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https://vdwoude.eu

Performance

· 21 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
90
GRADE
A
FIX
2
REVIEW
6
PASS
11
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

99
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
84
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
81
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

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

689 ms

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

800 ms

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.

0.035

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

689 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

800 ms

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
21
11 PASS 6 REVIEW 2 FIX
D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (455.8 KiB of 456.0 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
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.

C
Image Optimization
Action
15 images, 0 KB saveable
REVIEW
15 images, 0 KB saveable
Warning::
https://www.vdwoude.eu/leidraad/leidraad.jpg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/asl-logo.jpg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/hwe-klein.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/cor.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/gps-logo.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/pc2-nl-25.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/vganwb-web.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/bbclone.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/ecs-logo.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/ew-logo.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/leidraad/ud_00.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/stb-vdw-klein.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/pc3-nl-30.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.vdwoude.eu/authy/images/cz-logo.jpg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
15 images 452 KB
0 oversized -0 KB
15 legacy format
14 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

B
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
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.
C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
B
Main HTML Cache-Control
No Cache-Control header on main HTML response
REVIEW
No Cache-Control header on main HTML response
Info::
Main HTML response has no Cache-Control header
Without an explicit Cache-Control, browsers fall back to heuristic caching (~10% of Last-Modified age). Set `Cache-Control: no-cache` or `max-age=300` for HTML to control freshness explicitly -- prevents stale auth state and SPA shell drift.
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
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.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Page Weight Budget
456 KB transferred, 20 requests
PASS
456 KB transferred, 20 requests
Info::
Page weighs 458 KB (456 KB transferred)
Info::
20 HTTP requests
Info::
Estimated 0.09 g CO2 per page load
456 KB / 2.4 MB budget
456 KB transferred
20 requests
0.09 g CO2 per page load
Images 451.8 KiB 99%
Other 1.6 KiB 0%
HTML 1.5 KiB 0%
CSS 1017 B 0%
0 2.4 MB 4.9 MB
Under budget
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
JS Execution Cost
No JS execution data
PASS
No JS execution data
Info::
No significant JS execution detected

