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.
B
Image Optimization
12 images, 0 KB saveable
REVIEW
12 images, 0 KB saveable
Warning::
!
https://www.fiat.com/content/dam/fiat2023/master/L... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
12images526 KB
0oversized-0 KB
9legacy format
1missing 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
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.
C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
i
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
Main HTML Cache-Control
No Cache-Control header on main HTML response
REVIEW
No Cache-Control header on main HTML response
Info::
i
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::
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::
!
2 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 4.7 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.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW
Green Hosting
No green hosting detected
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
13 fonts (358 KB)
PASS
13 fonts (358 KB)
Info::
i
13 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
13
358 KB total
Render-blocking
0
of 13
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
pxiByp8kv8JHgFVrLCz7Z1x...woff2swap
Size8 KB
Load time122 ms
Start361 ms
RiskFOUT — text flashes from fallback to web font
pxiEyp8kv8JHgFVrJJfecnF...woff2swap
Size8 KB
Load time122 ms
Start362 ms
RiskFOUT — text flashes from fallback to web font
PSAGroupeHMISans-Regula...woffswap
Size117 KB
Load time40 ms
Start362 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
icomoon.woffwoffswap
Size47 KB
Load time52 ms
Start362 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
fiat-2023.ttfttfswap
Size80 KB
Load time48 ms
Start707 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size34 KB
Load time153 ms
Start848 ms
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size0 KB
Load time118 ms
Start906 ms
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size0 KB
Load time110 ms
Start942 ms
RiskFOUT — text flashes from fallback to web font
Poppins-Bold.ttfttfswap
Size65 KB
Load time101 ms
Start961 ms
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size0 KB
Load time83 ms
Start991 ms
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size0 KB
Load time101 ms
Start994 ms
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size0 KB
Load time106 ms
Start997 ms
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size0 KB
Load time84 ms
Start1.0 s
RiskFOUT — 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)
Fixing the unchecked items could save ~151 KB and ~302 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
1 hints, 0 missing preconnects
PASS
1 hints, 0 missing preconnects
Warning::
!
1 preload hint(s) missing `as` attribute
Browsers ignore or refetch preloads without an `as` attribute -- the preload effort is wasted. Sample: https://cookielaw.emea.fcagroup.com/CookieLawProduct/resources/generatecss?key=3417. Add the right `as` value (e.g., `as="font"`, `as="image"`, `as="script"`) on each.
Info::
✓
Page uses 1 resource hint(s)
Current Resource Hints
preconnect—
preload
1
dns-prefetch—
prefetch—
1 resource hints configured
Browsers ignore or refetch preloads without an `as` attribute -- the preload effort is wasted. Sample: https://cookielaw.emea.fcagroup.com/CookieLawProduct/resources/generatecss?key=3417. Add the right `as` value (e.g., `as="font"`, `as="image"`, `as="script"`) on each.
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+
Server Response Intelligence
1 server-response signal(s) detected
PASS
1 server-response signal(s) detected
Info::
i
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.
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.
Network Waterfall
145 requests over 6228ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
92%of JavaScript execution is third-party
First-party Third-party4321ms · 782KB · €47/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.fiat.com
www.fiat.com
Other
995ms
50 KB
47%
€11/mo
Costly
www.fiat.com
www.fiat.com
Other
754ms
20 KB
—
€8/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
419ms
130 KB
50%
€5/mo
Costly
www.fiat.com
www.fiat.com
Other
341ms
4 KB
—
€4/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
289ms
136 KB
45%
€3/mo
Costly
www.fiat.com
www.fiat.com
Other
265ms
41 KB
—
€3/mo
Costly
assets.adobedtm.com
assets.adobedtm.com
Other
180ms
70 KB
31%
€2/mo
Optional
www.fiat.com
www.fiat.com
Other
179ms
95 KB
46%
€2/mo
Optional
www.fiat.com
www.fiat.com
Other
170ms
3 KB
—
€2/mo
Optional
www.fiat.com
www.fiat.com
Other
162ms
54 KB
—
€2/mo
Optional
www.fiat.com
www.fiat.com
Other
134ms
24 KB
91%
€1/mo
Optional
www.fiat.com
www.fiat.com
Other
114ms
69 KB
63%
€1/mo
Optional
www.fiat.com
www.fiat.com
Other
87ms
50 KB
82%
€1/mo
Optional
cdnjs
cdnjs.cloudflare.com
CDN
84ms
28 KB
—
€1/mo
Optional
www.fiat.com
www.fiat.com
Other
78ms
2 KB
—
€1/mo
Optional
cookielaw.emea.fcagroup.com
cookielaw.emea.fcagroup.com
Other
71ms
5 KB
—
€1/mo
Optional
www.fiat.com
Other
Costly
Execution995ms
Transfer50 KB
Unused47%
Monthly Cost€11/mo
www.fiat.com
Other
Costly
Execution754ms
Transfer20 KB
Monthly Cost€8/mo
Google Tag Manager
Tag Manager
Costly
Execution419ms
Transfer130 KB
Unused50%
Monthly Cost€5/mo
www.fiat.com
Other
Costly
Execution341ms
Transfer4 KB
Monthly Cost€4/mo
Google Tag Manager
Tag Manager
Costly
Execution289ms
Transfer136 KB
Unused45%
Monthly Cost€3/mo
www.fiat.com
Other
Costly
Execution265ms
Transfer41 KB
Monthly Cost€3/mo
assets.adobedtm.com
Other
Optional
Execution180ms
Transfer70 KB
Unused31%
Monthly Cost€2/mo
www.fiat.com
Other
Optional
Execution179ms
Transfer95 KB
Unused46%
Monthly Cost€2/mo
www.fiat.com
Other
Optional
Execution170ms
Transfer3 KB
Monthly Cost€2/mo
www.fiat.com
Other
Optional
Execution162ms
Transfer54 KB
Monthly Cost€2/mo
www.fiat.com
Other
Optional
Execution134ms
Transfer24 KB
Unused91%
Monthly Cost€1/mo
www.fiat.com
Other
Optional
Execution114ms
Transfer69 KB
Unused63%
Monthly Cost€1/mo
www.fiat.com
Other
Optional
Execution87ms
Transfer50 KB
Unused82%
Monthly Cost€1/mo
cdnjs
CDN
Optional
Execution84ms
Transfer28 KB
Monthly Cost€1/mo
www.fiat.com
Other
Optional
Execution78ms
Transfer2 KB
Monthly Cost€1/mo
cookielaw.emea.fcagroup.com
Other
Optional
Execution71ms
Transfer5 KB
Monthly Cost€1/mo
These scripts may cost more than they're worth
www.fiat.com adds 995ms and costs ~€11/month
www.fiat.com adds 754ms and costs ~€8/month
Google Tag Manager adds 419ms and costs ~€5/month
www.fiat.com adds 341ms and costs ~€4/month
Google Tag Manager adds 289ms and costs ~€3/month
www.fiat.com adds 265ms and costs ~€3/month
92% 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
www.fiat.com takes 995ms 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
www.fiat.com takes 754ms 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
Google Tag Manager takes 419ms 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
www.fiat.com takes 341ms 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
Google Tag Manager takes 289ms 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
www.fiat.com takes 265ms 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
91% of www.fiat.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
63% of www.fiat.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
82% of www.fiat.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.