https://iol-website.italiaonline.it/site-resources... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://iol-website.italiaonline.it/site-resources... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://iol-website.italiaonline.it/site-resources... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://iol-website.italiaonline.it/site-resources... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
19images77 KB
0oversized-0 KB
9legacy format
4missing dimensionsCLS 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
B
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
i
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.
B
Compression Algorithm
Main response uses gzip; brotli would be ~20% smaller
REVIEW
Main response uses gzip; brotli would be ~20% smaller
Info::
i
Main HTML response uses gzip (brotli would be ~20% smaller)
All current browsers support brotli. Most CDNs (Cloudflare, Fastly, AWS CloudFront, Vercel, Netlify) can switch from gzip to brotli with a single config flag. Origin servers (nginx, Apache) need a brotli module compiled in -- nginx-brotli or Apache mod_brotli.
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
i
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.
B
JavaScript Blocking
2 JS blocking issue(s) detected
REVIEW
2 JS blocking issue(s) detected
Warning::
!
9 render-blocking <script src> tag(s) without async/defer
Each `<script src=...>` without `async`, `defer`, or `type="module"` blocks HTML parsing while the browser fetches and executes it. The block lasts the entire round-trip + execution time -- on slow networks this translates directly into LCP delay. Add `defer` (executes after parse, in source order) for scripts that interact with the DOM, or `async` (executes whenever ready) for analytics / independent scripts. Module scripts (`type="module"`) are deferred by default.
Warning::
!
Total JS execution time is 4.8 s -- over the 3.5s budget
Total JavaScript execution (parse + compile + run) across all scripts exceeds 3.5 seconds. On low-end devices that becomes 7-15+ seconds and shows up directly in TBT and INP. Reduce by: tree-shaking unused dependencies, code-splitting (dynamic `import()`), removing or deferring third-party tracking, and replacing heavy frameworks where they're not needed.
Each `<link rel="stylesheet">` without a non-blocking `media` attribute holds up the first paint. Browsers download all of them before painting any content. Consolidate into 1-2 critical-path stylesheets; defer non-critical CSS via `<link rel="stylesheet" media="print" onload="this.media='all'">` or via the loadCSS pattern; inline above-the-fold CSS in `<style>` to short-circuit the request entirely.
Warning::
!
4 `@font-face` rule(s) without `font-display` -- causes FOIT
An `@font-face` rule without `font-display` causes Flash of Invisible Text (FOIT): the browser hides the styled text for up to 3 seconds while the custom font downloads, then either swaps to fallback (Chrome / Firefox) or stays invisible (older Safari). Add `font-display: swap` (shows fallback immediately, swaps in the custom font when ready) or `font-display: optional` (uses fallback if the font isn't ready in 100ms; never causes visible swap). Either eliminates FOIT outright.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
5 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
5
316 KB total
Render-blocking
0
of 5
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size42 KB
Load time117 ms
Start134 ms
RiskFOUT — text flashes from fallback to web font
KFO5CnqEu92Fr1Mu53ZEC9_...woff2swap
Size46 KB
Load time130 ms
Start134 ms
RiskFOUT — text flashes from fallback to web font
fontawesome-webfont.woffwoffswap
Size96 KB
Load time63 ms
Start180 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
dm-common-icons.ttfttfswap
Size3 KB
Load time112 ms
Start786 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
bootstrap-icons.woff2woff2swap
Size128 KB
Load time190 ms
Start3.1 s
RiskFOUT — 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 ~94 KB and ~188 ms
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
4 hints, 0 missing preconnects
PASS
4 hints, 0 missing preconnects
Info::
i
1 URL(s) appear in multiple hints
The same href shouldn't appear in multiple hint rels -- one wins, the others are wasted markup and may confuse cache behavior. Sample: https://irp.cdn-website.com (preconnect+preconnect).
