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https://boe.es

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
94
GRADE
A
FIX
1
REVIEW
3
PASS
11
INFO
2

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

Mobile Desktop
93
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.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
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.

1.35 s

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

3.15 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.

0.003

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

1.35 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.

3.15 s

Page Load Progression

397 ms
794 ms
1.2 s
1.6 s
2.0 s
2.4 s
2.8 s
3.2 s
Checks
17
11 PASS 3 REVIEW 1 FIX
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
Image Optimization
Action
25 images, 0 KB saveable
REVIEW
25 images, 0 KB saveable
Warning::
https://boe.es/imagenes/home/teu_270.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/anunciantes.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/rss_32.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/logoBlanco128.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/logoBuscar.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/subastas_270.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/twitter_32.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/facebook_32.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/teju_270.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/datos_abiertos_mono.s... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/youtube_32.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/logoMiBOE.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://boe.es/imagenes/home/linkedin_32.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
25 images 699 KB
0 oversized -0 KB
25 legacy format
13 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

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

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

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

B
JS Execution Cost
585ms total JS execution
REVIEW
585ms total JS execution
Warning::
Unattributable: 413ms CPU time
Info::
https://boe.es/: 172ms CPU time
Warning::
Third-party scripts: 413ms (71% of total)

Main Thread Breakdown

Other 63% Style & Layout 22% Rendering 9% Script Evaluation 3%
ScriptTotalScriptingParse/CompileParty
Unattributable413ms7ms0ms3rd
https://boe.es/172ms3ms1ms1st
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Page Weight Budget
779 KB transferred, 31 requests
PASS
779 KB transferred, 31 requests
Info::
Page weighs 757 KB (779 KB transferred)
Info::
31 HTTP requests
Info::
Estimated 0.16 g CO2 per page load
779 KB / 2.4 MB budget
779 KB transferred
31 requests
0.16 g CO2 per page load
Images 698.8 KiB 90%
CSS 48.9 KiB 6%
HTML 23.3 KiB 3%
JavaScript 5.4 KiB 1%
Other 2.1 KiB 0%
0 2.4 MB 4.9 MB
Under budget
A+
Third-Party Impact
No third-party resources
PASS
No third-party resources
Info::
No third-party resources detected
No third-party resources detected — all resources are first-party.
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+
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
1 scripts, 0 KB unused
PASS
1 scripts, 0 KB unused
Warning::
https://boe.es/js/desplegable.js: unminified — 2 KB could be saved
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://boe.es/js/desplegable.js5 KB—✗1st
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
31 resources · 779 KB · 0 KB savings available
PASS
31 resources · 779 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 779 KB
31 resources · 778.6 KiB · 0 third-party Within 1MB page-weight target
Image 90% · 701.0 KiB
CSS 6% · 48.9 KiB
Document 3% · 23.3 KiB
JavaScript 1% · 5.4 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
Network Waterfall
