matheo-olsen.fr/_next/static/chunks/5cf263...: 186ms CPU time
Info::
https://matheo-olsen.fr/_next/static/chunks/fcb71b...: 80ms CPU time
Info::
Third-party scripts: 481ms (18% of total)

Main Thread Breakdown

Script Evaluation 38% Other 36% Style & Layout 13% Script Parsing & Compilation 6% Rendering 5%
ScriptTotalScriptingParse/CompileParty
https://matheo-olsen.fr/_next/static/chunks/8f02d17ed0289fd9.js1016ms842ms28ms1st
https://matheo-olsen.fr/864ms21ms40ms1st
Unattributable481ms22ms0ms3rd
https://matheo-olsen.fr/_next/static/chunks/5cf263598dde299a.js186ms71ms20ms1st
https://matheo-olsen.fr/_next/static/chunks/fcb71b7647f4ee33.js80ms49ms24ms1st
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, no-cache, no-store, max-age=0, must-revalidate
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

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

DirectiveValueMeaning
private—Only browser cache, not CDN/proxy
no-cache—Cache but always revalidate first
no-store—Never cache this response
max-age0Cache for 0 seconds
must-revalidate—Must recheck with server after expiry
A+
Page Weight Budget
652 KB transferred, 37 requests
PASS
652 KB transferred, 37 requests
Info::
Page weighs 1.5 MB (652 KB transferred)
Info::
37 HTTP requests
Info::
Estimated 0.13 g CO2 per page load
652 KB / 2.4 MB budget
652 KB transferred
37 requests
0.13 g CO2 per page load
JavaScript 236.0 KiB 36%
Fonts 190.4 KiB 29%
Images 119.8 KiB 18%
HTML 65.9 KiB 10%
CSS 18.9 KiB 3%
Other 15.2 KiB 2%
Other 5.8 KiB 1%
Other 0 B 0%
0 2.4 MB 4.9 MB
Under budget
A+
Third-Party Impact
0% third-party, 0 ms blocking
PASS
0% third-party, 0 ms blocking
Info::
Third-party code accounts for 0% of page weight (2.5 KiB of 652.1 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
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+
Image Optimization
5 images, 0 KB saveable
PASS
5 images, 0 KB saveable
Info::
All images are well-optimized
5 images 120 KB
0 oversized -0 KB
0 legacy format
0 missing dimensions CLS risk
A+
Font Loading
6 fonts (190 KB)
PASS
6 fonts (190 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

190 KB total

Render-blocking

0

of 6

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 FCP 3.2 s LCP 3.7 shttps://matheo-olsen.fr/_next/static/media/70bc3e132a0a741e-s.p.15008bfb.woff270bc3e132a0a741e-s.p.15... https://matheo-olsen.fr/_next/static/media/70bc3e132a0a741e-s.p.15008bfb.woff2 — 39.6 KiB — 0 ms — font-display: swaphttps://matheo-olsen.fr/_next/static/media/83afe278b6a6bb3c-s.p.3a6ba036.woff283afe278b6a6bb3c-s.p.3a... https://matheo-olsen.fr/_next/static/media/83afe278b6a6bb3c-s.p.3a6ba036.woff2 — 47.5 KiB — 0 ms — font-display: swaphttps://matheo-olsen.fr/_next/static/media/Satoshi_Black-s.p.e6332f7c.woff2Satoshi_Black-s.p.e6332... https://matheo-olsen.fr/_next/static/media/Satoshi_Black-s.p.e6332f7c.woff2 — 23.8 KiB — 0 ms — font-display: swaphttps://matheo-olsen.fr/_next/static/media/Satoshi_Bold-s.p.112e30eb.woff2Satoshi_Bold-s.p.112e30... https://matheo-olsen.fr/_next/static/media/Satoshi_Bold-s.p.112e30eb.woff2 — 26.2 KiB — 0 ms — font-display: swaphttps://matheo-olsen.fr/_next/static/media/Satoshi_Medium-s.p.1733cd2d.woff2Satoshi_Medium-s.p.1733... https://matheo-olsen.fr/_next/static/media/Satoshi_Medium-s.p.1733cd2d.woff2 — 26.7 KiB — 0 ms — font-display: swaphttps://matheo-olsen.fr/_next/static/media/Satoshi_Regular-s.p.9e077bec.woff2Satoshi_Regular-s.p.9e0... https://matheo-olsen.fr/_next/static/media/Satoshi_Regular-s.p.9e077bec.woff2 — 26.6 KiB — 0 ms — font-display: swap
70bc3e132a0a741e-s.p.15... woff2 swap
Size 40 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
83afe278b6a6bb3c-s.p.3a... woff2 swap
Size 47 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Satoshi_Black-s.p.e6332... woff2 swap
Size 24 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Satoshi_Bold-s.p.112e30... woff2 swap
Size 26 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Satoshi_Medium-s.p.1733... woff2 swap
Size 27 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Satoshi_Regular-s.p.9e0... woff2 swap
Size 27 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+
JS Bundles
14 scripts, 46 KB unused
PASS
14 scripts, 46 KB unused
Warning::
https://matheo-olsen.fr/_next/static/chunks/8f02d1...: 24 KB unused (35%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://matheo-olsen.fr/_next/static/chunks/5cf263...: 22 KB unused (43%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 46 KB
46 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://matheo-olsen.fr/_next/static/chunks/8f02d17ed0289fd9.js68 KB24 KB (35%)✓1st
https://matheo-olsen.fr/_next/static/chunks/5cf263598dde299a.js51 KB22 KB (43%)✓1st
https://matheo-olsen.fr/_next/static/chunks/d2be314c3ece3fbe.js7 KB—✓1st
https://matheo-olsen.fr/_next/static/chunks/fcb71b7647f4ee33.js31 KB—✓1st
https://matheo-olsen.fr/_next/static/chunks/turbopack-bd0d8e0b93f19072.js4 KB—✓1st
https://matheo-olsen.fr/_next/static/chunks/ff1a16fafef87110.js0 KB—✓1st
https://matheo-olsen.fr/_next/static/chunks/88ce5e0501235404.js8 KB—✓1st
https://matheo-olsen.fr/_next/static/chunks/65939ba4da6e334d.js10 KB—✓1st
https://matheo-olsen.fr/_next/static/chunks/f091501564eb2ea3.js7 KB—✓1st
https://matheo-olsen.fr/_next/static/chunks/d3b4408da246cf8e.js11 KB—✓1st

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+
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
8 hints, 0 missing preconnects
PASS
8 hints, 0 missing preconnects
Info::
Page uses 8 resource hint(s)

Current Resource Hints

preconnect
—
preload
8
dns-prefetch
—
prefetch
—

8 resource hints configured

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: OVHcloud

Network Waterfall
37 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
18% of JavaScript execution is third-party
First-party Third-party 481ms · 0KB · €5/mo
Unattributable
Other
Costly
Execution 481ms
Transfer 0 KB
Monthly Cost €5/mo

These scripts may cost more than they're worth

  • Unattributable adds 481ms and costs ~€5/month

Unattributable takes 481ms 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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