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.

1.01 s

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

1.63 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.

0.042

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

1.32 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.

1.63 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

5 PASS 6 REVIEW 2 FIX

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 (1.2 MiB of 1.2 MiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

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.

Page Weight Budget

1.2 MB transferred, 56 requests

REVIEW

1.2 MB transferred, 56 requests

Page weighs 2.7 MB (1.2 MB transferred)

Fonts are 253 KB — consider subsetting or using system fonts

Subset fonts to include only used characters, or switch to system font stacks.

Got: 253 KB

56 HTTP requests

Estimated 0.26 g CO2 per page load

1.2 MB transferred

56 requests

0.26 g CO2 per page load

Images 494.3 KiB 39%

JavaScript 280.1 KiB 22%

Fonts 253.1 KiB 20%

CSS 108.6 KiB 9%

HTML 98.4 KiB 8%

Other 34.8 KiB 3%

Other 4.9 KiB 0%

Other 746 B 0%

Other 115 B 0%

Other 0 B 0%

0 2.4 MB 4.9 MB

Under budget

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

Image Optimization

27 images, 0 KB saveable

REVIEW

27 images, 0 KB saveable

is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

27 images 494 KB

0 oversized -0 KB

9 legacy format

1 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

JS Execution Cost

588ms total JS execution

REVIEW

588ms total JS execution

https://www.mpg.de/de: 382ms CPU time

Unattributable: 116ms CPU time

https://www.mpg.de/assets/mpg_fouc-ee7a69a330deff3...: 90ms CPU time

Third-party scripts: 588ms (100% of total)

Main Thread Breakdown

Style & Layout 32% Other 31% Script Evaluation 20% Rendering 10% Parse HTML & CSS 4% Script Parsing & Compilation 3%

Script	Total	Scripting	Parse/Compile	Party
https://www.mpg.de/de	382ms	16ms	1ms	3rd
Unattributable	116ms	10ms	0ms	3rd
https://www.mpg.de/assets/mpg_fouc-ee7a69a330deff3ef667e094d19ecd86005d5c4d489ec05bb494fc8ec13822ca.js	90ms	50ms	1ms	3rd

JS Bundles

11 scripts, 117 KB unused

REVIEW

11 scripts, 117 KB unused

https://www.mpg.de/assets/mpg_base-9108b3aa613f455...: 41 KB unused (50%)

Consider code splitting or tree shaking to reduce unused code.

https://statistik.mpg.de/api.js: 40 KB unused (61%)

Consider code splitting or tree shaking to reduce unused code.

https://web.cmp.usercentrics.eu/ui/v/3.116.0/WebSd...: 36 KB unused (64%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 117 KB

117 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.mpg.de/assets/mpg_base-9108b3aa613f4551f661af067a1cc41438d882db9354b1c9c1bd297da3437075.js	82 KB	41 KB (50%)	✓	3rd
https://statistik.mpg.de/api.js	66 KB	40 KB (61%)	✓	3rd
https://web.cmp.usercentrics.eu/ui/v/3.116.0/WebSdk.lib.d00a93b7.js	56 KB	36 KB (64%)	✓	3rd
https://web.cmp.usercentrics.eu/ui/loader.js	15 KB	—	✓	3rd
https://web.cmp.usercentrics.eu/ui/v/3.116.0/GdprCmpController.c4576b71.js	9 KB	—	✓	3rd
https://www.mpg.de/assets/mpg_fouc-ee7a69a330deff3ef667e094d19ecd86005d5c4d489ec05bb494fc8ec13822ca.js	21 KB	—	✓	3rd
https://www.mpg.de/assets/mpg_amd-96c495d5160c48fc3a73f7ff6a63535941287dc0606ebb2b051b36b7f28e05e5.js	9 KB	—	✓	3rd
https://www.mpg.de/assets/mpg_amd_bundle-f4f11cbae10efc141acad56a485e14509ad514690b8af87326fedaa6bab92f28.js	5 KB	—	✓	3rd
https://www.mpg.de/assets/responsive/live/tabcard-e851b31a4771a2bb98458d8eec5f67d99c73a82d304902929eb3556f77fd63f9.js	13 KB	—	✓	3rd
https://www.mpg.de/assets/responsive/mpg_common/live/intersection-observer-2604760b7ed90cc98fd55be52dbeba2daa84985bbe92dfdf5ff61bf252586783.js	3 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

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

56 resources · 1.2 MB · 117 KB savings available

REVIEW

56 resources · 1.2 MB · 117 KB savings available

Page weight 251 KB over 1MB target

Got: 1.2 MB Expected: ≤ 1 MB

~117 KB of savings available

55 third-party resources (100% of weight)

56 resources · 1.2 MiB · 55 third-party 251.0 KiB over 1MB target

Image 41% · 528.2 KiB

JavaScript 22% · 280.1 KiB

Font 20% · 253.1 KiB

CSS 9% · 108.6 KiB

Document 8% · 99.1 KiB

Other 0% · 6.0 KiB

~116.6 KiB of savings available

Remove unused JavaScript: 116.6 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

56 resources			1.2 MiB

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

6 fonts (253 KB)

PASS

6 fonts (253 KB)

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

Web fonts

253 KB total

Render-blocking

of 6

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

roboto-v20-latin-ext_la... woff2 swap

Size 50 KB

Load time 365 ms

Start 396 ms