Info::
✓
Page uses 4 resource hint(s)
Current Resource Hints
preconnect
3
preload—
dns-prefetch—
prefetch
1
4 resource hints configured
The same href shouldn't appear in multiple hint rels -- one wins, the others are wasted markup and may confuse cache behavior. Sample: https://irp.cdn-website.com (preconnect+preconnect).
Why this matters
Performance issues directly impact user engagement and conversion rates.
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
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::
✓
`ETag` present -- conditional GET supported
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
114 requests over 5573ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
45%of JavaScript execution is third-party
First-party Third-party2179ms · 798KB · €12/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
consent.cookiebot.com
consent.cookiebot.com
Other
468ms
37 KB
—
€2/mo
Costly
iol-website.italiaonline.it
iol-website.italiaonline.it
Other
340ms
13 KB
—
€2/mo
Costly
static.cdn-website.com
static.cdn-website.com
Other
309ms
100 KB
60%
€2/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
250ms
161 KB
44%
€1/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
191ms
184 KB
40%
€1/mo
Optional
static.cdn-website.com
static.cdn-website.com
Other
190ms
4 KB
—
€1/mo
Optional
app.multiscreenstore.com
app.multiscreenstore.com
Other
130ms
0 KB
—
€1/mo
Optional
d1oxsl77a1kjht.cloudfront.net
d1oxsl77a1kjht.cloudfront.net
Other
95ms
118 KB
—
€1/mo
Optional
d34ikvsdm2rlij.cloudfront.net
d34ikvsdm2rlij.cloudfront.net
Other
84ms
17 KB
—
€0/mo
Optional
static.cdn-website.com
static.cdn-website.com
Other
69ms
3 KB
—
€0/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
52ms
161 KB
71%
€0/mo
Optional
consent.cookiebot.com
Other
Costly
Execution468ms
Transfer37 KB
Monthly Cost€2/mo
iol-website.italiaonline.it
Other
Costly
Execution340ms
Transfer13 KB
Monthly Cost€2/mo
static.cdn-website.com
Other
Costly
Execution309ms
Transfer100 KB
Unused60%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Costly
Execution250ms
Transfer161 KB
Unused44%
Monthly Cost€1/mo
Google Tag Manager
Tag Manager
Optional
Execution191ms
Transfer184 KB
Unused40%
Monthly Cost€1/mo
static.cdn-website.com
Other
Optional
Execution190ms
Transfer4 KB
Monthly Cost€1/mo
app.multiscreenstore.com
Other
Optional
Execution130ms
Transfer0 KB
Monthly Cost€1/mo
d1oxsl77a1kjht.cloudfront.net
Other
Optional
Execution95ms
Transfer118 KB
Monthly Cost€1/mo
d34ikvsdm2rlij.cloudfront.net
Other
Optional
Execution84ms
Transfer17 KB
Monthly Cost€0/mo
static.cdn-website.com
Other
Optional
Execution69ms
Transfer3 KB
Monthly Cost€0/mo
Google Tag Manager
Tag Manager
Optional
Execution52ms
Transfer161 KB
Unused71%
Monthly Cost€0/mo
These scripts may cost more than they're worth
consent.cookiebot.com adds 468ms and costs ~€2/month
iol-website.italiaonline.it adds 340ms and costs ~€2/month
static.cdn-website.com adds 309ms and costs ~€2/month
Google Tag Manager adds 250ms and costs ~€1/month
45% of JavaScript execution time comes from third-party scripts.
Why this matters
Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.
Learn more ▾▴
Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.
Source: web.dev / HTTP Archive Web Almanac
consent.cookiebot.com takes 468ms 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
iol-website.italiaonline.it takes 340ms 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
static.cdn-website.com takes 309ms 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
60% of static.cdn-website.com's code is unused. The script may be loading features you don't use.
Why this matters
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
Google Tag Manager takes 250ms 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
71% of Google Tag Manager's code is unused. The script may be loading features you don't use.
Why this matters
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.