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https://www.ubuntu.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
76
GRADE
C
FIX
4
REVIEW
3
PASS
5
INFO
2

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

Mobile Desktop
88
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
89
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.
92
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.

1.11 s

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

1.68 s

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

153 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.012

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

1.11 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.

3.35 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
5 PASS 3 REVIEW 4 FIX
D
Page Weight Budget
Action
2.2 MB transferred, 67 requests
FIX
2.2 MB transferred, 67 requests
Info::
Page weighs 6.6 MB (2.2 MB transferred)
Warning::
JavaScript is 1.6 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.6 MB
Info::
Fonts are 367 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 367 KB
Info::
67 HTTP requests
Info::
Estimated 0.47 g CO2 per page load
2.2 MB / 2.4 MB budget
2.2 MB transferred
67 requests
0.47 g CO2 per page load
JavaScript 1.6 MiB 70%
Fonts 367.2 KiB 16%
CSS 141.9 KiB 6%
Images 107.6 KiB 5%
HTML 37.2 KiB 2%
Other 15.3 KiB 1%
Other 9.0 KiB 0%
Other 8.5 KiB 0%
Other 4.5 KiB 0%
0 2.4 MB 4.9 MB
Approaching limit

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

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

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 (2.2 MiB of 2.2 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Bundles
Action
20 scripts, 682 KB unused
FIX
20 scripts, 682 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-PGQQ...: 115 KB unused (66%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-5LTL...: 107 KB unused (62%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/destination?...: 70 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/destination?...: 68 KB unused (50%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/destination?...: 66 KB unused (49%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 682 KB
682 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-PGQQ61N4N6&cx=c&gtm=4e6460175 KB115 KB (66%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-5LTL1CNEJM&cx=c&gtm=4e6460174 KB107 KB (62%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=G-PGQQ61N4N6&cx=c&gtm=4e6460175 KB70 KB (40%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=AW-604028040&cx=c&gtm=4e6460136 KB68 KB (50%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=AW-1012391776&cx=c&gtm=4e6460133 KB66 KB (49%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-K92JCQ181 KB65 KB (36%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=DC-10451423&cx=c&gtm=4e6460129 KB65 KB (50%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=G-5LTL1CNEJM&cx=c&gtm=4e6460174 KB63 KB (36%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=AW-608589488&cx=c&gtm=4e6460144 KB63 KB (44%)✓3rd
https://ubuntu.com/static/js/src/cookie-policy-with-callback.js?v=77068335 KB—✓3rd

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

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

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

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
Image Optimization
16 images, 0 KB saveable
REVIEW
16 images, 0 KB saveable
Info::
All images are well-optimized
16 images 108 KB
0 oversized -0 KB
6 legacy format
0 missing dimensions CLS risk
B
JS Execution Cost
760ms total JS execution
REVIEW
760ms total JS execution
Info::
https://ubuntu.com/: 230ms CPU time
Info::
Unattributable: 167ms CPU time
Info::
https://www.googletagmanager.com/gtag/destination?...: 132ms CPU time
Info::
https://ubuntu.com/static/js/dist/main.js?v=a3482b...: 87ms CPU time
Info::
https://www.googletagmanager.com/gtag/destination?...: 82ms CPU time
Warning::
Third-party scripts: 760ms (100% of total)

Main Thread Breakdown

Script Evaluation 48% Other 21% Script Parsing & Compilation 11% Style & Layout 10% Parse HTML & CSS 4% Garbage Collection 4%
ScriptTotalScriptingParse/CompileParty
https://ubuntu.com/230ms63ms2ms3rd
Unattributable167ms3ms0ms3rd
https://www.googletagmanager.com/gtag/destination?id=G-5LTL1CNEJM&cx=c&gtm=4e6460132ms102ms24ms3rd
https://ubuntu.com/static/js/dist/main.js?v=a3482bc87ms59ms6ms3rd
https://www.googletagmanager.com/gtag/destination?id=G-PGQQ61N4N6&cx=c&gtm=4e646082ms61ms16ms3rd
https://www.googletagmanager.com/gtag/destination?id=AW-608589488&cx=c&gtm=4e646063ms47ms9ms3rd
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+
Font Loading
5 fonts (367 KB)
PASS
5 fonts (367 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

367 KB total

Render-blocking

0

of 5

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s FCP 1.1 s LCP 1.7 shttps://assets.ubuntu.com/v1/f1ea362b-Ubuntu%5Bwdth,wght%5D-latin-v0.896a.woff2f1ea362b-Ubuntu%5Bwdth,... https://assets.ubuntu.com/v1/f1ea362b-Ubuntu%5Bwdth,wght%5D-latin-v0.896a.woff2 — 93.5 KiB — 0 ms — font-display: swaphttps://assets.ubuntu.com/v1/90b59210-Ubuntu-Italic%5Bwdth,wght%5D-latin-v0.896a.woff290b59210-Ubuntu-Italic%... https://assets.ubuntu.com/v1/90b59210-Ubuntu-Italic%5Bwdth,wght%5D-latin-v0.896a.woff2 — 74.6 KiB — 0 ms — font-display: swaphttps://assets.ubuntu.com/v1/d5fc1819-UbuntuMono%5Bwght%5D-latin-v0.869.woff2d5fc1819-UbuntuMono%5Bw... https://assets.ubuntu.com/v1/d5fc1819-UbuntuMono%5Bwght%5D-latin-v0.869.woff2 — 31.0 KiB — 0 ms — font-display: swaphttps://assets.ubuntu.com/v1/f1ea362b-Ubuntu[wdth,wght]-latin-v0.896a.woff2f1ea362b-Ubuntu[wdth,wg... https://assets.ubuntu.com/v1/f1ea362b-Ubuntu[wdth,wght]-latin-v0.896a.woff2 — 93.5 KiB — 0 ms — font-display: swaphttps://assets.ubuntu.com/v1/90b59210-Ubuntu-Italic[wdth,wght]-latin-v0.896a.woff290b59210-Ubuntu-Italic[... https://assets.ubuntu.com/v1/90b59210-Ubuntu-Italic[wdth,wght]-latin-v0.896a.woff2 — 74.6 KiB — 0 ms — font-display: swap
f1ea362b-Ubuntu%5Bwdth,... woff2 swap
Size 93 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
90b59210-Ubuntu-Italic%... woff2 swap
Size 75 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
d5fc1819-UbuntuMono%5Bw... woff2 swap
Size 31 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
f1ea362b-Ubuntu[wdth,wg... woff2 swap
Size 93 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
90b59210-Ubuntu-Italic[... woff2 swap
Size 75 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+
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
67 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
100% of JavaScript execution is third-party
First-party Third-party 760ms · 568KB · €8/mo
ubuntu.com
Other
Costly
Execution 230ms
Transfer 37 KB
Monthly Cost €2/mo
Unattributable
Other
Optional
Execution 167ms
Transfer 0 KB
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Optional
Execution 132ms
Transfer 174 KB
Unused 36%
Monthly Cost €1/mo
ubuntu.com
Other
Optional
Execution 87ms
Transfer 37 KB
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 82ms
Transfer 175 KB
Unused 40%
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 63ms
Transfer 144 KB
Unused 44%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • ubuntu.com adds 230ms and costs ~€2/month

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

ubuntu.com takes 230ms 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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