https://www.rhenen.nl
Performance
· 28 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.SCORE
92
GRADE
A
FIX
0
REVIEW
6
PASS
18
INFO
4
Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
77
100
92
100
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
2.17 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
4.79 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
82 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.
4.68 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.
4.81 s
Page Load Progression
Checks
2818 PASS 6 REVIEW
CImage OptimizationAction8 images, 0 KB saveableREVIEW
Image Optimization
Action8 images, 0 KB saveable
8 images, 0 KB saveable
Warning::
https://www.rhenen.nl/fileadmin/user_upload/Logo_R... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.rhenen.nl/fileadmin/_processed_/0/7/cs... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.rhenen.nl/fileadmin/_processed_/d/4/cs... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.rhenen.nl/fileadmin/_processed_/b/e/cs... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
8 images 126 KB
0 oversized -0 KB
5 legacy format
4 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
BJS Execution Cost837ms total JS executionREVIEW
JS Execution Cost
837ms total JS execution
837ms total JS execution
Warning::
https://www.rhenen.nl/: 449ms CPU time
Warning::
Unattributable: 250ms CPU time
Info::
https://static.rekai.se/da3053a5.js: 84ms CPU time
Info::
https://cdn-eu.readspeaker.com/script/6093/webRead...: 54ms CPU time
Info::
Third-party scripts: 138ms (16% of total)
Main Thread Breakdown
Other 39% Style & Layout 31% Script Evaluation 17% Parse HTML & CSS 5% Rendering 5%
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.rhenen.nl/ | 449ms | 5ms | 1ms | 1st |
| Unattributable | 250ms | 9ms | 0ms | 1st |
| https://static.rekai.se/da3053a5.js | 84ms | 67ms | 7ms | 3rd |
| https://cdn-eu.readspeaker.com/script/6093/webReader/webReader.js?pids=wr¬ools=1 | 54ms | 37ms | 8ms | 3rd |
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.
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.
BJavaScript Blocking1 JS blocking issue(s) detectedREVIEW
JavaScript Blocking
1 JS blocking issue(s) detected
1 JS blocking issue(s) detected
Warning::
5 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.
BHTTP Cachingno-cacheREVIEW
HTTP Caching
no-cache
no-cache
Info::
Cache-Control header is set
Got: no-cache
Info::
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+Page Weight Budget418 KB transferred, 88 requestsPASS
Page Weight Budget
418 KB transferred, 88 requests
418 KB transferred, 88 requests
Info::
Page weighs 937 KB (418 KB transferred)
Info::
88 HTTP requests
Info::
Estimated 0.09 g CO2 per page load
418 KB transferred
88 requests
0.09 g CO2 per page load
Images 125.8 KiB 30%
CSS 94.4 KiB 23%
Fonts 81.1 KiB 19%
JavaScript 75.6 KiB 18%
HTML 20.5 KiB 5%
Other 18.4 KiB 4%
Other 2.4 KiB 1%
Other 191 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Under budget
AThird-Party Impact33% third-party, 0 ms blockingPASS
Third-Party Impact
33% third-party, 0 ms blocking
33% third-party, 0 ms blocking
Info::
Third-party code accounts for 33% of page weight (139.4 KiB of 418.4 KiB)
Info::
Third-party blocking time is low (0 ms)
67%
33%
First-party Third-party
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 Loading5 fonts (81 KB)PASS
Font Loading
5 fonts (81 KB)
5 fonts (81 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
5
81 KB total
Render-blocking
0
of 5
Dominant font-display
swap
Most common across fonts
Font loading timeline
Transfer FOIT (block) FOUT (swap)
x-font-ttf;charset=utf-... unknown swap
Size 13 KB
Load time 54 ms
Start 656 ms
Risk FOUT — text flashes from fallback to web font
font-woff;charset=utf-8... woff swap
Size 25 KB
Load time 54 ms
Start 656 ms
Risk FOUT — text flashes from fallback to web font
- Convert to woff2 for ~30% smaller file size
open-sans-v15-latin-reg... woff2 swap
Size 14 KB
Load time 29 ms
Start 695 ms
Risk FOUT — text flashes from fallback to web font
open-sans-v15-latin-700... woff2 swap
Size 15 KB
Load time 30 ms
Start 695 ms
Risk FOUT — text flashes from fallback to web font
open-sans-v15-latin-600... woff2 swap
Size 15 KB
Load time 28 ms
Start 696 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)
Fixing the unchecked items could save ~11 KB and ~22 ms
A+JS Bundles17 scripts, 0 KB unusedPASS
JS Bundles
17 scripts, 0 KB unused
17 scripts, 0 KB unused
0 KB unused JavaScript
