Performance

· 17 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

100

Accessibility

100

Best Practices

100

SEO

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

3.97 s

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

16.74 s

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

742 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.

12.92 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.

20.49 s

Page Load Progression

872 ms

1.7 s

2.6 s

3.5 s

4.4 s

5.2 s

6.1 s

7.0 s

Checks

7 PASS 2 REVIEW 6 FIX

Page Weight Budget

Action

4.3 MB transferred, 34 requests

FIX

4.3 MB transferred, 34 requests

Page weighs 9.3 MB (4.3 MB transferred)

Images are 2.7 MB — compress or use modern formats

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

Got: 2.7 MB

JavaScript is 1.1 MB — consider code splitting or lazy loading

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

Got: 1.1 MB

CSS is 261 KB — consider purging unused styles

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

Got: 261 KB

34 HTTP requests

Estimated 0.90 g CO2 per page load

4.3 MB transferred

34 requests

0.90 g CO2 per page load

Images 2.7 MiB 64%

JavaScript 1.1 MiB 25%

CSS 260.6 KiB 6%

HTML 132.4 KiB 3%

Fonts 72.0 KiB 2%

Other 43.0 KiB 1%

Other 4.3 KiB 0%

Other 773 B 0%

Other 234 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

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

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

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 (4.3 MiB of 4.3 MiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

JS Execution Cost

Action

5089ms total JS execution

FIX

5089ms total JS execution

https://www.dlr.de/static/js/client.6ed9ea02.chunk...: 2400ms CPU time

https://www.dlr.de/de: 1722ms CPU time

Unattributable: 642ms CPU time

https://www.dlr.de/static/css/client.68b2ae8b.chun...: 271ms CPU time

https://www.dlr.de/matomo.js: 54ms CPU time

Third-party scripts: 5089ms (100% of total)

Main Thread Breakdown

Script Evaluation 38% Other 28% Style & Layout 12% Script Parsing & Compilation 11% Parse HTML & CSS 6% Rendering 4%

Script	Total	Scripting	Parse/Compile	Party
https://www.dlr.de/static/js/client.6ed9ea02.chunk.js	2400ms	1756ms	459ms	3rd
https://www.dlr.de/de	1722ms	123ms	93ms	3rd
Unattributable	642ms	17ms	0ms	3rd
https://www.dlr.de/static/css/client.68b2ae8b.chunk.css	271ms	0ms	0ms	3rd
https://www.dlr.de/matomo.js	54ms	38ms	15ms	3rd

JS Bundles

Action

3 scripts, 623 KB unused

FIX

3 scripts, 623 KB unused

https://www.dlr.de/static/js/client.6ed9ea02.chunk...: 623 KB unused (59%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 623 KB

623 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.dlr.de/static/js/client.6ed9ea02.chunk.js	1051 KB	623 KB (59%)	✓	3rd
https://www.dlr.de/static/js/runtime~client.de9847bf.js	2 KB	—	✓	3rd
https://www.dlr.de/matomo.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

Page Weight Inventory

Action

34 resources · 4.3 MB · 623 KB savings available

FIX

34 resources · 4.3 MB · 623 KB savings available

Page weight 3.3 MB over 1MB target

Got: 4.3 MB Expected: ≤ 1 MB

~623 KB of savings available

33 third-party resources (100% of weight)

4 resources over 200KB

34 resources · 4.3 MiB · 33 third-party 3.3 MiB over 1MB target

Image 64% · 2.7 MiB

JavaScript 25% · 1.1 MiB

CSS 6% · 260.6 KiB

Document 3% · 132.6 KiB

Font 2% · 72.0 KiB

Other 1% · 44.1 KiB

~623.0 KiB of savings available

Remove unused JavaScript: 623.0 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

34 resources			4.3 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

16 images, 0 KB saveable

REVIEW

16 images, 0 KB saveable

All images are well-optimized

16 images 2.7 MB

0 oversized -0 KB

14 legacy format

0 missing dimensions CLS risk

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+

Font Loading

3 fonts (72 KB)

PASS

3 fonts (72 KB)

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

Web fonts

72 KB total

Render-blocking

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

FrutigerLTW02-55Roman.b... woff2 swap

Size 23 KB

Load time 884 ms

Start 4.3 s

Risk FOUT — text flashes from fallback to web font

FrutigerLTW02-45Light.2... woff2 swap

Size 26 KB

Load time 729 ms

Start 4.3 s

Risk FOUT — text flashes from fallback to web font

FrutigerLTW02-65Bold.ed... woff2 swap

Size 23 KB

Load time 1.0 s

Start 4.3 s

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

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

4 hints, 0 missing preconnects

PASS

4 hints, 0 missing preconnects

Page uses 4 resource hint(s)

Current Resource Hints

preconnect

—

preload

dns-prefetch

—

prefetch

—

4 resource hints configured

A+

Render-Blocking Resources

No render-blocking resources detected

PASS

No render-blocking resources detected

No render-blocking resources detected in <head>

A+

Third-Party Resources

No third-party resources detected

PASS

No third-party resources detected

Network Waterfall

34 requests over 8874ms

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 5089ms · 1466KB · €55/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
www.dlr.de www.dlr.de	Other	2400ms	1051 KB	59%	€26/mo	Costly
www.dlr.de www.dlr.de	Other	1722ms	132 KB	—	€19/mo	Costly
Unattributable Unattributable	Other	642ms	0 KB	—	€7/mo	Costly
www.dlr.de www.dlr.de	Other	271ms	261 KB	—	€3/mo	Costly
www.dlr.de www.dlr.de	Other	54ms	22 KB	—	€1/mo	Optional

www.dlr.de

Other

Costly

Execution 2400ms

Transfer 1051 KB

Unused 59%

Monthly Cost €26/mo

www.dlr.de

Other

Costly

Execution 1722ms

Transfer 132 KB

Monthly Cost €19/mo

Unattributable

Other

Costly

Execution 642ms

Transfer 0 KB

Monthly Cost €7/mo

www.dlr.de

Other

Costly

Execution 271ms

Transfer 261 KB

Monthly Cost €3/mo

www.dlr.de

Other

Optional

Execution 54ms

Transfer 22 KB

Monthly Cost €1/mo

These scripts may cost more than they're worth

www.dlr.de adds 2400ms and costs ~€26/month
www.dlr.de adds 1722ms and costs ~€19/month
Unattributable adds 642ms and costs ~€7/month
www.dlr.de adds 271ms and costs ~€3/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.dlr.de takes 2400ms 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

59% of www.dlr.de's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

www.dlr.de takes 1722ms 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 642ms 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

www.dlr.de takes 271ms 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.