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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
87
GRADE
B
FIX
2
REVIEW
3
PASS
8
INFO
1

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

Mobile Desktop
82
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
68
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
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.

1.06 s

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

1.91 s

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.

0.169

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

1.21 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.

1.91 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 s
Checks
14
8 PASS 3 REVIEW 2 FIX
D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (1.1 MiB of 1.1 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
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.

No Cache-Control header

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

B
Page Weight Budget
1.1 MB transferred, 24 requests
REVIEW
1.1 MB transferred, 24 requests
Info::
Page weighs 1.2 MB (1.1 MB transferred)
Warning::
Images are 1.0 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.0 MB
Info::
24 HTTP requests
Info::
Estimated 0.23 g CO2 per page load
1.1 MB / 2.4 MB budget
1.1 MB transferred
24 requests
0.23 g CO2 per page load
Images 1.0 MiB 94%
JavaScript 45.8 KiB 4%
CSS 14.8 KiB 1%
HTML 5.1 KiB 0%
Other 3.0 KiB 0%
0 2.4 MB 4.9 MB
Under budget

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

C
Image Optimization
Action
10 images, 0 KB saveable
REVIEW
10 images, 0 KB saveable
Warning::
https://www.virtualbox.org/graphics/vbox-new-logo.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.virtualbox.org/graphics/user.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.virtualbox.org/graphics/community.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.virtualbox.org/graphics/training.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.virtualbox.org/graphics/user-manual.pn... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
10 images 1.0 MB
0 oversized -0 KB
10 legacy format
5 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

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

Green Hosting

No green hosting detected

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
No JS execution data
PASS
No JS execution data
Info::
No significant JS execution detected

