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https://ccc.de

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
91
GRADE
A
FIX
2
REVIEW
2
PASS
9
INFO
1

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.
92
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
81
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.

750 ms

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

805 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.

0.000

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

750 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.

805 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 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 (192.7 KiB of 192.8 KiB)
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.

C
Image Optimization
Action
8 images, 0 KB saveable
REVIEW
8 images, 0 KB saveable
Warning::
https://www.ccc.de/images/header.png?1736906356 is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ccc.de/images/chaosradio.png?173687506... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ccc.de/images/ds.png?1736875191 is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ccc.de/images/events.png?1736875302 is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
8 images 66 KB
0 oversized -0 KB
8 legacy format
4 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

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

Green Hosting

No green hosting detected

A+
Page Weight Budget
193 KB transferred, 20 requests
PASS
193 KB transferred, 20 requests
Info::
Page weighs 188 KB (193 KB transferred)
Info::
20 HTTP requests
Info::
Estimated 0.04 g CO2 per page load
193 KB / 2.4 MB budget
193 KB transferred
20 requests
0.04 g CO2 per page load
JavaScript 95.0 KiB 49%
Images 66.3 KiB 34%
HTML 14.8 KiB 8%
CSS 13.0 KiB 7%
Other 3.7 KiB 2%
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+
JS Execution Cost
No JS execution data
PASS
No JS execution data
Info::
No significant JS execution detected

Main Thread Breakdown

Other 48% Style & Layout 25% Script Evaluation 17% Parse HTML & CSS 4% Script Parsing & Compilation 3% Rendering 3%
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, 38 KB unused
PASS
7 scripts, 38 KB unused
Warning::
https://www.ccc.de/javascripts/jquery-1.3.2.min.js...: 38 KB unused (67%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 38 KB
38 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.ccc.de/javascripts/jquery-1.3.2.min.js?124665768356 KB38 KB (67%)✓3rd
https://www.ccc.de/javascripts/shadowbox/shadowbox.js?125319003521 KB—✓3rd
https://www.ccc.de/javascripts/public.js?17396744351 KB—✓3rd
https://www.ccc.de/javascripts/shadowbox/libraries/sizzle/sizzle.js13 KB—✓3rd
https://www.ccc.de/javascripts/shadowbox/languages/shadowbox-en.js1 KB—✓3rd
https://www.ccc.de/javascripts/shadowbox/players/shadowbox-img.js2 KB—✓3rd
https://www.ccc.de/javascripts/shadowbox/adapters/shadowbox-jquery.js1 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

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
20 resources · 193 KB · 38 KB savings available
PASS
20 resources · 193 KB · 38 KB savings available
Info::
Within 1MB page-weight target
Got: 193 KB
Warning::
19 third-party resources (100% of weight)
20 resources · 192.8 KiB · 19 third-party Within 1MB page-weight target
JavaScript 49% · 95.0 KiB
Image 36% · 69.8 KiB
Document 8% · 15.0 KiB
CSS 7% · 13.0 KiB

