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

100

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.

1.06 s

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

3.87 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.

0.693

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

4.43 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.

3.88 s

Page Load Progression

2.1 s

4.2 s

6.3 s

8.4 s

10.5 s

12.6 s

14.7 s

16.8 s

Checks

6 PASS 3 REVIEW 4 FIX

Page Weight Budget

Action

3.2 MB transferred, 49 requests

FIX

3.2 MB transferred, 49 requests

Page weighs 3.7 MB (3.2 MB transferred)

Images are 2.8 MB — compress or use modern formats

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

Got: 2.8 MB

49 HTTP requests

Estimated 0.68 g CO2 per page load

3.2 MB transferred

49 requests

0.68 g CO2 per page load

Images 2.8 MiB 87%

JavaScript 166.6 KiB 5%

Fonts 140.2 KiB 4%

Other 83.0 KiB 3%

CSS 31.9 KiB 1%

HTML 9.2 KiB 0%

Other 4.4 KiB 0%

Other 3.6 KiB 0%

Other 274 B 0%

0 2.4 MB 4.9 MB

Over 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

Third-Party Impact

Action

100% third-party, 0 ms blocking

FIX

100% third-party, 0 ms blocking

Third-party code accounts for 100% of page weight (3.2 MiB of 3.2 MiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

Page Weight Inventory

Action

49 resources · 3.2 MB · 65 KB savings available

FIX

49 resources · 3.2 MB · 65 KB savings available

Page weight 2.2 MB over 1MB target

Got: 3.2 MB Expected: ≤ 1 MB

~65 KB of savings available

48 third-party resources (100% of weight)

5 resources over 200KB

49 resources · 3.2 MiB · 48 third-party 2.2 MiB over 1MB target

Image 87% · 2.8 MiB

JavaScript 5% · 166.6 KiB

Font 4% · 140.2 KiB

Document 3% · 93.0 KiB

CSS 1% · 31.9 KiB

Other 0% · 4.7 KiB

~65.5 KiB of savings available

Remove unused JavaScript: 65.5 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

49 resources			3.2 MiB

HTTP Caching

Action

No cache headers

FIX

No cache headers

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.

Image Optimization

17 images, 0 KB saveable

REVIEW

17 images, 0 KB saveable

All images are well-optimized

17 images 2.8 MB

0 oversized -0 KB

17 legacy format

0 missing dimensions CLS risk

JS Bundles

6 scripts, 65 KB unused

REVIEW

6 scripts, 65 KB unused

https://piwik.uni-muenster.de/piwik.js: 65 KB unused (64%)

Consider code splitting or tree shaking to reduce unused code.

https://www.uni-muenster.de/wwu/js/main.js: unminified — 2 KB could be saved

Total unused JavaScript: 65 KB

65 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://piwik.uni-muenster.de/piwik.js	103 KB	65 KB (64%)	✓	3rd
https://www.uni-muenster.de/wwu/js/modernizr.wwu.js	4 KB	—	✓	3rd
https://www.uni-muenster.de/wwu/js/jquery.min.js	30 KB	—	✓	3rd
https://www.uni-muenster.de/wwu/js/main.js	11 KB	—	✗	3rd
https://www.uni-muenster.de/wwu/js/lazysizes.js	5 KB	—	✓	3rd
https://www.uni-muenster.de/wwu/js/owl.carousel2.js	13 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

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

All text resources are properly compressed.

A+

JS Execution Cost

499ms total JS execution

PASS

499ms total JS execution

https://www.uni-muenster.de/de/: 231ms CPU time

Unattributable: 151ms CPU time

https://www.uni-muenster.de/wwu/js/jquery.min.js: 118ms CPU time

Third-party scripts: 499ms (100% of total)

Main Thread Breakdown

Other 33% Style & Layout 27% Script Evaluation 22% Rendering 9% Parse HTML & CSS 5%

Script	Total	Scripting	Parse/Compile	Party
https://www.uni-muenster.de/de/	231ms	3ms	0ms	3rd
Unattributable	151ms	4ms	0ms	3rd
https://www.uni-muenster.de/wwu/js/jquery.min.js	118ms	73ms	3ms	3rd

A+

Font Loading

3 fonts (140 KB)

PASS

3 fonts (140 KB)

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

Web fonts

140 KB total

Render-blocking

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

metawebpro-bold.woff woff swap

Size 64 KB

Load time 655 ms

Start 2.8 s

Risk FOUT — text flashes from fallback to web font

Convert to woff2 for ~30% smaller file size

wwu_symbol.woff woff swap

Size 11 KB

Load time 920 ms

Start 2.8 s

Risk FOUT — text flashes from fallback to web font

Convert to woff2 for ~30% smaller file size

metawebpro-normal.woff woff swap

Size 65 KB

Load time 2.9 s

Start 2.8 s

Risk FOUT — text flashes from fallback to web font

Convert to woff2 for ~30% smaller file size

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)

Fixing the unchecked items could save ~42 KB and ~84 ms

A+

Resource Caching

All resources properly cached

PASS

All resources properly cached

No caching issues found

All static resources have appropriate caching headers.

A+

Critical Rendering Path

No render-blocking resources

PASS

No render-blocking resources

No render-blocking resources detected

A+

Resource Hints

No optimization needed

PASS

No optimization needed

No resource hint issues

Network Waterfall

49 requests over 15196ms

INFO

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 499ms · 39KB · €5/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
www.uni-muenster.de www.uni-muenster.de	Other	231ms	9 KB	—	€2/mo	Costly
Unattributable Unattributable	Other	151ms	0 KB	—	€2/mo	Optional
www.uni-muenster.de www.uni-muenster.de	Other	118ms	30 KB	—	€1/mo	Optional

www.uni-muenster.de

Other

Costly

Execution 231ms

Transfer 9 KB

Monthly Cost €2/mo

Unattributable

Other

Optional

Execution 151ms

Transfer 0 KB

Monthly Cost €2/mo

www.uni-muenster.de

Other

Optional

Execution 118ms

Transfer 30 KB

Monthly Cost €1/mo

These scripts may cost more than they're worth

www.uni-muenster.de adds 231ms 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

www.uni-muenster.de takes 231ms 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.