Main Thread Breakdown

Other 51% Style & Layout 35% Rendering 7% Script Evaluation 3%
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
A+
JS Bundles
No JavaScript
PASS
No JavaScript
Info::
No JavaScript bundles
No JavaScript files loaded.
A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
LCP image preload audit not available for this scan
A+
Server Response Intelligence
1 server-response signal(s) detected
PASS
1 server-response signal(s) detected
Info::
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
20 resources · 456 KB · 0 KB savings available
PASS
20 resources · 456 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 456 KB
Warning::
19 third-party resources (100% of weight)
20 resources · 456.0 KiB · 19 third-party Within 1MB page-weight target
Image 99% · 453.3 KiB
Document 0% · 1.6 KiB
CSS 0% · 1017 B
Other 0% · 0 B
Network Waterfall
20 requests over 425ms
INFO
0 ms 200 ms 400 ms 600 ms 800 ms FCP 689 ms LCP 800 mshttps://vdwoude.eu// https://vdwoude.eu/ — 301 — 117 B — 90 ms — h2http://www.vdwoude.eu/www.vdwoude.eu/ http://www.vdwoude.eu/ — 307 — 0 B — 1 ms — http/1.1https://www.vdwoude.eu/www.vdwoude.eu/ https://www.vdwoude.eu/ — 200 — 1.5 KiB — 116 ms — h2https://www.vdwoude.eu/authy/styles/screen.csswww.vdwoude.eu/authy/styles/screen.... https://www.vdwoude.eu/authy/styles/screen.css — 200 — 1017 B — 93 ms — h2https://www.vdwoude.eu/authy/images/stb-vdw-klein.jpgwww.vdwoude.eu/authy/images/stb-vdw... https://www.vdwoude.eu/authy/images/stb-vdw-klein.jpg — 200 — 26.2 KiB — 66 ms — h2https://www.vdwoude.eu/authy/images/vganwb-web.svgwww.vdwoude.eu/authy/images/vganwb-... https://www.vdwoude.eu/authy/images/vganwb-web.svg — 200 — 3.2 KiB — 66 ms — h2https://www.vdwoude.eu/authy/images/pc3-nl-30.pngwww.vdwoude.eu/authy/images/pc3-nl-... https://www.vdwoude.eu/authy/images/pc3-nl-30.png — 200 — 41.1 KiB — 86 ms — h2https://www.vdwoude.eu/authy/images/cor.pngwww.vdwoude.eu/authy/images/cor.png https://www.vdwoude.eu/authy/images/cor.png — 200 — 122.9 KiB — 137 ms — h2https://www.vdwoude.eu/authy/images/cz-logo.jpgwww.vdwoude.eu/authy/images/cz-logo... https://www.vdwoude.eu/authy/images/cz-logo.jpg — 200 — 24.7 KiB — 119 ms — h2https://www.vdwoude.eu/authy/images/bbclone.pngwww.vdwoude.eu/authy/images/bbclone... https://www.vdwoude.eu/authy/images/bbclone.png — 200 — 5.9 KiB — 109 ms — h2https://www.vdwoude.eu/authy/images/gps-logo.pngwww.vdwoude.eu/authy/images/gps-log... https://www.vdwoude.eu/authy/images/gps-logo.png — 200 — 33.3 KiB — 127 ms — h2https://www.vdwoude.eu/leidraad/leidraad.jpgwww.vdwoude.eu/leidraad/leidraad.jp... https://www.vdwoude.eu/leidraad/leidraad.jpg — 200 — 39.0 KiB — 127 ms — h2https://www.vdwoude.eu/authy/images/ew-logo.pngwww.vdwoude.eu/authy/images/ew-logo... https://www.vdwoude.eu/authy/images/ew-logo.png — 200 — 25.4 KiB — 128 ms — h2https://www.vdwoude.eu/leidraad/ud_00.pngwww.vdwoude.eu/leidraad/ud_00.png https://www.vdwoude.eu/leidraad/ud_00.png — 200 — 26.8 KiB — 129 ms — h2https://www.vdwoude.eu/authy/images/ecs-logo.pngwww.vdwoude.eu/authy/images/ecs-log... https://www.vdwoude.eu/authy/images/ecs-logo.png — 200 — 10.2 KiB — 134 ms — h2https://www.vdwoude.eu/authy/images/pc2-nl-25.pngwww.vdwoude.eu/authy/images/pc2-nl-... https://www.vdwoude.eu/authy/images/pc2-nl-25.png — 200 — 35.7 KiB — 135 ms — h2https://www.vdwoude.eu/authy/images/asl-logo.jpgwww.vdwoude.eu/authy/images/asl-log... https://www.vdwoude.eu/authy/images/asl-logo.jpg — 200 — 33.5 KiB — 151 ms — h2https://www.vdwoude.eu/authy/images/hwe-klein.pngwww.vdwoude.eu/authy/images/hwe-kle... https://www.vdwoude.eu/authy/images/hwe-klein.png — 200 — 23.0 KiB — 152 ms — h2https://www.vdwoude.eu/authy/images/bg-geel.gifwww.vdwoude.eu/authy/images/bg-geel... https://www.vdwoude.eu/authy/images/bg-geel.gif — 200 — 848 B — 65 ms — h2https://www.vdwoude.eu/authy/images/favicon.icowww.vdwoude.eu/authy/images/favicon... https://www.vdwoude.eu/authy/images/favicon.ico — 200 — 1.5 KiB — 37 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Image Optimization
15 images, 475 KB total, 310 KB wasted
INFO

Image Optimization Audit

Total Images

15

Total Size

475 KB

Oversized

12

Wasted

310 KB

15 missing alt text 15 missing dimensions 5 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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