31 requests over 3181ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 1.4 s LCP 3.2 shttps://boe.es// https://boe.es/ — 200 — 23.3 KiB — 15 ms — http/1.1https://boe.es/estilos/boe.css/estilos/boe.css https://boe.es/estilos/boe.css — 200 — 38.4 KiB — 13 ms — http/1.1https://boe.es/estilos/home.css/estilos/home.css https://boe.es/estilos/home.css — 200 — 10.6 KiB — 18 ms — http/1.1https://boe.es/imagenes/logoMPRmovil.svg/imagenes/logoMPRmovil.svg https://boe.es/imagenes/logoMPRmovil.svg — 200 — 137.5 KiB — 21 ms — http/1.1https://boe.es/imagenes/logoMPR.svg/imagenes/logoMPR.svg https://boe.es/imagenes/logoMPR.svg — 200 — 177.8 KiB — 1.0 s — http/1.1https://boe.es/imagenes/logoBOE.svg/imagenes/logoBOE.svg https://boe.es/imagenes/logoBOE.svg — 200 — 17.5 KiB — 1.1 s — http/1.1https://boe.es/imagenes/logoBlanco128.png/imagenes/logoBlanco128.png https://boe.es/imagenes/logoBlanco128.png — 200 — 20.0 KiB — 3.1 s — http/1.1https://boe.es/js/desplegable.js/js/desplegable.js https://boe.es/js/desplegable.js — 200 — 5.4 KiB — 10 ms — http/1.1https://boe.es/imagenes/logoBuscar.svg/imagenes/logoBuscar.svg https://boe.es/imagenes/logoBuscar.svg — 200 — 1.9 KiB — 207 ms — http/1.1https://boe.es/imagenes/logoMiBOE.svg/imagenes/logoMiBOE.svg https://boe.es/imagenes/logoMiBOE.svg — 200 — 1.5 KiB — 1.3 s — http/1.1https://boe.es/imagenes/home/boe-01.jpg/imagenes/home/boe-01.jpg https://boe.es/imagenes/home/boe-01.jpg — 200 — 51.8 KiB — 1.3 s — http/1.1https://boe.es/imagenes/home/europa.jpg/imagenes/home/europa.jpg https://boe.es/imagenes/home/europa.jpg — 200 — 57.6 KiB — 176 ms — http/1.1https://boe.es/imagenes/home/brm-01.jpg/imagenes/home/brm-01.jpg https://boe.es/imagenes/home/brm-01.jpg — 200 — 36.4 KiB — 180 ms — http/1.1https://boe.es/imagenes/ico_bullet.svg/imagenes/ico_bullet.svg https://boe.es/imagenes/ico_bullet.svg — 200 — 1.5 KiB — 184 ms — http/1.1https://boe.es/imagenes/home/bl-01.jpg/imagenes/home/bl-01.jpg https://boe.es/imagenes/home/bl-01.jpg — 200 — 48.6 KiB — 1.1 s — http/1.1https://boe.es/imagenes/home/bl-01_full.jpg/imagenes/home/bl-01_full.jpg https://boe.es/imagenes/home/bl-01_full.jpg — 200 — 52.9 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/bj-01.jpg/imagenes/home/bj-01.jpg https://boe.es/imagenes/home/bj-01.jpg — 200 — 28.8 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/bj-01_full.jpg/imagenes/home/bj-01_full.jpg https://boe.es/imagenes/home/bj-01_full.jpg — 200 — 30.0 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/teu_270.svg/imagenes/home/teu_270.svg https://boe.es/imagenes/home/teu_270.svg — 200 — 3.9 KiB — 6 ms — http/1.1https://boe.es/imagenes/home/teju_270.svg/imagenes/home/teju_270.svg https://boe.es/imagenes/home/teju_270.svg — 200 — 6.8 KiB — 1.1 s — http/1.1https://boe.es/imagenes/home/subastas_270.svg/imagenes/home/subastas_270.svg https://boe.es/imagenes/home/subastas_270.svg — 200 — 2.7 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/anunciantes.svg/imagenes/home/anunciantes.svg https://boe.es/imagenes/home/anunciantes.svg — 200 — 2.0 KiB — 3 ms — http/1.1https://boe.es/imagenes/home/datos_abiertos_mono.svg/imagenes/home/datos_abiertos_mono.... https://boe.es/imagenes/home/datos_abiertos_mono.svg — 200 — 9.3 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/rss_32.svg/imagenes/home/rss_32.svg https://boe.es/imagenes/home/rss_32.svg — 200 — 1.9 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/twitter_32.svg/imagenes/home/twitter_32.svg https://boe.es/imagenes/home/twitter_32.svg — 200 — 1.6 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/facebook_32.svg/imagenes/home/facebook_32.svg https://boe.es/imagenes/home/facebook_32.svg — 200 — 1.5 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/linkedin_32.svg/imagenes/home/linkedin_32.svg https://boe.es/imagenes/home/linkedin_32.svg — 200 — 1.8 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/youtube_32.svg/imagenes/home/youtube_32.svg https://boe.es/imagenes/home/youtube_32.svg — 200 — 2.2 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/lupa_24x24.png/imagenes/home/lupa_24x24.png https://boe.es/imagenes/home/lupa_24x24.png — 200 — 1.4 KiB — 4 ms — http/1.1https://boe.es/favicon.ico/favicon.ico https://boe.es/favicon.ico — 200 — 2.1 KiB — 4 ms — http/1.1
