Performance

· 26 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.

3.93 s

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

4.45 s

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

40 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.

5.28 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.

4.47 s

Page Load Progression

378 ms

756 ms

1.1 s

1.5 s

1.9 s

2.3 s

2.6 s

3.0 s

Checks

16 PASS 8 REVIEW

JS Execution Cost

Action

1071ms total JS execution

REVIEW

1071ms total JS execution

https://website-laten-maken.nl/: 444ms CPU time

https://website-laten-maken.nl/assets/index-CVPqMd...: 343ms CPU time

Unattributable: 284ms CPU time

Main Thread Breakdown

Other 33% Script Evaluation 31% Style & Layout 28% Rendering 4% Parse HTML & CSS 3%

Script	Total	Scripting	Parse/Compile	Party
https://website-laten-maken.nl/	444ms	17ms	9ms	1st
https://website-laten-maken.nl/assets/index-CVPqMdnZ.js	343ms	307ms	3ms	1st
Unattributable	284ms	6ms	0ms	1st

JS Bundles

52 scripts, 119 KB unused

REVIEW

52 scripts, 119 KB unused

https://website-laten-maken.nl/assets/index-CVPqMd...: 96 KB unused (62%)

Consider code splitting or tree shaking to reduce unused code.

https://website-laten-maken.nl/assets/primitives-D...: 23 KB unused (83%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 119 KB

119 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://website-laten-maken.nl/assets/index-CVPqMdnZ.js	155 KB	96 KB (62%)	✓	1st
https://website-laten-maken.nl/assets/primitives-D8Szdeug.js	28 KB	23 KB (83%)	✓	1st
https://website-laten-maken.nl/assets/jsx-runtime-Cltr0gcK.js	3 KB	—	✓	1st
https://website-laten-maken.nl/assets/createServerFn-Bk23-1SV.js	12 KB	—	✓	1st
https://website-laten-maken.nl/assets/not-found-i5RsCZif.js	0 KB	—	✓	1st
https://website-laten-maken.nl/assets/invariant-CgFvOqN2.js	0 KB	—	✓	1st
https://website-laten-maken.nl/assets/link-D4iki_Ag.js	4 KB	—	✓	1st
https://website-laten-maken.nl/assets/matchContext-D7fiU5TJ.js	0 KB	—	✓	1st
https://website-laten-maken.nl/assets/route-BzDGWjIx.js	1 KB	—	✓	1st
https://website-laten-maken.nl/assets/preload-helper-Du08JocR.js	1 KB	—	✓	1st

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

HTTP/3 (QUIC)

HTTP/3 not advertised

REVIEW

HTTP/3 not advertised

HTTP/3 (QUIC) is not advertised

HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.

Document Compression

Document response uses gzip; brotli would be ~20% smaller

REVIEW

Document response uses gzip; brotli would be ~20% smaller

Main HTML response uses gzip (brotli would be ~20% smaller)

All current browsers support brotli. Most CDNs (Cloudflare, Fastly, AWS CloudFront, Vercel, Netlify) can switch from gzip to brotli with a single config flag. Origin servers (nginx, Apache) need a brotli module compiled in -- nginx-brotli or Apache mod_brotli.

Asset Compression

1 of 1 asset host serve text uncompressed

REVIEW

1 of 1 asset host serve text uncompressed

fonts.googleapis.com serves text assets uncompressed (assets: 4)

The sampled response carries a text content type but no Content-Encoding, so the bytes go over the wire raw. Text compression typically removes 70-80% of a JS or CSS payload -- this is the single cheapest transfer win available on this host.

