https://www.middelburg.nl
Performance
· 28 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.SCORE
82
GRADE
B
FIX
3
REVIEW
8
PASS
13
INFO
4
Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
23
96
92
100
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
6.21 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
11.94 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
515 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.843
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.21 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.
12.49 s
Page Load Progression
Checks
2813 PASS 8 REVIEW 3 FIX
DThird-Party ImpactAction89% third-party, 0 ms blockingFIX
Third-Party Impact
Action89% third-party, 0 ms blocking
89% third-party, 0 ms blocking
Warning::
Third-party code accounts for 89% of page weight (1.7 MiB of 2.0 MiB)
Info::
Third-party blocking time is low (0 ms)
89%
First-party Third-party
DJS Execution CostAction2858ms total JS executionFIX
JS Execution Cost
Action2858ms total JS execution
2858ms total JS execution
Warning::
https://www.middelburg.nl/: 1041ms CPU time
Warning::
Unattributable: 722ms CPU time
Warning::
https://cuatro.sim-cdn.nl/assets/2.14.0/_next/stat...: 555ms CPU time
Info::
https://cuatro.sim-cdn.nl/assets/2.14.0/_next/stat...: 191ms CPU time
Info::
https://cuatro.sim-cdn.nl/assets/2.14.0/_next/stat...: 165ms CPU time
Info::
Third-party scripts: 1095ms (38% of total)
Main Thread Breakdown
Script Evaluation 34% Style & Layout 32% Other 21% Script Parsing & Compilation 5% Parse HTML & CSS 4% Garbage Collection 4%
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.middelburg.nl/ | 1041ms | 4ms | 2ms | 1st |
| Unattributable | 722ms | 19ms | 0ms | 1st |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/21-1lnek6vezq.js | 555ms | 485ms | 15ms | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/turbopack-2ro3tmdn33ah0.js | 191ms | 189ms | 1ms | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/453vyw5pupwi9.js | 165ms | 154ms | 11ms | 3rd |
| https://middelburg.logging.simanalytics.nl/piwik.js | 76ms | 38ms | 12ms | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/15alwlali9vhj.js | 55ms | 38ms | 1ms | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/3f1_vemy1kcvj.js | 53ms | 42ms | 8ms | 3rd |
DPage Weight InventoryAction524 resources · 2.0 MB · 187 KB savings availableFIX
Page Weight Inventory
Action524 resources · 2.0 MB · 187 KB savings available
524 resources · 2.0 MB · 187 KB savings available
Warning::
Page weight 2.0 MB exceeds 1 MB target by 981 KB
Got: 2.0 MB Expected: ≤ 1 MB
Info::
~187 KB of savings available
Warning::
69 third-party resources (89% of weight)
Info::
1 resources over 200KB
524 resources · 2.0 MiB · 69 third-party 980.8 KiB over 1MB target
JavaScript 35% · 691.8 KiB
Image 30% · 599.4 KiB
Font 18% · 351.8 KiB
Other 9% · 176.9 KiB
CSS 7% · 131.4 KiB
Document 3% · 53.6 KiB
~186.6 KiB of savings available
Remove unused JavaScript: 186.6 KiB
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 524 resources | 2.0 MiB | ||||||
CPage Weight BudgetAction2.0 MB transferred, 524 requestsREVIEW
Page Weight Budget
Action2.0 MB transferred, 524 requests
2.0 MB transferred, 524 requests
Info::
Page weighs 4.5 MB (2.0 MB transferred)
Warning::
JavaScript is 691 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 691 KB
Info::
Fonts are 352 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 352 KB
Warning::
524 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.41 g CO2 per page load
2.0 MB transferred
524 requests
0.41 g CO2 per page load
JavaScript 690.8 KiB 34%
Images 597.1 KiB 30%
Fonts 351.8 KiB 18%
Other 139.7 KiB 7%
CSS 131.4 KiB 7%
Other 52.5 KiB 3%
HTML 39.9 KiB 2%
Other 1.5 KiB 0%
Other 229 B 0%
0 2.4 MB 4.9 MB
Approaching limit
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
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
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Why this matters
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
BImage Optimization6 images, 0 KB saveableREVIEW
Image Optimization
6 images, 0 KB saveable
6 images, 0 KB saveable
Info::
All images are well-optimized
6 images 597 KB
0 oversized -0 KB
6 legacy format
0 missing dimensions CLS risk
CJS BundlesAction41 scripts, 187 KB unusedREVIEW
JS Bundles
Action41 scripts, 187 KB unused
41 scripts, 187 KB unused
Warning::
https://middelburg.logging.simanalytics.nl/piwik.j...: 85 KB unused (63%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cuatro.sim-cdn.nl/assets/2.14.0/_next/stat...: 50 KB unused (88%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cuatro.sim-cdn.nl/assets/2.14.0/_next/stat...: 29 KB unused (43%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cuatro.sim-cdn.nl/assets/2.14.0/_next/stat...: 23 KB unused (35%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 187 KB
187 KB unused JavaScript
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://middelburg.logging.simanalytics.nl/piwik.js | 134 KB | 85 KB (63%) | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/3t-fp4k4vnpbe.js | 57 KB | 50 KB (88%) | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/453vyw5pupwi9.js | 68 KB | 29 KB (43%) | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/21-1lnek6vezq.js | 67 KB | 23 KB (35%) | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/34kog4seun0vk.js | 2 KB | — | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/1eqhzl0-k473i.js | 8 KB | — | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/3l648yjn6i3g2.js | 3 KB | — | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/2pp0lcrkgfaxj.js | 12 KB | — | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/18n-aizvfnrqo.js | 9 KB | — | ✓ | 3rd |
| https://cuatro.sim-cdn.nl/assets/2.14.0/_next/static/chunks/1vggu62g791zq.js | 9 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
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
BHTTP/3 (QUIC)HTTP/3 not advertisedREVIEW
HTTP/3 (QUIC)
HTTP/3 not advertised
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.
