https://timelinevisualizer.org
Performance
· 24 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.SCORE
90
GRADE
A
FIX
1
REVIEW
6
PASS
12
INFO
5
Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
95
100
100
100
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
1.06 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.22 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1 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.
1.06 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.
1.40 s
Page Load Progression
Checks
2412 PASS 6 REVIEW 1 FIX
FHTTP CachingActionNo cache headersFIX
HTTP Caching
ActionNo cache headers
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.
BImage Optimization37 images, 0 KB saveableREVIEW
Image Optimization
37 images, 0 KB saveable
37 images, 0 KB saveable
Info::
All images are well-optimized
37 images 332 KB
0 oversized -0 KB
37 legacy format
0 missing dimensions CLS risk
BJS Execution Cost941ms total JS executionREVIEW
JS Execution Cost
941ms total JS execution
941ms total JS execution
Warning::
https://timelinevisualizer.org/assets/routes-zB-0x...: 458ms CPU time
Info::
https://timelinevisualizer.org/assets/index-DJN9lH...: 180ms CPU time
Info::
https://timelinevisualizer.org/: 162ms CPU time
Info::
Unattributable: 72ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-FP7R...: 68ms CPU time
Info::
Third-party scripts: 68ms (7% of total)
Main Thread Breakdown
Other 56% Script Evaluation 27% Style & Layout 13%
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://timelinevisualizer.org/assets/routes-zB-0x1qy.js | 458ms | 56ms | 0ms | 1st |
| https://timelinevisualizer.org/assets/index-DJN9lHJw.js | 180ms | 135ms | 1ms | 1st |
| https://timelinevisualizer.org/ | 162ms | 4ms | 1ms | 1st |
| Unattributable | 72ms | 2ms | 0ms | 1st |
| https://www.googletagmanager.com/gtag/js?id=G-FP7R9K74SR | 68ms | 57ms | 10ms | 3rd |
CJS BundlesAction20 scripts, 154 KB unusedREVIEW
JS Bundles
Action20 scripts, 154 KB unused
20 scripts, 154 KB unused
Warning::
https://timelinevisualizer.org/assets/index-DJN9lH...: 80 KB unused (51%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-FP7R...: 74 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 154 KB
154 KB unused JavaScript
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://timelinevisualizer.org/assets/index-DJN9lHJw.js | 166 KB | 80 KB (51%) | ✓ | 1st |
| https://www.googletagmanager.com/gtag/js?id=G-FP7R9K74SR | 178 KB | 74 KB (42%) | ✓ | 3rd |
| https://timelinevisualizer.org/assets/upload-DEnnHPnK.js | 1 KB | — | ✓ | 1st |
| https://timelinevisualizer.org/assets/timeline_guide_title-DKxZDFdq.js | 2 KB | — | ✓ | 1st |
| https://timelinevisualizer.org/assets/react-dom-BGozS2fx.js | 2 KB | — | ✓ | 1st |
| https://timelinevisualizer.org/assets/routes-zB-0x1qy.js | 38 KB | — | ✓ | 1st |
| https://timelinevisualizer.org/assets/arrow-right-Cp1bLDz2.js | 1 KB | — | ✓ | 1st |
| https://timelinevisualizer.org/assets/folder-open-xoPWl98v.js | 1 KB | — | ✓ | 1st |
| https://timelinevisualizer.org/assets/header-DW0vfAoo.js | 5 KB | — | ✓ | 1st |
| https://timelinevisualizer.org/assets/timeline-route-canvas-DQ83HjL-.js | 10 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
BMain HTML Cache-ControlNo Cache-Control header on main HTML responseREVIEW
Main HTML Cache-Control
No Cache-Control header on main HTML response
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.
