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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
94
GRADE
A
FIX
1
REVIEW
2
PASS
9
INFO
2

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

Mobile Desktop
99
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
67
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.
83
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.

334 ms

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

654 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.

0.053

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

377 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.

654 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
14
9 PASS 2 REVIEW 1 FIX
D
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.
Info::
ETag present — enables conditional (304) responses
Info::
Last-Modified header present

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

C
Image Optimization
Action
18 images, 0 KB saveable
REVIEW
18 images, 0 KB saveable
Warning::
https://www.fedoraproject.org/assets/images/logo-s... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.fedoraproject.org/assets/images/coreos... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.fedoraproject.org/assets/images/logos/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.fedoraproject.org/assets/images/digita... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.fedoraproject.org/assets/images/workst... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.fedoraproject.org/assets/images/kde-lo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.fedoraproject.org/assets/images/server... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.fedoraproject.org/assets/images/cloud-... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.fedoraproject.org/assets/images/IoT-lo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
18 images 189 KB
0 oversized -0 KB
18 legacy format
9 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

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

Green Hosting

No green hosting detected

A
Page Weight Budget
930 KB transferred, 33 requests
PASS
930 KB transferred, 33 requests
Info::
Page weighs 1.7 MB (930 KB transferred)
Info::
Fonts are 677 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 677 KB
Info::
33 HTTP requests
Info::
Estimated 0.19 g CO2 per page load
930 KB / 2.4 MB budget
930 KB transferred
33 requests
0.19 g CO2 per page load
Fonts 677.2 KiB 73%
Images 188.6 KiB 20%
CSS 35.3 KiB 4%
HTML 24.9 KiB 3%
Other 3.0 KiB 0%
JavaScript 690 B 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+
Third-Party Impact
No third-party resources
PASS
No third-party resources
Info::
No third-party resources detected
No third-party resources detected — all resources are first-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+
JS Execution Cost
158ms total JS execution
PASS
158ms total JS execution
Info::
https://www.fedoraproject.org/: 101ms CPU time
Info::
Unattributable: 57ms CPU time
Info::
Third-party scripts: 57ms (36% of total)

Main Thread Breakdown

Other 41% Style & Layout 41% Rendering 8% Parse HTML & CSS 7%
ScriptTotalScriptingParse/CompileParty
https://www.fedoraproject.org/101ms2ms0ms1st
Unattributable57ms1ms0ms3rd
A+
Font Loading
8 fonts (677 KB)
PASS
8 fonts (677 KB)
Info::
8 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

8

677 KB total

Render-blocking

0

of 8

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 334 ms LCP 654 mshttps://www.fedoraproject.org/fonts/open-sans/OpenSans-Regular.ttfOpenSans-Regular.ttf https://www.fedoraproject.org/fonts/open-sans/OpenSans-Regular.ttf — 77.3 KiB — 0 ms — font-display: swaphttps://www.fedoraproject.org/assets/webfonts/fa-solid-900.woff2fa-solid-900.woff2 https://www.fedoraproject.org/assets/webfonts/fa-solid-900.woff2 — 110.7 KiB — 0 ms — font-display: swaphttps://www.fedoraproject.org/fonts/montserrat/Montserrat-SemiBold.ttfMontserrat-SemiBold.ttf https://www.fedoraproject.org/fonts/montserrat/Montserrat-SemiBold.ttf — 86.3 KiB — 0 ms — font-display: swaphttps://www.fedoraproject.org/fonts/open-sans/OpenSans-Bold.ttfOpenSans-Bold.ttf https://www.fedoraproject.org/fonts/open-sans/OpenSans-Bold.ttf — 75.2 KiB — 0 ms — font-display: swaphttps://www.fedoraproject.org/fonts/montserrat/Montserrat-Regular.ttfMontserrat-Regular.ttf https://www.fedoraproject.org/fonts/montserrat/Montserrat-Regular.ttf — 86.2 KiB — 0 ms — font-display: swaphttps://www.fedoraproject.org/fonts/montserrat/Montserrat-Bold.ttfMontserrat-Bold.ttf https://www.fedoraproject.org/fonts/montserrat/Montserrat-Bold.ttf — 86.9 KiB — 0 ms — font-display: swaphttps://www.fedoraproject.org/fonts/open-sans/OpenSans-Medium.ttfOpenSans-Medium.ttf https://www.fedoraproject.org/fonts/open-sans/OpenSans-Medium.ttf — 77.5 KiB — 0 ms — font-display: swaphttps://www.fedoraproject.org/fonts/open-sans/OpenSans-SemiBold.ttfOpenSans-SemiBold.ttf https://www.fedoraproject.org/fonts/open-sans/OpenSans-SemiBold.ttf — 77.1 KiB — 0 ms — font-display: swap
OpenSans-Regular.ttf ttf swap
Size 77 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
fa-solid-900.woff2 woff2 swap
Size 111 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
Montserrat-SemiBold.ttf ttf swap
Size 86 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
OpenSans-Bold.ttf ttf swap
Size 75 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
Montserrat-Regular.ttf ttf swap
Size 86 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
Montserrat-Bold.ttf ttf swap
Size 87 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
OpenSans-Medium.ttf ttf swap
Size 78 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
OpenSans-SemiBold.ttf ttf swap
Size 77 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • 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 ~225 KB and ~450 ms

A+
JS Bundles
1 scripts, 0 KB unused
PASS
1 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.fedoraproject.org/js/darkmode.js1 KB—✓1st
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
33 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
36% of JavaScript execution is third-party
First-party Third-party 57ms · 0KB · $1/mo
Unattributable
Other
Optional
Execution 57ms
Transfer 0 KB
Monthly Cost $1/mo

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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