Got: fonts.googleapis.com (text/css)

Server-Timing Observability

No Server-Timing header found

REVIEW

No Server-Timing header found

Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

HTTP Caching

no-cache, must-revalidate, max-age=0

REVIEW

no-cache, must-revalidate, max-age=0

Cache-Control header is set

Got: no-cache, must-revalidate, max-age=0

No ETag or Last-Modified header

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

Cache-Control

no-cache, must-revalidate, max-age=0

Directive	Value	Meaning
no-cache	—	Cache but always revalidate first
must-revalidate	—	Must recheck with server after expiry
max-age	0	Cache for 0 seconds

A+

Page Weight Budget

540 KB transferred, 65 requests

PASS

540 KB transferred, 65 requests

Page weighs 1.4 MB (540 KB transferred)

65 HTTP requests

Estimated 0.11 g CO2 per page load

540 KB transferred

65 requests

0.11 g CO2 per page load

JavaScript 309.5 KiB 57%

Images 139.0 KiB 26%

CSS 47.2 KiB 9%

Fonts 23.9 KiB 4%

HTML 11.4 KiB 2%

Other 8.2 KiB 2%

Other 698 B 0%

Other 181 B 0%

Other 83 B 0%

0 2.4 MB 4.9 MB

Under budget

A+

Third-Party Impact

5% third-party, 0 ms blocking

PASS

5% third-party, 0 ms blocking

Third-party code accounts for 5% of page weight (27.4 KiB of 540.1 KiB)

Third-party blocking time is low (0 ms)

95%

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+

Image Optimization

2 images, 0 KB saveable

PASS

2 images, 0 KB saveable

All images are well-optimized

2 images 139 KB

0 oversized -0 KB

0 legacy format

0 missing dimensions CLS risk

A+

Font Loading

1 fonts (24 KB)

PASS

1 fonts (24 KB)

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

Web fonts

24 KB total

Render-blocking

of 1

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

xn7gYHE41ni1AdIRggexSvf... woff2 swap

Size 24 KB

Load time 22 ms

Start 714 ms

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

3 hints, 0 missing preconnects

PASS

3 hints, 0 missing preconnects

Page uses 3 resource hint(s)

Current Resource Hints

preconnect

preload

dns-prefetch

—

prefetch

—

3 resource hints configured

A+

LCP Image Preload

LCP preload audit not available

PASS

LCP preload audit not available

LCP image preload audit not available for this scan

A+

Main HTML Cache-Control

Main HTML uses no-cache -- safe revalidate-on-request policy

PASS

Main HTML uses no-cache -- safe revalidate-on-request policy

Got: no-cache, must-revalidate, max-age=0

Server Response Intelligence

2 server-response signal(s) detected

PASS

2 server-response signal(s) detected

Compressed response missing `Vary` header

The page is served with `Content-Encoding: gzip` but has no `Vary` header. Without `Vary: Accept-Encoding`, intermediary caches (corporate proxies, ISP caches) may serve the compressed variant to clients that didn't send the matching `Accept-Encoding` -- the client sees garbled bytes. Add `Vary: Accept-Encoding` whenever the response is conditionally compressed.

No `ETag` or `Last-Modified` -- conditional GET not supported

Without either header, browsers can't issue conditional GETs and refresh always re-downloads the full response body even when nothing changed. Add `ETag: "<hash>"` (or `Last-Modified: <date>`) on cacheable responses; the server returns 304 Not Modified when the client's cached copy is still valid, saving bandwidth.

A+

Page Weight Inventory

65 resources · 540 KB · 119 KB savings available

PASS

65 resources · 540 KB · 119 KB savings available

Within 1MB page-weight target

Got: 540 KB

~119 KB of savings available

3 third-party resources (5% of weight)

65 resources · 540.1 KiB · 3 third-party Within 1MB page-weight target

JavaScript 57% · 309.5 KiB

Image 27% · 147.2 KiB

CSS 9% · 47.2 KiB

Font 4% · 23.9 KiB

Document 2% · 11.4 KiB

Other 0% · 962 B

~119.3 KiB of savings available

Remove unused JavaScript: 119.3 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

65 resources			540.1 KiB

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

A+

JavaScript Blocking

No render-blocking JS or document.write usage detected

PASS

No render-blocking JS or document.write usage detected

No JavaScript blocking issues detected

A+

CSS Performance Depth

No CSS performance depth issues detected

PASS

No CSS performance depth issues detected

Network Waterfall

65 requests over 2852ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Image Optimization

7 images, 423 KB total, 127 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

423 KB

Oversized

Wasted

127 KB

7 missing dimensions 2 missing lazy loading

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.