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https://gnu.org

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
85
GRADE
B
FIX
3
REVIEW
2
PASS
8
INFO
2

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

74
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
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.
82
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.

1.80 s

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

5.76 s

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

222 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.

2.17 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.

5.79 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
15
8 PASS 2 REVIEW 3 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 (795.6 KiB of 796.0 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
JS Execution Cost
Action
2029ms total JS execution
FIX
2029ms total JS execution
Warning::
https://www.gnu.org/: 1653ms CPU time
Warning::
Unattributable: 376ms CPU time
Warning::
Third-party scripts: 2029ms (100% of total)

Main Thread Breakdown

Other 46% Style & Layout 28% Rendering 23%
ScriptTotalScriptingParse/CompileParty
https://www.gnu.org/1653ms9ms1ms3rd
Unattributable376ms11ms0ms3rd
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
Warning::
https://www.gnu.org/graphics/snowflake-purple.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
16 images 690 KB
0 oversized -0 KB
13 legacy format
1 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

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

Green Hosting

No green hosting detected

A
Page Weight Budget
796 KB transferred, 26 requests
PASS
796 KB transferred, 26 requests
Info::
Page weighs 841 KB (796 KB transferred)
Info::
26 HTTP requests
Info::
Estimated 0.16 g CO2 per page load
796 KB / 2.4 MB budget
796 KB transferred
26 requests
0.16 g CO2 per page load
Images 689.8 KiB 87%
Other 80.5 KiB 10%
HTML 10.1 KiB 1%
CSS 7.2 KiB 1%
Other 5.9 KiB 1%
Other 2.5 KiB 0%
0 2.4 MB 4.9 MB
Under budget
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
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
No JavaScript
PASS
No JavaScript
Info::
No JavaScript bundles
No JavaScript files loaded.
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
26 resources · 796 KB · 0 KB savings available
PASS
26 resources · 796 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 796 KB
Warning::
25 third-party resources (100% of weight)
Info::
1 resources over 200KB
26 resources · 796.0 KiB · 25 third-party Within 1MB page-weight target
Image 87% · 692.0 KiB
Media 10% · 80.5 KiB
Document 1% · 10.4 KiB
CSS 1% · 7.2 KiB
Other 1% · 5.9 KiB
Network Waterfall
26 requests over 1357ms
INFO
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s FCP 1.8 s LCP 5.8 shttps://gnu.org// https://gnu.org/ — 301 — 376 B — 269 ms — http/1.1https://www.gnu.org/www.gnu.org/ https://www.gnu.org/ — 200 — 10.1 KiB — 329 ms — http/1.1https://www.gnu.org/layout.min.csswww.gnu.org/layout.min.css https://www.gnu.org/layout.min.css — 200 — 5.5 KiB — 102 ms — http/1.1https://www.gnu.org/graphics/heckert_gnu.transp.small.pngwww.gnu.org/graphics/heckert_gnu.tr... https://www.gnu.org/graphics/heckert_gnu.transp.small.png — 200 — 33.5 KiB — 309 ms — http/1.1https://static.gnu.org/nosvn/videos/escape-to-freedom/thumbnails/festival.jpegstatic.gnu.org/nosvn/videos/escape-... https://static.gnu.org/nosvn/videos/escape-to-freedom/thumbnails/festival.jpeg — 200 — 526.4 KiB — 683 ms — http/1.1https://www.gnu.org/graphics/snowflake-purple.pngwww.gnu.org/graphics/snowflake-purp... https://www.gnu.org/graphics/snowflake-purple.png — 200 — 14.5 KiB — 186 ms — http/1.1https://www.gnu.org/graphics/icons/search.pngwww.gnu.org/graphics/icons/search.p... https://www.gnu.org/graphics/icons/search.png — 200 — 17.6 KiB — 307 ms — http/1.1https://www.gnu.org/graphics/icons/translations.pngwww.gnu.org/graphics/icons/translat... https://www.gnu.org/graphics/icons/translations.png — 200 — 3.9 KiB — 248 ms — http/1.1https://www.gnu.org/distros/screenshots/dragora-tde-thumb.jpgwww.gnu.org/distros/screenshots/dra... https://www.gnu.org/distros/screenshots/dragora-tde-thumb.jpg — 200 — 14.0 KiB — 308 ms — http/1.1https://static.gnu.org/nosvn/videos/escape-to-freedom/videos/escape-to-freedom-720p.webmstatic.gnu.org/nosvn/videos/escape-... https://static.gnu.org/nosvn/videos/escape-to-freedom/videos/escape-to-freedom-720p.webm — 206 — 80.5 KiB — 531 ms — http/1.1https://static.gnu.org/nosvn/videos/escape-to-freedom/captions/escape-to-freedom_en.vttstatic.gnu.org/nosvn/videos/escape-... https://static.gnu.org/nosvn/videos/escape-to-freedom/captions/escape-to-freedom_en.vtt — 200 — 5.9 KiB — 322 ms — http/1.1data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4KPCEtLSBHZW5lcmF0b3I6I…data:image/svg+xml;base64,PD94bWwgd... data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4KPCEtLSBHZW5lcmF0b3I6I… — 200 — 0 B — 0 ms — datadata:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4KPCEtLSBHZW5lcmF0b3I6I…data:image/svg+xml;base64,PD94bWwgd... data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4KPCEtLSBHZW5lcmF0b3I6I… — 200 — 0 B — 0 ms — datadata:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4KPHN2ZyB2ZXJzaW9uPSIxL…data:image/svg+xml;base64,PD94bWwgd... data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4KPHN2ZyB2ZXJzaW9uPSIxL… — 200 — 0 B — 0 ms — datahttps://www.gnu.org/distros/screenshots/guix1.5-plasma-thumb.pngwww.gnu.org/distros/screenshots/gui... https://www.gnu.org/distros/screenshots/guix1.5-plasma-thumb.png — 200 — 23.2 KiB — 217 ms — http/1.1data:image/svg+xml;base64,PHN2ZyBmaWxsPSJXaW5kb3ciIGhlaWdodD0iMjQiIHZpZXdCb3g9IjAgMCAyNCAyNCIgd2lkd…data:image/svg+xml;base64,PHN2ZyBma... data:image/svg+xml;base64,PHN2ZyBmaWxsPSJXaW5kb3ciIGhlaWdodD0iMjQiIHZpZXdCb3g9IjAgMCAyNCAyNCIgd2lkd… — 200 — 0 B — 0 ms — datadata:image/svg+xml;base64,PHN2ZyBmaWxsPSJXaW5kb3ciIGhlaWdodD0iMjQiIHZpZXdCb3g9IjAgMCAyNCAyNCIgd2lkd…data:image/svg+xml;base64,PHN2ZyBma... data:image/svg+xml;base64,PHN2ZyBmaWxsPSJXaW5kb3ciIGhlaWdodD0iMjQiIHZpZXdCb3g9IjAgMCAyNCAyNCIgd2lkd… — 200 — 0 B — 0 ms — datadata:image/svg+xml;base64,PHN2ZyBmaWxsPSJXaW5kb3ciIGhlaWdodD0iMjQiIHZpZXdCb3g9IjAgMCAyNCAyNCIgd2lkd…data:image/svg+xml;base64,PHN2ZyBma... data:image/svg+xml;base64,PHN2ZyBmaWxsPSJXaW5kb3ciIGhlaWdodD0iMjQiIHZpZXdCb3g9IjAgMCAyNCAyNCIgd2lkd… — 200 — 0 B — 0 ms — datahttps://www.gnu.org/distros/screenshots/hyperbola-i3-thumb.jpgwww.gnu.org/distros/screenshots/hyp... https://www.gnu.org/distros/screenshots/hyperbola-i3-thumb.jpg — 200 — 8.5 KiB — 78 ms — http/1.1https://www.gnu.org/distros/screenshots/parabola2020-lxde-thumb.jpgwww.gnu.org/distros/screenshots/par... https://www.gnu.org/distros/screenshots/parabola2020-lxde-thumb.jpg — 200 — 5.1 KiB — 81 ms — http/1.1https://www.gnu.org/distros/screenshots/pureos10-gnome3-thumb.jpgwww.gnu.org/distros/screenshots/pur... https://www.gnu.org/distros/screenshots/pureos10-gnome3-thumb.jpg — 200 — 20.2 KiB — 76 ms — http/1.1https://www.gnu.org/distros/screenshots/trisquel11-mate-thumb.jpgwww.gnu.org/distros/screenshots/tri... https://www.gnu.org/distros/screenshots/trisquel11-mate-thumb.jpg — 200 — 18.5 KiB — 76 ms — http/1.1https://www.gnu.org/feed-icon-30x30.pngwww.gnu.org/feed-icon-30x30.png https://www.gnu.org/feed-icon-30x30.png — 200 — 2.1 KiB — 75 ms — http/1.1https://www.gnu.org/graphics/fsf-logo-notext-small.pngwww.gnu.org/graphics/fsf-logo-notex... https://www.gnu.org/graphics/fsf-logo-notext-small.png — 200 — 2.4 KiB — 79 ms — http/1.1https://www.gnu.org/print.min.csswww.gnu.org/print.min.css https://www.gnu.org/print.min.css — 200 — 1.7 KiB — 79 ms — http/1.1https://www.gnu.org/graphics/gnu-head-mini.pngwww.gnu.org/graphics/gnu-head-mini.... https://www.gnu.org/graphics/gnu-head-mini.png — 200 — 2.2 KiB — 76 ms — http/1.1
HTML JavaScript CSS Images Fonts XHR/Fetch Other
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 2029ms · 10KB · $27/mo
www.gnu.org
Other
Costly
Execution 1653ms
Transfer 10 KB
Monthly Cost $22/mo
Unattributable
Other
Costly
Execution 376ms
Transfer 0 KB
Monthly Cost $5/mo

These scripts may cost more than they're worth

  • www.gnu.org adds 1653ms and costs ~$22/month
  • Unattributable adds 376ms and costs ~$5/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

www.gnu.org takes 1653ms 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

Unattributable takes 376ms 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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