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https://www.colacem.com

Performance

· 23 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
87
GRADE
B
FIX
1
REVIEW
8
PASS
10
INFO
4

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

Mobile Desktop
83
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
77
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.
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.

503 ms

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

2.81 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.

0.002

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

1.41 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.

2.81 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
23
10 PASS 8 REVIEW 1 FIX
D
Page Weight Budget
Action
2.5 MB transferred, 25 requests
FIX
2.5 MB transferred, 25 requests
Warning::
Page weighs 3.0 MB (2.5 MB transferred)
Warning::
Images are 2.2 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 2.2 MB
Info::
25 HTTP requests
Info::
Estimated 0.53 g CO2 per page load
2.5 MB / 2.4 MB budget
2.5 MB transferred
25 requests
0.53 g CO2 per page load
Images 2.2 MiB 88%
JavaScript 160.3 KiB 6%
Fonts 75.4 KiB 3%
CSS 54.8 KiB 2%
HTML 6.4 KiB 0%
Other 4.7 KiB 0%
Other 164 B 0%
Other 146 B 0%
0 2.4 MB 4.9 MB
Over budget

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

C
Image Optimization
Action
12 images, 0 KB saveable
REVIEW
12 images, 0 KB saveable
Warning::
https://www.colacem.com/media/files/865_4_Logo_Col... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.colacem.com/img/search-w.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.colacem.com/media/immagini/1291_n_ENER... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.colacem.com/img/map.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.colacem.com/img/map-pin.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
12 images 2.2 MB
0 oversized -0 KB
12 legacy format
5 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

B
JS Bundles
4 scripts, 66 KB unused
REVIEW
4 scripts, 66 KB unused
Warning::
https://www.colacem.com/min/Layout_3_2405311332133...: 37 KB unused (65%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.matomo.cloud/colacem.matomo.cloud/cont...: 29 KB unused (52%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 66 KB
66 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.colacem.com/min/Layout_3_2405311332133213.js58 KB37 KB (65%)✓1st
https://cdn.matomo.cloud/colacem.matomo.cloud/container_aH7xjZRg.js56 KB29 KB (52%)✓3rd
https://www.colacem.com/js/vendor/jquery-2.1.1.min.js37 KB—✓1st
https://www.colacem.com/min/Layout_2_2306130937503750.js10 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

B
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
HTTP/3 (QUIC) is not advertised
HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.
C
Document Compression
Action
Document response served uncompressed
REVIEW
Document response served uncompressed
Info::
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
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
Page Weight Inventory
Action
25 resources · 2.5 MB · 66 KB savings available
REVIEW
25 resources · 2.5 MB · 66 KB savings available
Warning::
Page weight 2.5 MB exceeds 1 MB target by 1.5 MB
Got: 2.5 MB Expected: ≤ 1 MB
Info::
~66 KB of savings available
Info::
5 third-party resources (5% of weight)
Info::
1 resources over 200KB
25 resources · 2.5 MiB · 5 third-party 1.5 MiB over 1MB target
Image 89% · 2.2 MiB
JavaScript 6% · 160.3 KiB
Font 3% · 75.4 KiB
CSS 2% · 54.8 KiB
Document 0% · 6.4 KiB
Other 0% · 616 B

~66.2 KiB of savings available

Remove unused JavaScript: 66.2 KiB
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
no-cache
REVIEW
no-cache
Info::
Cache-Control header is set
Got: no-cache
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

no-cache

DirectiveValueMeaning
no-cache—Cache but always revalidate first
A+
Third-Party Impact
5% third-party, 0 ms blocking
PASS
5% third-party, 0 ms blocking
Info::
Third-party code accounts for 5% of page weight (131.3 KiB of 2.5 MiB)
Info::
Third-party blocking time is low (0 ms)
95%
First-party Third-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+
JS Execution Cost
152ms total JS execution
PASS
152ms total JS execution
Info::
https://www.colacem.com/es/es: 95ms CPU time
Info::
Unattributable: 57ms CPU time