Main Thread Breakdown

Other 37% Style & Layout 27% Script Evaluation 24% Parse HTML & CSS 5% Script Parsing & Compilation 4%
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
A+
JS Bundles
7 scripts, 0 KB unused
PASS
7 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.virtualbox.org/chrome/common/js/jquery.js31 KB—✓3rd
https://www.virtualbox.org/chrome/common/js/jquery-migrate.js5 KB—✓3rd
https://www.virtualbox.org/chrome/common/js/babel.js2 KB—✓3rd
https://www.virtualbox.org/chrome/common/js/trac.js3 KB—✓3rd
https://www.virtualbox.org/chrome/common/js/search.js2 KB—✓3rd
https://www.virtualbox.org/chrome/common/js/folding.js1 KB—✓3rd
https://www.virtualbox.org/chrome/common/js/wiki.js1 KB—✓3rd
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
A
Page Weight Inventory
24 resources · 1.1 MB · 0 KB savings available
PASS
24 resources · 1.1 MB · 0 KB savings available
Warning::
Page weight 93 KB over 1MB target
Got: 1.1 MB Expected: ≤ 1 MB
Warning::
23 third-party resources (100% of weight)
Info::
2 resources over 200KB
24 resources · 1.1 MiB · 23 third-party 92.6 KiB over 1MB target
Image 94% · 1.0 MiB
JavaScript 4% · 45.8 KiB
CSS 1% · 14.8 KiB
Document 0% · 5.2 KiB
Network Waterfall
24 requests over 1094ms
INFO
0 ms 500 ms 1.0 s 1.5 s 2.0 s FCP 1.1 s LCP 1.9 shttps://virtualbox.org// https://virtualbox.org/ — 301 — 180 B — 556 ms — http/1.1https://www.virtualbox.org/www.virtualbox.org/ https://www.virtualbox.org/ — 200 — 5.1 KiB — 356 ms — h2https://www.virtualbox.org/chrome/common/css/trac.csswww.virtualbox.org/chrome/common/cs... https://www.virtualbox.org/chrome/common/css/trac.css — 200 — 7.3 KiB — 17 ms — h2https://www.virtualbox.org/chrome/common/css/wiki.csswww.virtualbox.org/chrome/common/cs... https://www.virtualbox.org/chrome/common/css/wiki.css — 200 — 2.3 KiB — 19 ms — h2https://www.virtualbox.org/chrome/common/js/jquery.jswww.virtualbox.org/chrome/common/js... https://www.virtualbox.org/chrome/common/js/jquery.js — 200 — 30.7 KiB — 39 ms — h2https://www.virtualbox.org/chrome/common/js/jquery-migrate.jswww.virtualbox.org/chrome/common/js... https://www.virtualbox.org/chrome/common/js/jquery-migrate.js — 200 — 5.1 KiB — 25 ms — h2https://www.virtualbox.org/chrome/common/js/babel.jswww.virtualbox.org/chrome/common/js... https://www.virtualbox.org/chrome/common/js/babel.js — 200 — 2.5 KiB — 27 ms — h2https://www.virtualbox.org/chrome/common/js/trac.jswww.virtualbox.org/chrome/common/js... https://www.virtualbox.org/chrome/common/js/trac.js — 200 — 3.2 KiB — 29 ms — h2https://www.virtualbox.org/chrome/common/js/search.jswww.virtualbox.org/chrome/common/js... https://www.virtualbox.org/chrome/common/js/search.js — 200 — 1.6 KiB — 30 ms — h2https://www.virtualbox.org/chrome/common/js/folding.jswww.virtualbox.org/chrome/common/js... https://www.virtualbox.org/chrome/common/js/folding.js — 200 — 1.4 KiB — 32 ms — h2https://www.virtualbox.org/chrome/common/js/wiki.jswww.virtualbox.org/chrome/common/js... https://www.virtualbox.org/chrome/common/js/wiki.js — 200 — 1.3 KiB — 33 ms — h2https://www.virtualbox.org/chrome/site/style.csswww.virtualbox.org/chrome/site/styl... https://www.virtualbox.org/chrome/site/style.css — 200 — 4.2 KiB — 18 ms — h2https://www.virtualbox.org/graphics/vboxlogodown.pngwww.virtualbox.org/graphics/vboxlog... https://www.virtualbox.org/graphics/vboxlogodown.png — 200 — 12.3 KiB — 34 ms — h2https://www.virtualbox.org/graphics/vbox-new-logo.pngwww.virtualbox.org/graphics/vbox-ne... https://www.virtualbox.org/graphics/vbox-new-logo.png — 200 — 62.2 KiB — 38 ms — h2https://www.virtualbox.org/chrome/common/css/code.csswww.virtualbox.org/chrome/common/cs... https://www.virtualbox.org/chrome/common/css/code.css — 200 — 1.1 KiB — 29 ms — h2https://www.virtualbox.org/graphics/user.pngwww.virtualbox.org/graphics/user.pn... https://www.virtualbox.org/graphics/user.png — 200 — 7.6 KiB — 32 ms — h2https://www.virtualbox.org/graphics/community.pngwww.virtualbox.org/graphics/communi... https://www.virtualbox.org/graphics/community.png — 200 — 21.4 KiB — 30 ms — h2https://www.virtualbox.org/graphics/user-manual.pngwww.virtualbox.org/graphics/user-ma... https://www.virtualbox.org/graphics/user-manual.png — 200 — 8.8 KiB — 12 ms — h2https://www.virtualbox.org/graphics/training.pngwww.virtualbox.org/graphics/trainin... https://www.virtualbox.org/graphics/training.png — 200 — 18.2 KiB — 14 ms — h2https://www.virtualbox.org/chrome/common/trac_logo_mini.pngwww.virtualbox.org/chrome/common/tr... https://www.virtualbox.org/chrome/common/trac_logo_mini.png — 200 — 2.0 KiB — 15 ms — h2https://www.virtualbox.org/graphics/patterned-background.pngwww.virtualbox.org/graphics/pattern... https://www.virtualbox.org/graphics/patterned-background.png — 200 — 453.1 KiB — 44 ms — h2https://www.virtualbox.org/graphics/dark-triangles.pngwww.virtualbox.org/graphics/dark-tr... https://www.virtualbox.org/graphics/dark-triangles.png — 200 — 461.0 KiB — 58 ms — h2https://www.virtualbox.org/graphics/oracle-logo-new.svgwww.virtualbox.org/graphics/oracle-... https://www.virtualbox.org/graphics/oracle-logo-new.svg — 200 — 1.1 KiB — 50 ms — h2https://www.virtualbox.org/favicon.icowww.virtualbox.org/favicon.ico https://www.virtualbox.org/favicon.ico — 200 — 2.9 KiB — 15 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
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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