BDocument CompressionDocument response uses gzip; brotli would be ~20% smallerREVIEW
Document Compression
Document response uses gzip; brotli would be ~20% smaller
Document response uses gzip; brotli would be ~20% smaller
Info::
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.
CAsset CompressionAction1 of 3 asset hosts serve text uncompressedREVIEW
Asset Compression
Action1 of 3 asset hosts serve text uncompressed
1 of 3 asset hosts serve text uncompressed
Info::
cuatro.sim-cdn.nl serves assets with brotli (assets: 66)
Got: cuatro.sim-cdn.nl (text/css)
Info::
cdn-eu.readspeaker.com serves assets with gzip; brotli would be ~20% smaller (assets: 3)
Every current browser accepts brotli. On a CDN this is a per-pull-zone toggle (Cloudflare, Fastly, CloudFront, CDN77, Bunny all expose it); on an origin it needs the brotli module (nginx-brotli, Apache mod_brotli). The saving lands on the assets this host serves, not on the HTML document -- the document's own encoding is reported separately.
Got: cdn-eu.readspeaker.com (text/css)
Warning::
middelburg.logging.simanalytics.nl serves text assets uncompressed (assets: 3)
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: middelburg.logging.simanalytics.nl (application/javascript)
BServer-Timing ObservabilityNo Server-Timing header foundREVIEW
Server-Timing Observability
No Server-Timing header found
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.
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
ActionWhether the site is served from green-energy infrastructure
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
Text Compression
All text resources are compressed
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+Font Loading6 fonts (352 KB)PASS
Font Loading
6 fonts (352 KB)
6 fonts (352 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
6
352 KB total
Render-blocking
0
of 6
Dominant font-display
swap
Most common across fonts
Font loading timeline
Transfer FOIT (block) FOUT (swap)
latin-400-normal.woff2 woff2 swap
Size 22 KB
Load time 90 ms
Start 484 ms
Risk FOUT — text flashes from fallback to web font
fa-solid-900.woff2 woff2 swap
Size 155 KB
Load time 19 ms
Start 485 ms
Risk FOUT — text flashes from fallback to web font
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
latin-300-normal.woff2 woff2 swap
Size 22 KB
Load time 92 ms
Start 485 ms
Risk FOUT — text flashes from fallback to web font
OpenGemeenten.woff2 woff2 swap
Size 26 KB
Load time 13 ms
Start 485 ms
Risk FOUT — text flashes from fallback to web font
toptaken01.woff2 woff2 swap
Size 10 KB
Load time 13 ms
Start 485 ms
Risk FOUT — text flashes from fallback to web font
fa-brands-400.woff2 woff2 swap
Size 116 KB
Load time 19 ms
Start 485 ms
Risk FOUT — text flashes from fallback to web font
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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)
Fixing the unchecked items could save ~136 KB and ~272 ms
A+Resource CachingAll resources properly cachedPASS
Resource Caching
All resources properly cached
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+Critical Rendering PathNo render-blocking resourcesPASS
Critical Rendering Path
No render-blocking resources
No render-blocking resources
Info::
No render-blocking resources detected
A+Resource Hints7 hints, 0 missing preconnectsPASS
Resource Hints
7 hints, 0 missing preconnects
7 hints, 0 missing preconnects
Info::
Page uses 7 resource hint(s)
Current Resource Hints
preconnect—
preload 6
dns-prefetch—
prefetch 1
7 resource hints configured
A+LCP Image PreloadLCP preload audit not availablePASS
LCP Image Preload
LCP preload audit not available
LCP preload audit not available
Info::
LCP image preload audit not available for this scan
A+Main HTML Cache-ControlMain HTML max-age=30 (≤ 5min) is appropriatePASS
Main HTML Cache-Control
Main HTML max-age=30 (≤ 5min) is appropriate
Main HTML max-age=30 (≤ 5min) is appropriate
Info::
Main HTML max-age=30 (≤ 5min) is appropriate
Got: public, s-maxage=60, max-age=30, stale-while-revalidate=59
A+Server Response Intelligence2 server-response signal(s) detectedPASS
Server Response Intelligence
2 server-response signal(s) detected
2 server-response signal(s) detected
Info::
`Vary` header declared: Accept-Encoding
The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).