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.rhenen.nl/typo3temp/assets/js/573f81248d18dd4b567e70fe98a30b75.js?1794364281 | 1 KB | — | ✓ | 1st |
| https://cdn-eu.readspeaker.com/script/6093/webReader/webReader.js?pids=wr¬ools=1 | 28 KB | — | ✓ | 3rd |
| https://www.rhenen.nl/typo3temp/assets/js/0f851906d0fb8bbe408c0ec9ef59dfcc.js?1794364281 | 1 KB | — | ✓ | 1st |
| https://www.rhenen.nl/typo3temp/assets/js/d5d38c9b55b605775d83fc95c55d3360.js?1794364281 | 1 KB | — | ✓ | 1st |
| https://www.rhenen.nl/_assets/6c3bf359f8df9d9222347f37e2814501/JavaScript/OpenGemeentenSiteSearch-PageHeader-Search.min.js?1794359036 | 1 KB | — | ✓ | 1st |
| https://www.rhenen.nl/_assets/6c3bf359f8df9d9222347f37e2814501/JavaScript/OpenGemeentenSiteSearch-Suggest.min.js?1794359036 | 2 KB | — | ✓ | 1st |
| https://www.rhenen.nl/_assets/f52859db1e4f013bae2a279b52772e55/Js/OpenGemeentenCeFeatureCollapsible.min.js?1794359036 | 2 KB | — | ✓ | 1st |
| https://www.rhenen.nl/_assets/317130fbcbb12622b6e28e3bfff3cb16/Js/OpenGemeentenSite-Focusable.min.js?1794359036 | 1 KB | — | ✓ | 1st |
| https://www.rhenen.nl/_assets/317130fbcbb12622b6e28e3bfff3cb16/Js/OpenGemeentenSite-FragmentScroll.min.js?1794359036 | 1 KB | — | ✓ | 1st |
| https://www.rhenen.nl/_assets/317130fbcbb12622b6e28e3bfff3cb16/Js/OpenGemeentenSite-Media.min.js?1794359036 | 2 KB | — | ✓ | 1st |
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 HintsNo optimization neededPASS
Resource Hints
No optimization needed
No optimization needed
Info::
No resource hint issues
A+Document CompressionDocument response uses brotliPASS
Document Compression
Document response uses brotli
Document response uses brotli
Info::
Main HTML response uses brotli (Content-Encoding: br)
Brotli is the best text-compression algorithm for general use, ~20% smaller than gzip on average (40% on smaller files). Modern browsers all support it.
AAsset Compression1 of 1 asset host still on gzipPASS
Asset Compression
1 of 1 asset host still on gzip
1 of 1 asset host still on gzip
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)
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 uses no-cache -- safe revalidate-on-request policyPASS
Main HTML Cache-Control
Main HTML uses no-cache -- safe revalidate-on-request policy
Main HTML uses no-cache -- safe revalidate-on-request policy
Info::
Main HTML uses no-cache -- safe revalidate-on-request policy
Got: no-cache
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::
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 Inventory88 resources · 418 KB · 0 KB savings availablePASS
Page Weight Inventory
88 resources · 418 KB · 0 KB savings available
88 resources · 418 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 418 KB
Info::
14 third-party resources (33% of weight)
88 resources · 418.4 KiB · 14 third-party Within 1MB page-weight target
Image 34% · 144.3 KiB
CSS 23% · 94.4 KiB
Font 19% · 81.1 KiB
JavaScript 18% · 75.6 KiB
Document 5% · 22.8 KiB
Other 0% · 275 B
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 88 resources | 418.4 KiB | ||||||
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
ACSS Performance Depth1 CSS depth issue(s) detectedPASS
CSS Performance Depth
1 CSS depth issue(s) detected
1 CSS depth issue(s) detected
Warning::
46 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+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
Whether the site is served from green-energy infrastructure
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall88 requests over 1148msINFO
Network Waterfall
88 requests over 1148ms
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
16% of JavaScript execution is third-party
First-party Third-party 138ms · 54KB · €2/mo
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
static.rekai.se static.rekai.se | Other | 84ms | 26 KB | — | €1/mo | Optional |
cdn-eu.readspeaker.com cdn-eu.readspeaker.com | Other | 54ms | 28 KB | — | €1/mo | Optional |
static.rekai.se
Other
Execution 84ms
Transfer 26 KB
Monthly Cost €1/mo
cdn-eu.readspeaker.com
Other
Execution 54ms
Transfer 28 KB
Monthly Cost €1/mo
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)
1082 ms
95% good
INP (p75)
70 ms
99% good
CLS (p75)
0.000
98% good
FCP (p75)
1006 ms
TTFB (p75)
486 ms
This origin passes Core Web Vitals assessment
Image Optimization5 images, 403 KB total, 0 KB wastedINFO
Image Optimization
5 images, 403 KB total, 0 KB wasted
Image Optimization Audit
Total Images
5
Total Size
403 KB
5 missing dimensions 3 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.