Main Thread Breakdown

Script Evaluation 33% Other 32% Style & Layout 24% Script Parsing & Compilation 5% Rendering 4% Parse HTML & CSS 3%
ScriptTotalScriptingParse/CompileParty
https://www.colacem.com/es/es95ms5ms1ms1st
Unattributable57ms5ms0ms1st
A+
Font Loading
3 fonts (75 KB)
PASS
3 fonts (75 KB)
Info::
3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

3

75 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 500 ms 1.0 s 1.5 s 2.0 s 2.5 s FCP 503 ms LCP 2.8 shttps://fonts.gstatic.com/s/lato/v11/1YwB1sO8YE1Lyjf12WNiUA.woff21YwB1sO8YE1Lyjf12WNiUA.... https://fonts.gstatic.com/s/lato/v11/1YwB1sO8YE1Lyjf12WNiUA.woff2 — 25.6 KiB — 130 ms — font-display: swaphttps://fonts.gstatic.com/s/lato/v11/H2DMvhDLycM56KNuAtbJYA.woff2H2DMvhDLycM56KNuAtbJYA.... https://fonts.gstatic.com/s/lato/v11/H2DMvhDLycM56KNuAtbJYA.woff2 — 25.0 KiB — 127 ms — font-display: swaphttps://fonts.gstatic.com/s/lato/v11/EsvMC5un3kjyUhB9ZEPPwg.woff2EsvMC5un3kjyUhB9ZEPPwg.... https://fonts.gstatic.com/s/lato/v11/EsvMC5un3kjyUhB9ZEPPwg.woff2 — 24.8 KiB — 134 ms — font-display: swap
1YwB1sO8YE1Lyjf12WNiUA.... woff2 swap
Size 26 KB
Load time 130 ms
Start 489 ms
Risk FOUT — text flashes from fallback to web font
H2DMvhDLycM56KNuAtbJYA.... woff2 swap
Size 25 KB
Load time 127 ms
Start 490 ms
Risk FOUT — text flashes from fallback to web font
EsvMC5un3kjyUhB9ZEPPwg.... woff2 swap
Size 25 KB
Load time 134 ms
Start 490 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 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+
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+
Main HTML Cache-Control
Main HTML uses no-cache -- safe revalidate-on-request policy
PASS
Main HTML uses no-cache -- safe revalidate-on-request policy
Info::
Main HTML uses no-cache -- safe revalidate-on-request policy
Got: no-cache
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::
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.
Asset Compression
No text asset hosts to measure
INFO
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 Waterfall
25 requests over 948ms
INFO
0 ms 500 ms 1.0 s 1.5 s 2.0 s 2.5 s FCP 503 ms LCP 2.8 shttps://www.colacem.com// https://www.colacem.com/ — 301 — 306 B — 104 ms — h2https://www.colacem.com/es/es/es/es https://www.colacem.com/es/es — 200 — 6.4 KiB — 148 ms — h2https://www.colacem.com/min/Layout_0_2405311446344634.css/min/Layout_0_2405311446344634.css https://www.colacem.com/min/Layout_0_2405311446344634.css — 200 — 54.8 KiB — 137 ms — h2https://www.colacem.com/js/vendor/jquery-2.1.1.min.js/js/vendor/jquery-2.1.1.min.js https://www.colacem.com/js/vendor/jquery-2.1.1.min.js — 200 — 37.1 KiB — 88 ms — h2https://www.colacem.com/min/Layout_2_2306130937503750.js/min/Layout_2_2306130937503750.js https://www.colacem.com/min/Layout_2_2306130937503750.js — 200 — 10.0 