Info::
`ETag` present -- conditional GET supported
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
Render-Blocking Resources
No render-blocking resources detected
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+Third-Party ResourcesNo third-party resources detectedPASS
Third-Party Resources
No third-party resources detected
No third-party resources detected
AJavaScript Blocking1 JS blocking issue(s) detectedPASS
JavaScript Blocking
1 JS blocking issue(s) detected
1 JS blocking issue(s) detected
Warning::
1 render-blocking <script src> tag(s) without async/defer
Each `<script src=...>` without `async`, `defer`, or `type="module"` blocks HTML parsing while the browser fetches and executes it. The block lasts the entire round-trip + execution time -- on slow networks this translates directly into LCP delay. Add `defer` (executes after parse, in source order) for scripts that interact with the DOM, or `async` (executes whenever ready) for analytics / independent scripts. Module scripts (`type="module"`) are deferred by default.
ACSS Performance Depth1 CSS depth issue(s) detectedPASS
CSS Performance Depth
1 CSS depth issue(s) detected
1 CSS depth issue(s) detected
Warning::
14 render-blocking stylesheet(s) -- recommended: <=3
Each `<link rel="stylesheet">` without a non-blocking `media` attribute holds up the first paint. Browsers download all of them before painting any content. Consolidate into 1-2 critical-path stylesheets; defer non-critical CSS via `<link rel="stylesheet" media="print" onload="this.media='all'">` or via the loadCSS pattern; inline above-the-fold CSS in `<style>` to short-circuit the request entirely.
A+HTTP Cachingmax-age=30 (30 seconds)PASS
HTTP Caching
max-age=30 (30 seconds)
max-age=30 (30 seconds)
Info::
Cache-Control header is set
Got: public, s-maxage=60, max-age=30, stale-while-revalidate=59
Info::
Effective TTL: 30 seconds (max-age=30)
Info::
CDN TTL: 1 minute (s-maxage=60)
Info::
ETag present — enables conditional (304) responses
Cache-Control
public, s-maxage=60, max-age=30, stale-while-revalidate=59
| Directive | Value | Meaning |
|---|---|---|
| public | — | Any cache may store this response |
| s-maxage | 60 | CDN caches for 1 minute |
| max-age | 30 | Cache for 30 seconds |
| stale-while-revalidate | 59 | Serve stale for 59 seconds while fetching fresh |
Effective TTL: 30 seconds
Network Waterfall524 requests over 1667msINFO
Network Waterfall
524 requests over 1667ms
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
38% of JavaScript execution is third-party
First-party Third-party 1095ms · 309KB · €12/mo
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
cuatro.sim-cdn.nl cuatro.sim-cdn.nl | Other | 555ms | 67 KB | 35% | €6/mo | Costly |
cuatro.sim-cdn.nl cuatro.sim-cdn.nl | Other | 191ms | 5 KB | — | €2/mo | Optional |
cuatro.sim-cdn.nl cuatro.sim-cdn.nl | Other | 165ms | 68 KB | 43% | €2/mo | Optional |
middelburg.logging.simanalytics.nl middelburg.logging.simanalytics.nl | Other | 76ms | 134 KB | 63% | €1/mo | Optional |
cuatro.sim-cdn.nl cuatro.sim-cdn.nl | Other | 55ms | 5 KB | — | €1/mo | Optional |
cuatro.sim-cdn.nl cuatro.sim-cdn.nl | Other | 53ms | 30 KB | — | €1/mo | Optional |
cuatro.sim-cdn.nl
Other
Execution 555ms
Transfer 67 KB
Unused 35%
Monthly Cost €6/mo
cuatro.sim-cdn.nl
Other
Execution 191ms
Transfer 5 KB
Monthly Cost €2/mo
cuatro.sim-cdn.nl
Other
Execution 165ms
Transfer 68 KB
Unused 43%
Monthly Cost €2/mo
middelburg.logging.simanalytics.nl
Other
Execution 76ms
Transfer 134 KB
Unused 63%
Monthly Cost €1/mo
cuatro.sim-cdn.nl
Other
Execution 55ms
Transfer 5 KB
Monthly Cost €1/mo
cuatro.sim-cdn.nl
Other
Execution 53ms
Transfer 30 KB
Monthly Cost €1/mo
These scripts may cost more than they're worth
- cuatro.sim-cdn.nl adds 555ms and costs ~€6/month
cuatro.sim-cdn.nl takes 555ms 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
63% of middelburg.logging.simanalytics.nl'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
Real-User Performance (CrUX)Field metrics from the Chrome User Experience ReportINFO
Real-User Performance (CrUX)
Field metrics from the Chrome User Experience Report
Chrome User Experience (CrUX)
Real-user metrics from the Chrome UX Report (2026-10-14 — 2026-11-10)
LCP (p75)
1158 ms
95% good
INP (p75)
154 ms
90% good
CLS (p75)
0.110
62% good
FCP (p75)
1024 ms
TTFB (p75)
438 ms
Image Optimization6 images, 0 KB total, 0 KB wastedINFO
Image Optimization
6 images, 0 KB total, 0 KB wasted
Image Optimization Audit
Total Images
6
Total Size
0 KB
Oversized
1
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.