0 ms 1.0 s 2.0 s 3.0 s FCP 1.4 s LCP 3.2 shttps://boe.es// https://boe.es/ — 200 — 23.3 KiB — 15 ms — http/1.1https://boe.es/estilos/boe.css/estilos/boe.css https://boe.es/estilos/boe.css — 200 — 38.4 KiB — 13 ms — http/1.1https://boe.es/estilos/home.css/estilos/home.css https://boe.es/estilos/home.css — 200 — 10.6 KiB — 18 ms — http/1.1https://boe.es/imagenes/logoMPRmovil.svg/imagenes/logoMPRmovil.svg https://boe.es/imagenes/logoMPRmovil.svg — 200 — 137.5 KiB — 21 ms — http/1.1https://boe.es/imagenes/logoMPR.svg/imagenes/logoMPR.svg https://boe.es/imagenes/logoMPR.svg — 200 — 177.8 KiB — 1.0 s — http/1.1https://boe.es/imagenes/logoBOE.svg/imagenes/logoBOE.svg https://boe.es/imagenes/logoBOE.svg — 200 — 17.5 KiB — 1.1 s — http/1.1https://boe.es/imagenes/logoBlanco128.png/imagenes/logoBlanco128.png https://boe.es/imagenes/logoBlanco128.png — 200 — 20.0 KiB — 3.1 s — http/1.1https://boe.es/js/desplegable.js/js/desplegable.js https://boe.es/js/desplegable.js — 200 — 5.4 KiB — 10 ms — http/1.1https://boe.es/imagenes/logoBuscar.svg/imagenes/logoBuscar.svg https://boe.es/imagenes/logoBuscar.svg — 200 — 1.9 KiB — 207 ms — http/1.1https://boe.es/imagenes/logoMiBOE.svg/imagenes/logoMiBOE.svg https://boe.es/imagenes/logoMiBOE.svg — 200 — 1.5 KiB — 1.3 s — http/1.1https://boe.es/imagenes/home/boe-01.jpg/imagenes/home/boe-01.jpg https://boe.es/imagenes/home/boe-01.jpg — 200 — 51.8 KiB — 1.3 s — http/1.1https://boe.es/imagenes/home/europa.jpg/imagenes/home/europa.jpg https://boe.es/imagenes/home/europa.jpg — 200 — 57.6 KiB — 176 ms — http/1.1https://boe.es/imagenes/home/brm-01.jpg/imagenes/home/brm-01.jpg https://boe.es/imagenes/home/brm-01.jpg — 200 — 36.4 KiB — 180 ms — http/1.1https://boe.es/imagenes/ico_bullet.svg/imagenes/ico_bullet.svg https://boe.es/imagenes/ico_bullet.svg — 200 — 1.5 KiB — 184 ms — http/1.1https://boe.es/imagenes/home/bl-01.jpg/imagenes/home/bl-01.jpg https://boe.es/imagenes/home/bl-01.jpg — 200 — 48.6 KiB — 1.1 s — http/1.1https://boe.es/imagenes/home/bl-01_full.jpg/imagenes/home/bl-01_full.jpg https://boe.es/imagenes/home/bl-01_full.jpg — 200 — 52.9 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/bj-01.jpg/imagenes/home/bj-01.jpg https://boe.es/imagenes/home/bj-01.jpg — 200 — 28.8 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/bj-01_full.jpg/imagenes/home/bj-01_full.jpg https://boe.es/imagenes/home/bj-01_full.jpg — 200 — 30.0 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/teu_270.svg/imagenes/home/teu_270.svg https://boe.es/imagenes/home/teu_270.svg — 200 — 3.9 KiB — 6 ms — http/1.1https://boe.es/imagenes/home/teju_270.svg/imagenes/home/teju_270.svg https://boe.es/imagenes/home/teju_270.svg — 200 — 6.8 KiB — 1.1 s — http/1.1https://boe.es/imagenes/home/subastas_270.svg/imagenes/home/subastas_270.svg https://boe.es/imagenes/home/subastas_270.svg — 200 — 2.7 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/anunciantes.svg/imagenes/home/anunciantes.svg https://boe.es/imagenes/home/anunciantes.svg — 200 — 2.0 KiB — 3 ms — http/1.1https://boe.es/imagenes/home/datos_abiertos_mono.svg/imagenes/home/datos_abiertos_mono.... https://boe.es/imagenes/home/datos_abiertos_mono.svg — 200 — 9.3 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/rss_32.svg/imagenes/home/rss_32.svg https://boe.es/imagenes/home/rss_32.svg — 200 — 1.9 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/twitter_32.svg/imagenes/home/twitter_32.svg https://boe.es/imagenes/home/twitter_32.svg — 200 — 1.6 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/facebook_32.svg/imagenes/home/facebook_32.svg https://boe.es/imagenes/home/facebook_32.svg — 200 — 1.5 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/linkedin_32.svg/imagenes/home/linkedin_32.svg https://boe.es/imagenes/home/linkedin_32.svg — 200 — 1.8 KiB — 4 ms — http/1.1https://boe.es/imagenes/home/youtube_32.svg/imagenes/home/youtube_32.svg https://boe.es/imagenes/home/youtube_32.svg — 200 — 2.2 KiB — 1.0 s — http/1.1https://boe.es/imagenes/home/lupa_24x24.png/imagenes/home/lupa_24x24.png https://boe.es/imagenes/home/lupa_24x24.png — 200 — 1.4 KiB — 4 ms — http/1.1https://boe.es/favicon.ico/favicon.ico https://boe.es/favicon.ico — 200 — 2.1 KiB — 4 ms — http/1.1https://boe.es/favicon.ico/favicon.ico https://boe.es/favicon.ico — 200 — 0 B — 1 ms — http/1.1
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
71% of JavaScript execution is third-party
First-party Third-party 413ms · 0KB · €4/mo
Unattributable
Other
Costly
Execution 413ms
Transfer 0 KB
Monthly Cost €4/mo

These scripts may cost more than they're worth

  • Unattributable adds 413ms and costs ~€4/month

71% 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

Unattributable takes 413ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

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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