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

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.

2.68 s

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

6.42 s

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

193 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.022

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

4.52 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.

6.76 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 7 REVIEW 1 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 (1.4 MiB of 1.4 MiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

Page Weight Budget

1.4 MB transferred, 45 requests

REVIEW

1.4 MB transferred, 45 requests

Page weighs 2.4 MB (1.4 MB transferred)

45 HTTP requests

Estimated 0.29 g CO2 per page load

1.4 MB transferred

45 requests

0.29 g CO2 per page load

Images 993.7 KiB 70%

JavaScript 193.6 KiB 14%

Fonts 177.1 KiB 12%

CSS 35.8 KiB 3%

HTML 15.9 KiB 1%

Other 1.3 KiB 0%

Other 324 B 0%

0 2.4 MB 4.9 MB

Under budget

Image Optimization

33 images, 0 KB saveable

REVIEW

33 images, 0 KB saveable

is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

33 images 994 KB

0 oversized -0 KB

17 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

Action

1564ms total JS execution

REVIEW

1564ms total JS execution

https://www.umu.se/: 602ms CPU time

Unattributable: 402ms CPU time

https://www.umu.se/Static/umu.js?v=52493967: 365ms CPU time

https://matomo.analys.cloud/js/container_ihGxGRPo....: 133ms CPU time

https://www.umu.se/Static/klaro_v0.7.22_no_css.js: 62ms CPU time

Third-party scripts: 1564ms (100% of total)

Main Thread Breakdown

Other 32% Script Evaluation 29% Style & Layout 21% Rendering 8% Script Parsing & Compilation 7% Parse HTML & CSS 4%

Script	Total	Scripting	Parse/Compile	Party
https://www.umu.se/	602ms	28ms	7ms	3rd
Unattributable	402ms	16ms	0ms	3rd
https://www.umu.se/Static/umu.js?v=52493967	365ms	272ms	56ms	3rd
https://matomo.analys.cloud/js/container_ihGxGRPo.js	133ms	90ms	41ms	3rd
https://www.umu.se/Static/klaro_v0.7.22_no_css.js	62ms	49ms	12ms	3rd

JS Bundles

4 scripts, 106 KB unused

REVIEW

4 scripts, 106 KB unused

https://www.umu.se/Static/umu.js?v=52493967: 62 KB unused (66%)

Consider code splitting or tree shaking to reduce unused code.

https://matomo.analys.cloud/js/container_ihGxGRPo....: 44 KB unused (56%)

Consider code splitting or tree shaking to reduce unused code.

https://www.umu.se/Static/klaro_v0.7.22_no_css.js: unminified — 3 KB could be saved

Total unused JavaScript: 106 KB

106 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.umu.se/Static/umu.js?v=52493967	93 KB	62 KB (66%)	✓	3rd
https://matomo.analys.cloud/js/container_ihGxGRPo.js	79 KB	44 KB (56%)	✓	3rd
https://www.umu.se/Static/klaro_v0.7.22_no_css.js	21 KB	—	✗	3rd
https://matomo.analys.cloud/plugins/HeatmapSessionRecording/configs.php?idsite=24&trackerid=wgy2Rb&url=https%3A%2F%2Fwww.umu.se%2F	0 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

45 resources · 1.4 MB · 106 KB savings available

REVIEW

45 resources · 1.4 MB · 106 KB savings available

Page weight 394 KB over 1MB target

Got: 1.4 MB Expected: ≤ 1 MB

~106 KB of savings available

44 third-party resources (100% of weight)

45 resources · 1.4 MiB · 44 third-party 393.7 KiB over 1MB target

Image 70% · 995.0 KiB

JavaScript 14% · 193.6 KiB

Font 12% · 177.1 KiB

CSS 3% · 35.8 KiB

Document 1% · 15.9 KiB

Other 0% · 380 B

~105.8 KiB of savings available

Remove unused JavaScript: 105.8 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

45 resources			1.4 MiB

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

HTTP Caching

no-cache

REVIEW

no-cache

Cache-Control header is set

Got: no-cache

No ETag or Last-Modified header

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

Cache-Control

no-cache

Directive	Value	Meaning
no-cache	—	Cache but always revalidate first

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 (177 KB)

PASS

3 fonts (177 KB)

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

Web fonts

177 KB total

Render-blocking

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

GothamSSm-Book_Web.woff2 woff2 swap

Size 59 KB

Load time 643 ms

Start 1.2 s

Risk FOUT — text flashes from fallback to web font

GothamSSm-Bold_Web.woff2 woff2 swap

Size 59 KB

Load time 766 ms

Start 1.2 s

Risk FOUT — text flashes from fallback to web font

GothamSSm-Medium_Web.woff2 woff2 swap

Size 59 KB

Load time 829 ms

Start 1.2 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

10 hints, 0 missing preconnects

PASS

10 hints, 0 missing preconnects

Page uses 10 resource hint(s)

Current Resource Hints

preconnect

—

preload

dns-prefetch

—

prefetch

—

10 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

45 requests over 3353ms

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 1564ms · 209KB · kr170/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
www.umu.se www.umu.se	Other	602ms	16 KB	—	kr65/mo	Costly
Unattributable Unattributable	Other	402ms	0 KB	—	kr44/mo	Costly
www.umu.se www.umu.se	Other	365ms	93 KB	66%	kr40/mo	Costly
Matomo matomo.analys.cloud	Analytics	133ms	79 KB	56%	kr14/mo	Optional
www.umu.se www.umu.se	Other	62ms	21 KB	—	kr7/mo	Optional

www.umu.se

Other

Costly

Execution 602ms

Transfer 16 KB

Monthly Cost kr65/mo

Unattributable

Other

Costly

Execution 402ms

Transfer 0 KB

Monthly Cost kr44/mo

www.umu.se

Other

Costly

Execution 365ms

Transfer 93 KB

Unused 66%

Monthly Cost kr40/mo

Matomo

Analytics

Optional

Execution 133ms

Transfer 79 KB

Unused 56%

Monthly Cost kr14/mo

www.umu.se

Other

Optional

Execution 62ms

Transfer 21 KB

Monthly Cost kr7/mo

These scripts may cost more than they're worth

www.umu.se adds 602ms and costs ~kr65/month
Unattributable adds 402ms and costs ~kr44/month
www.umu.se adds 365ms and costs ~kr40/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.umu.se takes 602ms 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 402ms 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.umu.se takes 365ms 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

66% of www.umu.se'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

56% of Matomo'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

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.