~37.6 KiB of savings available

Remove unused JavaScript: 37.6 KiB
Network Waterfall
20 requests over 591ms
INFO
0 ms 200 ms 400 ms 600 ms 800 ms FCP 750 ms LCP 805 mshttps://ccc.de// https://ccc.de/ — 302 — 194 B — 101 ms — http/1.1https://www.ccc.de/www.ccc.de/ https://www.ccc.de/ — 200 — 14.8 KiB — 172 ms — http/1.1https://www.ccc.de/stylesheets/ccc.css?1743181483www.ccc.de/stylesheets/ccc.css?1743... https://www.ccc.de/stylesheets/ccc.css?1743181483 — 200 — 10.8 KiB — 39 ms — http/1.1https://www.ccc.de/javascripts/jquery-1.3.2.min.js?1246657683www.ccc.de/javascripts/jquery-1.3.2... https://www.ccc.de/javascripts/jquery-1.3.2.min.js?1246657683 — 200 — 56.1 KiB — 174 ms — http/1.1https://www.ccc.de/javascripts/shadowbox/shadowbox.js?1253190035www.ccc.de/javascripts/shadowbox/sh... https://www.ccc.de/javascripts/shadowbox/shadowbox.js?1253190035 — 200 — 20.7 KiB — 144 ms — http/1.1https://www.ccc.de/stylesheets/shadowbox.css?1253190035www.ccc.de/stylesheets/shadowbox.cs... https://www.ccc.de/stylesheets/shadowbox.css?1253190035 — 200 — 2.2 KiB — 74 ms — http/1.1https://www.ccc.de/javascripts/public.js?1739674435www.ccc.de/javascripts/public.js?17... https://www.ccc.de/javascripts/public.js?1739674435 — 200 — 1.3 KiB — 111 ms — http/1.1https://www.ccc.de/images/header.png?1736906356www.ccc.de/images/header.png?173690... https://www.ccc.de/images/header.png?1736906356 — 200 — 14.2 KiB — 112 ms — http/1.1https://www.ccc.de/images/chaosradio.png?1736875067www.ccc.de/images/chaosradio.png?17... https://www.ccc.de/images/chaosradio.png?1736875067 — 200 — 13.0 KiB — 76 ms — http/1.1https://www.ccc.de/images/ds.png?1736875191www.ccc.de/images/ds.png?1736875191 https://www.ccc.de/images/ds.png?1736875191 — 200 — 2.5 KiB — 38 ms — http/1.1https://www.ccc.de/images/events.png?1736875302www.ccc.de/images/events.png?173687... https://www.ccc.de/images/events.png?1736875302 — 200 — 7.4 KiB — 38 ms — http/1.1https://www.ccc.de/images/media-ccc-de-banner.svg?1549308118www.ccc.de/images/media-ccc-de-bann... https://www.ccc.de/images/media-ccc-de-banner.svg?1549308118 — 200 — 6.4 KiB — 36 ms — http/1.1https://www.ccc.de/images/Fediverse.svg?1668911106www.ccc.de/images/Fediverse.svg?166... https://www.ccc.de/images/Fediverse.svg?1668911106 — 200 — 19.5 KiB — 37 ms — http/1.1https://www.ccc.de/javascripts/shadowbox/libraries/sizzle/sizzle.jswww.ccc.de/javascripts/shadowbox/li... https://www.ccc.de/javascripts/shadowbox/libraries/sizzle/sizzle.js — 200 — 12.5 KiB — 41 ms — http/1.1https://www.ccc.de/javascripts/shadowbox/languages/shadowbox-en.jswww.ccc.de/javascripts/shadowbox/la... https://www.ccc.de/javascripts/shadowbox/languages/shadowbox-en.js — 200 — 825 B — 39 ms — http/1.1https://www.ccc.de/javascripts/shadowbox/players/shadowbox-img.jswww.ccc.de/javascripts/shadowbox/pl... https://www.ccc.de/javascripts/shadowbox/players/shadowbox-img.js — 200 — 2.4 KiB — 38 ms — http/1.1https://www.ccc.de/javascripts/shadowbox/adapters/shadowbox-jquery.jswww.ccc.de/javascripts/shadowbox/ad... https://www.ccc.de/javascripts/shadowbox/adapters/shadowbox-jquery.js — 200 — 1.2 KiB — 38 ms — http/1.1https://www.ccc.de/images/Bluesky_Logo.svg?1737509920www.ccc.de/images/Bluesky_Logo.svg?... https://www.ccc.de/images/Bluesky_Logo.svg?1737509920 — 200 — 959 B — 37 ms — http/1.1https://www.ccc.de/images/left_column.pngwww.ccc.de/images/left_column.png https://www.ccc.de/images/left_column.png — 200 — 2.4 KiB — 36 ms — http/1.1https://www.ccc.de/favicon.icowww.ccc.de/favicon.ico https://www.ccc.de/favicon.ico — 200 — 3.5 KiB — 36 ms — http/1.1
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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