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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
94
GRADE
A
FIX
2
REVIEW
1
PASS
12
INFO
2

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

Mobile Desktop
80
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
68
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
77
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
36
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.

2.95 s

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

2.95 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.

32.50 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.

2.95 s

Page Load Progression

2.8 s
5.6 s
8.4 s
11.2 s
14.0 s
16.8 s
19.6 s
22.4 s
Checks
17
12 PASS 1 REVIEW 2 FIX
D
Third-Party Impact
Action
98% third-party, 0 ms blocking
FIX
98% third-party, 0 ms blocking
Warning::
Third-party code accounts for 98% of page weight (19.8 KiB of 20.3 KiB)
Info::
Third-party blocking time is low (0 ms)
98%
First-party Third-party
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.

No Cache-Control header

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

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Page Weight Budget
20 KB transferred, 10 requests
PASS
20 KB transferred, 10 requests
Info::
Page weighs 24 KB (20 KB transferred)
Info::
10 HTTP requests
Info::
Estimated 0.00 g CO2 per page load
20 KB / 2.4 MB budget
20 KB transferred
10 requests
0.00 g CO2 per page load
Other 7.9 KiB 39%
HTML 7.4 KiB 36%
CSS 2.6 KiB 13%
Images 2.4 KiB 12%
0 2.4 MB 4.9 MB
Under budget
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
2 images, 0 KB saveable
PASS
2 images, 0 KB saveable
Info::
All images are well-optimized
2 images 2 KB
0 oversized -0 KB
2 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
207ms total JS execution
PASS
207ms total JS execution
Info::
Unattributable: 150ms CPU time
Info::
https://canalhistoria.es/: 57ms CPU time
Warning::
Third-party scripts: 207ms (100% of total)

Main Thread Breakdown

Other 60% Style & Layout 15% Garbage Collection 14% Script Evaluation 6%
ScriptTotalScriptingParse/CompileParty
Unattributable150ms4ms0ms3rd
https://canalhistoria.es/57ms6ms1ms3rd
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
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
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A
Page Weight Inventory
10 resources · 20 KB · 0 KB savings available
PASS
10 resources · 20 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 20 KB
Warning::
9 third-party resources (98% of weight)
10 resources · 20.3 KiB · 9 third-party Within 1MB page-weight target
Document 73% · 14.7 KiB
CSS 13% · 2.6 KiB
Image 12% · 2.4 KiB
Other 3% · 553 B
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
Network Waterfall
10 requests over 41712ms
INFO
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s 16.0 s 18.0 s 20.0 s 22.0 s 24.0 s 26.0 s 28.0 s 30.0 s 32.0 s 34.0 s 36.0 s 38.0 s 40.0 s 42.0 s FCP 3.0 s LCP 3.0 shttps://history.com// https://history.com/ — 301 — 490 B — 14 ms — h2https://www.history.com/www.history.com/ https://www.history.com/ — 302 — 63 B — 8 ms — h2http://canalhistoria.es/canalhistoria.es/ http://canalhistoria.es/ — 307 — 0 B — 2 ms — http/1.1https://canalhistoria.es/canalhistoria.es/ https://canalhistoria.es/ — 307 — 0 B — 3.0 s — http/1.1http://canalhistoria.es/canalhistoria.es/ http://canalhistoria.es/ — 307 — 0 B — 2 ms — http/1.1https://canalhistoria.es/canalhistoria.es/ https://canalhistoria.es/ — 522 — 7.4 KiB — 19.3 s — h3https://canalhistoria.es/cdn-cgi/styles/main.csscanalhistoria.es/cdn-cgi/styles/mai... https://canalhistoria.es/cdn-cgi/styles/main.css — 200 — 2.6 KiB — 21 ms — h3https://canalhistoria.es/cdn-cgi/images/cf-icon-ok.pngcanalhistoria.es/cdn-cgi/images/cf-... https://canalhistoria.es/cdn-cgi/images/cf-icon-ok.png — 200 — 1.3 KiB — 19 ms — h3https://canalhistoria.es/cdn-cgi/images/cf-icon-error.pngcanalhistoria.es/cdn-cgi/images/cf-... https://canalhistoria.es/cdn-cgi/images/cf-icon-error.png — 200 — 1.2 KiB — 20 ms — h3https://canalhistoria.es/favicon.icocanalhistoria.es/favicon.ico https://canalhistoria.es/favicon.ico — 522 — 7.3 KiB — 19.3 s — h3
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 207ms · 7KB · $3/mo
Unattributable
Other
Optional
Execution 150ms
Transfer 0 KB
Monthly Cost $2/mo
canalhistoria.es
Other
Optional
Execution 57ms
Transfer 7 KB
Monthly Cost $1/mo

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.

Learn more ▾

Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.

Source: web.dev

How third-party costs are calculated

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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