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
APage Weight Budget969 KB transferred, 68 requestsPASS
Page Weight Budget
969 KB transferred, 68 requests
969 KB transferred, 68 requests
Info::
Page weighs 2.0 MB (969 KB transferred)
Info::
68 HTTP requests
Info::
Estimated 0.20 g CO2 per page load
969 KB transferred
68 requests
0.20 g CO2 per page load
JavaScript 478.3 KiB 49%
Images 332.5 KiB 34%
Fonts 115.2 KiB 12%
CSS 26.7 KiB 3%
HTML 15.1 KiB 2%
Other 553 B 0%
Other 551 B 0%
Other 482 B 0%
0 2.4 MB 4.9 MB
Under budget
AThird-Party Impact38% third-party, 0 ms blockingPASS
Third-Party Impact
38% third-party, 0 ms blocking
38% third-party, 0 ms blocking
Info::
Third-party code accounts for 38% of page weight (367.5 KiB of 969.3 KiB)
Info::
Third-party blocking time is low (0 ms)
62%
38%
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 Loading6 fonts (115 KB)PASS
Font Loading
6 fonts (115 KB)
6 fonts (115 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
6
115 KB total
Render-blocking
0
of 6
Dominant font-display
swap
Most common across fonts
Font loading timeline
Transfer FOIT (block) FOUT (swap)
bricolage-grotesque-lat... woff2 swap
Size 41 KB
Load time 26 ms
Start 301 ms
Risk FOUT — text flashes from fallback to web font
karla-latin-wght-normal... woff2 swap
Size 32 KB
Load time 28 ms
Start 302 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-mono-vietnames... woff2 swap
Size 6 KB
Load time 27 ms
Start 302 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-mono-vietnames... woff2 swap
Size 6 KB
Load time 27 ms
Start 303 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-mono-latin-500... woff2 swap
Size 15 KB
Load time 71 ms
Start 371 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-mono-latin-400... woff2 swap
Size 15 KB
Load time 29 ms
Start 372 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 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+HTTP/3 (QUIC)HTTP/3 advertised via Alt-SvcPASS
HTTP/3 (QUIC)
HTTP/3 advertised via Alt-Svc
HTTP/3 advertised via Alt-Svc
Info::
HTTP/3 (QUIC) is supported
First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.
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.
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
AServer Response Intelligence2 server-response signal(s) detectedPASS
Server Response Intelligence
2 server-response signal(s) detected
2 server-response signal(s) detected
Warning::
Compressed response missing `Vary` header
The page is served with `Content-Encoding: br` 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.
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 Inventory68 resources · 969 KB · 154 KB savings availablePASS
Page Weight Inventory
68 resources · 969 KB · 154 KB savings available
68 resources · 969 KB · 154 KB savings available
Info::
Within 1MB page-weight target
Got: 969 KB
Info::
~154 KB of savings available
Info::
39 third-party resources (38% of weight)
68 resources · 969.3 KiB · 39 third-party Within 1MB page-weight target
JavaScript 49% · 478.3 KiB
Image 34% · 333.0 KiB
Font 12% · 115.2 KiB
CSS 3% · 26.7 KiB
Document 2% · 15.1 KiB
Other 0% · 1.1 KiB
~153.6 KiB of savings available
Remove unused JavaScript: 153.6 KiB
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 68 resources | 969.3 KiB | ||||||
Asset CompressionNo text asset hosts to measureINFO
Asset Compression
No text asset hosts to measure
No text asset hosts to measure
Info::
No third-party or subdomain host served enough text assets to measure
Asset compression is measured per host, from one HEAD request against a sampled resource. Pages that serve all their JS and CSS from the document's own origin are covered by the document compression check instead.
Network Waterfall68 requests over 690msINFO
Network Waterfall
68 requests over 690ms
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
7% of JavaScript execution is third-party
First-party Third-party 68ms · 178KB · €1/mo
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Google Tag Manager www.googletagmanager.com | Tag Manager | 68ms | 178 KB | 42% | €1/mo | Optional |
Google Tag Manager
Tag Manager
Execution 68ms
Transfer 178 KB
Unused 42%
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 (2026-10-01 — 2026-10-28)
LCP (p75)
2406 ms
77% good
INP (p75)
0 ms
0% good
CLS (p75)
0.000
100% good
FCP (p75)
2385 ms
TTFB (p75)
1558 ms
Image Optimization4 images, 144 KB total, 0 KB wastedINFO
Image Optimization
4 images, 144 KB total, 0 KB wasted
Image Optimization Audit
Total Images
4
Total Size
144 KB
2 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.