KiB — 113 ms — h2https://www.colacem.com/img/close-lng.jpg/img/close-lng.jpg https://www.colacem.com/img/close-lng.jpg — 200 — 1.5 KiB — 112 ms — h2https://www.colacem.com/media/files/865_4_Logo_ColacemSpagna-bianco.png/media/files/865_4_Logo_ColacemSpag... https://www.colacem.com/media/files/865_4_Logo_ColacemSpagna-bianco.png — 200 — 9.3 KiB — 111 ms — h2https://www.colacem.com/img/search-w.png/img/search-w.png https://www.colacem.com/img/search-w.png — 200 — 1.3 KiB — 40 ms — h2https://www.colacem.com/media/immagini/1291_n_ENERGY%20sacco%20Cat%2042.5%20N%20210%20px.png/media/immagini/1291_n_ENERGY%20sac... https://www.colacem.com/media/immagini/1291_n_ENERGY%20sacco%20Cat%2042.5%20N%20210%20px.png — 200 — 71.3 KiB — 59 ms — h2https://www.colacem.com/img/map.png/img/map.png https://www.colacem.com/img/map.png — 200 — 31.7 KiB — 48 ms — h2https://www.colacem.com/min/Layout_3_2405311332133213.js/min/Layout_3_2405311332133213.js https://www.colacem.com/min/Layout_3_2405311332133213.js — 200 — 57.5 KiB — 66 ms — h2https://www.colacem.com/img/map-pin.png/img/map-pin.png https://www.colacem.com/img/map-pin.png — 200 — 1.5 KiB — 37 ms — h2https://cdn.matomo.cloud/colacem.matomo.cloud/container_aH7xjZRg.jscdn.matomo.cloud/colacem.matomo.clo... https://cdn.matomo.cloud/colacem.matomo.cloud/container_aH7xjZRg.js — 200 — 55.7 KiB — 59 ms — h2https://www.colacem.com/browserInfo.ashx?width=800&height=600&pxRatio=1/browserInfo.ashx?width=800&height=... https://www.colacem.com/browserInfo.ashx?width=800&height=600&pxRatio=1 — 200 — 164 B — 36 ms — h2https://www.colacem.com/img/ico-lang.png/img/ico-lang.png https://www.colacem.com/img/ico-lang.png — 200 — 3.0 KiB — 47 ms — h2https://www.colacem.com/media/immagini/542_n_colacem2.jpg/media/immagini/542_n_colacem2.jpg https://www.colacem.com/media/immagini/542_n_colacem2.jpg — 200 — 2.0 MiB — 464 ms — h2https://www.colacem.com/media/immagini/448_n_sostenibilita_home2.jpg/media/immagini/448_n_sostenibilita... https://www.colacem.com/media/immagini/448_n_sostenibilita_home2.jpg — 200 — 131.0 KiB — 74 ms — h2https://www.colacem.com/img/bg-h1.jpg/img/bg-h1.jpg https://www.colacem.com/img/bg-h1.jpg — 200 — 1.5 KiB — 46 ms — h2https://www.colacem.com/img/fb.png/img/fb.png https://www.colacem.com/img/fb.png — 200 — 1.3 KiB — 74 ms — h2https://fonts.gstatic.com/s/lato/v11/1YwB1sO8YE1Lyjf12WNiUA.woff2fonts.gstatic.com/s/lato/v11/1YwB1s... https://fonts.gstatic.com/s/lato/v11/1YwB1sO8YE1Lyjf12WNiUA.woff2 — 200 — 25.6 KiB — 130 ms — h3https://fonts.gstatic.com/s/lato/v11/H2DMvhDLycM56KNuAtbJYA.woff2fonts.gstatic.com/s/lato/v11/H2DMvh... https://fonts.gstatic.com/s/lato/v11/H2DMvhDLycM56KNuAtbJYA.woff2 — 200 — 25.0 KiB — 127 ms — h3https://fonts.gstatic.com/s/lato/v11/EsvMC5un3kjyUhB9ZEPPwg.woff2fonts.gstatic.com/s/lato/v11/EsvMC5... https://fonts.gstatic.com/s/lato/v11/EsvMC5un3kjyUhB9ZEPPwg.woff2 — 200 — 24.8 KiB — 134 ms — h3https://www.colacem.com/img/ajax-loader.gif/img/ajax-loader.gif https://www.colacem.com/img/ajax-loader.gif — 200 — 4.3 KiB — 57 ms — h2https://colacem.matomo.cloud/matomo.php?action_name=COLACEM%20-%20Producci%C3%B3n%20de%20cemento%20y%20ligantes%20hidr%C3%A1ulicos&idsite=1&rec=1&r=146432&h=14&m=40&s=5&url=https%3A%2F%2Fwww.colacem.com%2Fes%2Fes&_id=db338a3f8d3edb2d&_idn=1&send_image=0&_refts=0&pv_id=yTVLnY&fa_pv=1&fa_fp[0][fa_vid]=EjfOkE&fa_fp[0][fa_fv]=1&fa_fp[1][fa_vid]=oa9apK&fa_fp[1][fa_fv]=1&pf_net=0&pf_srv=147&pf_tfr=1&pf_dm1=275&uadata=%7B%22formFactors%22%3A%5B%22Desktop%22%5D%2C%22fullVersionList%22%3A%5B%7B%22brand%22%3A%22Not%20A(Brand%22%2C%22version%22%3A%2299.0.0.0%22%7D%2C%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22154.0.8037.92%22%7D%5D%2C%22mobile%22%3Afalse%2C%22model%22%3A%22%22%2C%22platform%22%3A%22macOS%22%2C%22platformVersion%22%3A%2210.15.7%22%7D&pdf=1&qt=0&realp=0&wma=0&fla=0&java=0&ag=0&cookie=1&res=800x600colacem.matomo.cloud/matomo.php?act... https://colacem.matomo.cloud/matomo.php?action_name=COLACEM%20-%20Producci%C3%B3n%20de%20cemento%20y%20ligantes%20hidr%C3%A1ulicos&idsite=1&rec=1&r=146432&h=14&m=40&s=5&url=https%3A%2F%2Fwww.colacem.com%2Fes%2Fes&_id=db338a3f8d3edb2d&_idn=1&send_image=0&_refts=0&pv_id=yTVLnY&fa_pv=1&fa_fp[0][fa_vid]=EjfOkE&fa_fp[0][fa_fv]=1&fa_fp[1][fa_vid]=oa9apK&fa_fp[1][fa_fv]=1&pf_net=0&pf_srv=147&pf_tfr=1&pf_dm1=275&uadata=%7B%22formFactors%22%3A%5B%22Desktop%22%5D%2C%22fullVersionList%22%3A%5B%7B%22brand%22%3A%22Not%20A(Brand%22%2C%22version%22%3A%2299.0.0.0%22%7D%2C%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22154.0.8037.92%22%7D%5D%2C%22mobile%22%3Afalse%2C%22model%22%3A%22%22%2C%22platform%22%3A%22macOS%22%2C%22platformVersion%22%3A%2210.15.7%22%7D&pdf=1&qt=0&realp=0&wma=0&fla=0&java=0&ag=0&cookie=1&res=800x600 — 204 — 146 B — 164 ms — h2https://www.colacem.com/favicon.ico?v=1.5/favicon.ico?v=1.5 https://www.colacem.com/favicon.ico?v=1.5 — 200 — 4.4 KiB — 40 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Real-User Performance (CrUX)
Field metrics from the Chrome User Experience Report
INFO

Chrome User Experience (CrUX)

Real-user metrics from the Chrome UX Report (2026-09-09 — 2026-10-06)

LCP (p75)

1488 ms

91% good

INP (p75)

85 ms

94% good

CLS (p75)

0.000

97% good

FCP (p75)

1007 ms

TTFB (p75)

593 ms

This origin passes Core Web Vitals assessment
Image Optimization
10 images, 121 KB total, 0 KB wasted
INFO

Image Optimization Audit

Total Images

10

Total Size

121 KB

8 missing alt text 10 missing dimensions 8 missing lazy loading
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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