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Performance

· 24 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
92
GRADE
A
FIX
3
REVIEW
3
PASS
17
INFO
1

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

Mobile Desktop
82
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
92
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
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.

3.61 s

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

3.61 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.

3.70 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.

3.61 s

Page Load Progression

456 ms
911 ms
1.4 s
1.8 s
2.3 s
2.7 s
3.2 s
3.6 s
Checks
24
17 PASS 3 REVIEW 3 FIX
D
Third-Party Impact
Action
94% third-party, 0 ms blocking
FIX
94% third-party, 0 ms blocking
Warning::
Third-party code accounts for 94% of page weight (243.2 KiB of 257.8 KiB)
Info::
Third-party blocking time is low (0 ms)
94%
First-party Third-party
D
JS Execution Cost
Action
2256ms total JS execution
FIX
2256ms total JS execution
Warning::
https://fernandolaserna.com/prueba5/: 2103ms CPU time
Info::
Unattributable: 153ms CPU time

Main Thread Breakdown

Other 47% Script Evaluation 26% Style & Layout 21% Rendering 4%
ScriptTotalScriptingParse/CompileParty
https://fernandolaserna.com/prueba5/2103ms604ms3ms1st
Unattributable153ms7ms0ms1st
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.
Info::
Last-Modified header present

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

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
258 KB transferred, 7 requests
PASS
258 KB transferred, 7 requests
Info::
Page weighs 419 KB (258 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::
7 HTTP requests
Info::
Estimated 0.05 g CO2 per page load
258 KB / 2.4 MB budget
258 KB transferred
7 requests
0.05 g CO2 per page load
Fonts 222.7 KiB 86%
CSS 20.5 KiB 8%
HTML 13.7 KiB 5%
Other 878 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 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+
Image Optimization
No images on this page
PASS
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 Loading
3 fonts (223 KB)
PASS
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)
0 ms 1.0 s 2.0 s 3.0 s FCP 3.6 s LCP 3.6 shttps://fonts.gstatic.com/s/inter/v20/UcC73FwrK3iLTeHuS_nVMrMxCp50SjIa1ZL7W0Q5nw.woff2UcC73FwrK3iLTeHuS_nVMrM... https://fonts.gstatic.com/s/inter/v20/UcC73FwrK3iLTeHuS_nVMrMxCp50SjIa1ZL7W0Q5nw.woff2 — 47.3 KiB — 85 ms — font-display: swaphttps://fonts.gstatic.com/s/spacegrotesk/v22/V8mDoQDjQSkFtoMM3T6r8E7mPbF4C_k3HqU.woff2V8mDoQDjQSkFtoMM3T6r8E7... https://fonts.gstatic.com/s/spacegrotesk/v22/V8mDoQDjQSkFtoMM3T6r8E7mPbF4C_k3HqU.woff2 — 21.8 KiB — 77 ms — font-display: swaphttps://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/webfonts/fa-solid-900.woff2fa-solid-900.woff2 https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/webfonts/fa-solid-900.woff2 — 153.5 KiB — 78 ms — font-display: swap
UcC73FwrK3iLTeHuS_nVMrM... woff2 swap
Size 47 KB
Load time 85 ms
Start 289 ms
Risk FOUT — text flashes from fallback to web font
V8mDoQDjQSkFtoMM3T6r8E7... woff2 swap
Size 22 KB
Load time 77 ms
Start 290 ms
Risk FOUT — text flashes from fallback to web font
fa-solid-900.woff2 woff2 swap
Size 154 KB
Load time 78 ms
Start 290 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 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
2 hints, 0 missing preconnects
PASS
2 hints, 0 missing preconnects
Info::
Page uses 2 resource hint(s)

Current Resource Hints

preconnect
2
preload
—
dns-prefetch
—
prefetch
—

2 resource hints configured

A+
HTTP/3 (QUIC)
HTTP/3 advertised via Alt-Svc
PASS
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 Algorithm
Main response uses brotli
PASS
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 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
2 server-response signal(s) detected
PASS
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.
A
Page Weight Inventory
7 resources · 258 KB · 0 KB savings available
PASS
7 resources · 258 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 258 KB
Warning::
5 third-party resources (94% of weight)
7 resources · 257.8 KiB · 5 third-party Within 1MB page-weight target
Font 86% · 222.7 KiB
CSS 8% · 20.5 KiB
Document 6% · 14.6 KiB
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
A+
JavaScript Blocking
No render-blocking JS or document.write usage detected
PASS
No render-blocking JS or document.write usage detected
Info::
No JavaScript blocking issues detected
A+
CSS Performance Depth
No CSS performance depth issues detected
PASS
No CSS performance depth issues detected
Info::
No CSS performance depth issues detected
Network Waterfall
7 requests over 411ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 3.6 s LCP 3.6 shttps://fernandolaserna.com/prueba5//prueba5/ https://fernandolaserna.com/prueba5/ — 200 — 13.7 KiB — 16 ms — h2https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Space+Grotesk:wght@400;500;600;700&display=swapfonts.googleapis.com/css2?family=In... https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Space+Grotesk:wght@400;500;600;700&display=swap — 200 — 1.5 KiB — 168 ms — h2https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.csscdnjs.cloudflare.com/ajax/libs/font... https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css — 200 — 19.1 KiB — 105 ms — h3https://fonts.gstatic.com/s/inter/v20/UcC73FwrK3iLTeHuS_nVMrMxCp50SjIa1ZL7W0Q5nw.woff2fonts.gstatic.com/s/inter/v20/UcC73... https://fonts.gstatic.com/s/inter/v20/UcC73FwrK3iLTeHuS_nVMrMxCp50SjIa1ZL7W0Q5nw.woff2 — 200 — 47.3 KiB — 85 ms — h3https://fonts.gstatic.com/s/spacegrotesk/v22/V8mDoQDjQSkFtoMM3T6r8E7mPbF4C_k3HqU.woff2fonts.gstatic.com/s/spacegrotesk/v2... https://fonts.gstatic.com/s/spacegrotesk/v22/V8mDoQDjQSkFtoMM3T6r8E7mPbF4C_k3HqU.woff2 — 200 — 21.8 KiB — 77 ms — h3https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/webfonts/fa-solid-900.woff2cdnjs.cloudflare.com/ajax/libs/font... https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/webfonts/fa-solid-900.woff2 — 200 — 153.5 KiB — 78 ms — h3https://fernandolaserna.com/favicon.ico/favicon.ico https://fernandolaserna.com/favicon.ico — 404 — 878 B — 4 ms — h2
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.

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