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https://linuxfr.org

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
85
GRADE
B
FIX
0
REVIEW
5
PASS
7
INFO
3

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

Mobile Desktop
96
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
91
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.

851 ms

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

851 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.

0.038

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

1.73 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.

851 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
15
7 PASS 5 REVIEW
B
Third-Party Impact
41% third-party, 0 ms blocking
REVIEW
41% third-party, 0 ms blocking
Info::
Third-party code accounts for 41% of page weight (429.8 KiB of 1.0 MiB)
Info::
Third-party blocking time is low (0 ms)
59%
41%
First-party Third-party
C
Image Optimization
Action
19 images, 0 KB saveable
REVIEW
19 images, 0 KB saveable
Warning::
https://linuxfr.org/images/sections/62.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/sections/9.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://img.linuxfr.org/img/68747470733a2f2f777777... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/logos/ayo-linuxfr_rentr... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/sections/22.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/sections/50.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://img.linuxfr.org/img/68747470733a2f2f777777... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/sections/85.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://img.linuxfr.org/img/68747470733a2f2f706963... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/sections/79.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/sections/46.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/sections/16.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://linuxfr.org/images/sections/67.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://img.linuxfr.org/img/68747470733a2f2f636f6c... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
19 images 516 KB
0 oversized -0 KB
18 legacy format
14 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

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

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

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

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

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

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

B
JS Bundles
1 scripts, 98 KB unused
REVIEW
1 scripts, 98 KB unused
Warning::
https://linuxfr.org/assets/application-ea18d32113d...: 98 KB unused (69%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 98 KB
98 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://linuxfr.org/assets/application-ea18d32113d34928f73c40c3e7e4aee7b5cc739bee5f9f08fb03d30b00343c90.js144 KB98 KB (69%)✓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

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
max-age=0, private, must-revalidate
REVIEW
max-age=0, private, must-revalidate
Info::
Cache-Control header is set
Got: max-age=0, private, must-revalidate
Info::
ETag present — enables conditional (304) responses
Cache-Control

max-age=0, private, must-revalidate

DirectiveValueMeaning
max-age0Cache for 0 seconds
private—Only browser cache, not CDN/proxy
must-revalidate—Must recheck with server after expiry
A
Page Weight Budget
1.0 MB transferred, 27 requests
PASS
1.0 MB transferred, 27 requests
Info::
Page weighs 1.1 MB (1.0 MB transferred)
Info::
Fonts are 281 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 281 KB
Info::
27 HTTP requests
Info::
Estimated 0.21 g CO2 per page load
1.0 MB / 2.4 MB budget
1.0 MB transferred
27 requests
0.21 g CO2 per page load
Images 515.6 KiB 50%
Fonts 281.5 KiB 27%
JavaScript 143.6 KiB 14%
CSS 75.6 KiB 7%
HTML 19.4 KiB 2%
Other 2.0 KiB 0%
0 2.4 MB 4.9 MB
Under budget

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

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+
JS Execution Cost
278ms total JS execution
PASS
278ms total JS execution
Info::
https://linuxfr.org/: 220ms CPU time
Info::
Unattributable: 58ms CPU time
Info::
Third-party scripts: 58ms (21% of total)

Main Thread Breakdown

Style & Layout 48% Other 24% Rendering 14% Script Evaluation 9%
ScriptTotalScriptingParse/CompileParty
https://linuxfr.org/220ms1ms0ms1st
Unattributable58ms2ms0ms3rd
A+
Font Loading
2 fonts (281 KB)
PASS
2 fonts (281 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

281 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 851 ms LCP 851 mshttps://linuxfr.org/fonts/Lato-Regular.woff2Lato-Regular.woff2 https://linuxfr.org/fonts/Lato-Regular.woff2 — 178.9 KiB — 0 ms — font-display: swaphttps://linuxfr.org/fonts/Merriweather-Regular.woff2Merriweather-Regular.woff2 https://linuxfr.org/fonts/Merriweather-Regular.woff2 — 102.6 KiB — 0 ms — font-display: swap
Lato-Regular.woff2 woff2 swap
Size 179 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
Merriweather-Regular.woff2 woff2 swap
Size 103 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • 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 ~141 KB and ~282 ms

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
Network Waterfall
27 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
21% of JavaScript execution is third-party
First-party Third-party 58ms · 0KB · €1/mo
Unattributable
Other
Optional
Execution 58ms
Transfer 0 KB
Monthly Cost €1/mo

How third-party costs are calculated

Real-User Performance (CrUX)
Field metrics from the Chrome User Experience Report
INFO

Chrome User Experience (CrUX)

Real-user metrics from the Chrome UX Report (2026-03-06 — 2026-04-02)

LCP (p75)

1082 ms

97% good

INP (p75)

50 ms

99% good

CLS (p75)

0.010

96% good

FCP (p75)

865 ms

TTFB (p75)

585 ms

This origin passes Core Web Vitals assessment
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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