Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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

Mobile Desktop

Performance

Accessibility

Best Practices

SEO

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

888 ms

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

1.50 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.

0.229

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

888 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.

1.54 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

7 PASS 5 REVIEW 1 FIX

HTTP Caching

Action

no-store (uncacheable)

FIX

no-store (uncacheable)

Cache-Control: no-store prevents all caching

Intentional for dynamic content, but increases server load for every page view.

Got: private, no-store, max-age=0

No ETag or Last-Modified header

Conditional requests (304 Not Modified) are not possible without validators.

Cache-Control

private, no-store, max-age=0

Directive	Value	Meaning
private	—	Only browser cache, not CDN/proxy
no-store	—	Never cache this response
max-age	0	Cache for 0 seconds

Page Weight Budget

Action

1.9 MB transferred, 32 requests

REVIEW

1.9 MB transferred, 32 requests

Page weighs 2.1 MB (1.9 MB transferred)

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

CSS is 294 KB — consider purging unused styles

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Got: 294 KB

32 HTTP requests

Estimated 0.40 g CO2 per page load

1.9 MB transferred

32 requests

0.40 g CO2 per page load

Images 1.0 MiB 53%

JavaScript 474.0 KiB 24%

CSS 293.6 KiB 15%

Fonts 100.2 KiB 5%

HTML 44.8 KiB 2%

Other 4.7 KiB 0%

Other 1.2 KiB 0%

Other 305 B 0%

0 2.4 MB 4.9 MB

Approaching limit

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

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Why this matters

CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.

Source: web.dev

Image Optimization

17 images, 0 KB saveable

REVIEW

17 images, 0 KB saveable

All images are well-optimized

17 images 1.0 MB

0 oversized -0 KB

17 legacy format

0 missing dimensions CLS risk

JS Bundles

Action

3 scripts, 282 KB unused

REVIEW

3 scripts, 282 KB unused

https://uni-tuebingen.de/typo3temp/assets/compress...: 225 KB unused (60%)

Consider code splitting or tree shaking to reduce unused code.

https://uni-tuebingen.de/_assets/948410ace0dfa9ad0...: 57 KB unused (75%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 282 KB

282 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://uni-tuebingen.de/typo3temp/assets/compressed/merged-f74453d11ab0afcdd8d11488cf50acab.js?1772631307	375 KB	225 KB (60%)	✓	1st
https://uni-tuebingen.de/_assets/948410ace0dfa9ad00627133d9ca8a23/JavaScript/Powermail/Form.min.js?1753167604	77 KB	57 KB (75%)	✓	1st
https://vitruv.uni-tuebingen.de/piwik/piwik.js	22 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

Page Weight Inventory

Action

32 resources · 1.9 MB · 282 KB savings available

REVIEW

32 resources · 1.9 MB · 282 KB savings available

Page weight 945 KB over 1MB target

Got: 1.9 MB Expected: ≤ 1 MB

~282 KB of savings available

2 third-party resources (1% of weight)

2 resources over 200KB

32 resources · 1.9 MiB · 2 third-party 944.8 KiB over 1MB target

Image 54% · 1.0 MiB

JavaScript 24% · 474.0 KiB

CSS 15% · 293.6 KiB

Font 5% · 100.2 KiB

Document 2% · 44.8 KiB

Other 0% · 1.5 KiB

~281.7 KiB of savings available

Remove unused JavaScript: 281.7 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

32 resources			1.9 MiB

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

A+

Third-Party Impact

1% third-party, 0 ms blocking

PASS

1% third-party, 0 ms blocking

Third-party code accounts for 1% of page weight (22.4 KiB of 1.9 MiB)

Third-party blocking time is low (0 ms)

99%

First-party Third-party

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

JS Execution Cost

225ms total JS execution

PASS

225ms total JS execution

https://uni-tuebingen.de/: 97ms CPU time

https://uni-tuebingen.de/typo3temp/assets/compress...: 75ms CPU time

Unattributable: 53ms CPU time

Third-party scripts: 53ms (24% of total)

Main Thread Breakdown

Style & Layout 31% Script Evaluation 28% Other 26% Parse HTML & CSS 6% Script Parsing & Compilation 5% Rendering 5%

Script	Total	Scripting	Parse/Compile	Party
https://uni-tuebingen.de/	97ms	3ms	0ms	1st
https://uni-tuebingen.de/typo3temp/assets/compressed/merged-f74453d11ab0afcdd8d11488cf50acab.js?1772631307	75ms	53ms	8ms	1st
Unattributable	53ms	3ms	0ms	3rd

A+

Font Loading

5 fonts (100 KB)

PASS

5 fonts (100 KB)

5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

100 KB total

Render-blocking

of 5

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

OpenSans-Regular-webfon... woff swap

Size 21 KB

Load time 41 ms

Start 397 ms