https://fernandolaserna.com/prueba6/index.html
Performance
· 20 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.SCORE
92
GRADE
A
FIX
2
REVIEW
4
PASS
13
INFO
1
Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
94
90
96
100
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
1.20 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.20 s
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.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.20 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.
1.20 s
Page Load Progression
407 ms 815 ms
1.2 s
1.6 s
2.0 s
2.4 s 2.9 s
3.3 sChecks
2013 PASS 4 REVIEW 2 FIX
DThird-Party ImpactAction91% third-party, 0 ms blockingFIX
Third-Party Impact
Action91% third-party, 0 ms blocking
91% third-party, 0 ms blocking
Warning::
Third-party code accounts for 91% of page weight (243.3 KiB of 267.3 KiB)
Info::
Third-party blocking time is low (0 ms)
91%
First-party Third-party
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.
Info::
Last-Modified header present
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BJS Execution Cost628ms total JS executionREVIEW
JS Execution Cost
628ms total JS execution
628ms total JS execution
Warning::
https://fernandolaserna.com/prueba6/js/hero-canvas...: 410ms CPU time
Info::
https://fernandolaserna.com/prueba6/index.html: 218ms CPU time
Main Thread Breakdown
Other 47% Style & Layout 28% Script Evaluation 20%
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://fernandolaserna.com/prueba6/js/hero-canvas.js | 410ms | 135ms | 0ms | 1st |
| https://fernandolaserna.com/prueba6/index.html | 218ms | 1ms | 0ms | 1st |
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
A+Page Weight Budget267 KB transferred, 35 requestsPASS
Page Weight Budget
267 KB transferred, 35 requests
267 KB transferred, 35 requests
Info::
Page weighs 427 KB (267 KB transferred)
Info::
Fonts are 223 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 223 KB
Info::
35 HTTP requests
Info::
Estimated 0.05 g CO2 per page load
267 KB transferred
35 requests
0.05 g CO2 per page load
Fonts 222.7 KiB 83%
CSS 31.4 KiB 12%
HTML 7.3 KiB 3%
JavaScript 4.9 KiB 2%
Other 901 B 0%
0 2.4 MB 4.9 MB
Under budget
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
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+Image OptimizationNo images on this pagePASS
Image Optimization
No images on this page
No images on this page
Info::
No images on this page
0 images 0 KB
0 oversized -0 KB
0 legacy format
0 missing dimensions CLS risk
A+Font Loading3 fonts (223 KB)PASS
Font Loading
3 fonts (223 KB)
3 fonts (223 KB)
Info::
3 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
3
223 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
Transfer FOIT (block) FOUT (swap)
UcC73FwrK3iLTeHuS_nVMrM... woff2 swap
Size 47 KB
Load time 12 ms
Start 750 ms
Risk FOUT — text flashes from fallback to web font
V8mDoQDjQSkFtoMM3T6r8E7... woff2 swap
Size 22 KB
Load time 18 ms
Start 751 ms
Risk FOUT — text flashes from fallback to web font
fa-solid-900.woff2 woff2 swap
Size 154 KB
Load time 26 ms
Start 751 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 ~77 KB and ~154 ms
A+JS Bundles9 scripts, 0 KB unusedPASS
JS Bundles
9 scripts, 0 KB unused
9 scripts, 0 KB unused
0 KB unused JavaScript
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://fernandolaserna.com/prueba6/js/main.js | 0 KB | — | ✓ | 1st |
| https://fernandolaserna.com/prueba6/js/navbar.js | 0 KB | — | ✓ | 1st |
| https://fernandolaserna.com/prueba6/js/hero-canvas.js | 1 KB | — | ✓ | 1st |
| https://fernandolaserna.com/prueba6/js/reveal.js | 0 KB | — | ✓ | 1st |
| https://fernandolaserna.com/prueba6/js/faq.js | 0 KB | — | ✓ | 1st |
| https://fernandolaserna.com/prueba6/js/modal.js | 0 KB | — | ✓ | 1st |
| https://fernandolaserna.com/prueba6/js/form.js | 0 KB | — | ✓ | 1st |
| https://fernandolaserna.com/prueba6/js/smooth-scroll.js | 0 KB | — | ✓ | 1st |
| https://fernandolaserna.com/prueba6/js/cookie-consent.js | 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+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+Compression AlgorithmMain response uses brotliPASS
Compression Algorithm
Main response uses brotli
Main 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
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::
`Last-Modified` present -- timestamp-based conditional GET supported
Consider also setting `ETag` for stronger revalidation -- ETags are content hashes that don't suffer from clock-skew or DST issues. Last-Modified alone is functional for conditional GETs and not a bug.
APage Weight Inventory35 resources · 267 KB · 0 KB savings availablePASS
Page Weight Inventory
35 resources · 267 KB · 0 KB savings available
35 resources · 267 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 267 KB
Warning::
5 third-party resources (91% of weight)
35 resources · 267.3 KiB · 5 third-party Within 1MB page-weight target
Font 83% · 222.7 KiB
CSS 12% · 31.4 KiB
Document 3% · 8.2 KiB
JavaScript 2% · 4.9 KiB
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 35 resources | 267.3 KiB | ||||||
Network Waterfall35 requests over 966msINFO
Network Waterfall
35 requests over 966ms
HTML JavaScript CSS Images Fonts XHR/Fetch Other
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.