https://m.vueling.com/assets/img/home/social/insta... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/myvueling/push-ho... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/home/fly-with-us/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/home/social/twitt... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/home/fly-with-us/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/home/social/faceb... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/home/fly-with-us/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/home/logo-vueling... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/home/social/youtu... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://m.vueling.com/assets/img/home/app-store/an... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
34images667 KB
0oversized-0 KB
26legacy format
10missing 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
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
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW
Green Hosting
No green hosting detected
B
HTTP Caching
max-age=0
REVIEW
max-age=0
Info::
✓
Cache-Control header is set
Got: max-age=0
Info::
i
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control
max-age=0
Directive
Value
Meaning
max-age
0
Cache for 0 seconds
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
4 fonts (283 KB)
PASS
4 fonts (283 KB)
Info::
i
4 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
4
283 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
SourceSansPro-Regular.w...woff2swap
Size76 KB
Load time392 ms
Start1.3 s
RiskFOUT — text flashes from fallback to web font
SourceSansPro-SemiBold....woff2swap
Size75 KB
Load time160 ms
Start3.1 s
RiskFOUT — text flashes from fallback to web font
ds-vueling-icons.woff2woff2swap
Size109 KB
Load time323 ms
Start5.2 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
vuelingpilcrow-semibold...woff2swap
Size22 KB
Load time311 ms
Start5.2 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 ~55 KB and ~110 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
6 hints, 0 missing preconnects
PASS
6 hints, 0 missing preconnects
Info::
✓
Page uses 6 resource hint(s)
Current Resource Hints
preconnect
2
preload
1
dns-prefetch
3
prefetch—
6 resource hints configured
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
126 requests over 7608ms
INFO
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-party21013ms · 2727KB · €228/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
m.vueling.com
m.vueling.com
Other
5596ms
15 KB
—
€61/mo
Costly
m.vueling.com
m.vueling.com
Other
5403ms
57 KB
—
€59/mo
Costly
Unattributable
Unattributable
Other
2037ms
0 KB
—
€22/mo
Costly
m.vueling.com
m.vueling.com
Other
1530ms
736 KB
48%
€17/mo
Costly
m.vueling.com
m.vueling.com
Other
1058ms
153 KB
19%
€11/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
900ms
137 KB
47%
€10/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
605ms
147 KB
30%
€7/mo
Costly
m.vueling.com
m.vueling.com
Other
555ms
1 KB
21%
€6/mo
Costly
OneTrust
cdn.cookielaw.org
Consent
527ms
88 KB
52%
€6/mo
Essential
Google Tag Manager
www.googletagmanager.com
Tag Manager
523ms
199 KB
26%
€6/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
388ms
172 KB
33%
€4/mo
Costly
m.vueling.com
m.vueling.com
Other
350ms
155 KB
71%
€4/mo
Costly
f.monetate.net
f.monetate.net
Other
292ms
2 KB
—
€3/mo
Costly
OneTrust
cdn.cookielaw.org
Consent
208ms
132 KB
—
€2/mo
Essential
cdn.quantummetric.com
cdn.quantummetric.com
Other
199ms
155 KB
42%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
198ms
132 KB
45%
€2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
104ms
144 KB
45%
€1/mo
Optional
se.monetate.net
se.monetate.net
Other
103ms
64 KB
75%
€1/mo
Optional
OneTrust
cdn.cookielaw.org
Consent
102ms
7 KB
—
€1/mo
Essential
s.go-mpulse.net
s.go-mpulse.net
Other
94ms
56 KB
56%
€1/mo
Optional
m.vueling.com
m.vueling.com
Other
84ms
29 KB
—
€1/mo
Optional
f.monetate.net
f.monetate.net
Other
80ms
2 KB
—
€1/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
77ms
144 KB
74%
€1/mo
Optional
m.vueling.com
Other
Costly
Execution5596ms
Transfer15 KB
Monthly Cost€61/mo
m.vueling.com
Other
Costly
Execution5403ms
Transfer57 KB
Monthly Cost€59/mo
Unattributable
Other
Costly
Execution2037ms
Transfer0 KB
Monthly Cost€22/mo
m.vueling.com
Other
Costly
Execution1530ms
Transfer736 KB
Unused48%
Monthly Cost€17/mo
m.vueling.com
Other
Costly
Execution1058ms
Transfer153 KB
Unused19%
Monthly Cost€11/mo
Google Tag Manager
Tag Manager
Costly
Execution900ms
Transfer137 KB
Unused47%
Monthly Cost€10/mo
Google Tag Manager
Tag Manager
Costly
Execution605ms
Transfer147 KB
Unused30%
Monthly Cost€7/mo
m.vueling.com
Other
Costly
Execution555ms
Transfer1 KB
Unused21%
Monthly Cost€6/mo
OneTrust
Consent
Essential
Execution527ms
Transfer88 KB
Unused52%
Monthly Cost€6/mo
Google Tag Manager
Tag Manager
Costly
Execution523ms
Transfer199 KB
Unused26%
Monthly Cost€6/mo
Google Tag Manager
Tag Manager
Costly
Execution388ms
Transfer172 KB
Unused33%
Monthly Cost€4/mo
m.vueling.com
Other
Costly
Execution350ms
Transfer155 KB
Unused71%
Monthly Cost€4/mo
f.monetate.net
Other
Costly
Execution292ms
Transfer2 KB
Monthly Cost€3/mo
OneTrust
Consent
Essential
Execution208ms
Transfer132 KB
Monthly Cost€2/mo
cdn.quantummetric.com
Other
Optional
Execution199ms
Transfer155 KB
Unused42%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution198ms
Transfer132 KB
Unused45%
Monthly Cost€2/mo
Google Tag Manager
Tag Manager
Optional
Execution104ms
Transfer144 KB
Unused45%
Monthly Cost€1/mo
se.monetate.net
Other
Optional
Execution103ms
Transfer64 KB
Unused75%
Monthly Cost€1/mo
OneTrust
Consent
Essential
Execution102ms
Transfer7 KB
Monthly Cost€1/mo
s.go-mpulse.net
Other
Optional
Execution94ms
Transfer56 KB
Unused56%
Monthly Cost€1/mo
m.vueling.com
Other
Optional
Execution84ms
Transfer29 KB
Monthly Cost€1/mo
f.monetate.net
Other
Optional
Execution80ms
Transfer2 KB
Monthly Cost€1/mo
Google Tag Manager
Tag Manager
Optional
Execution77ms
Transfer144 KB
Unused74%
Monthly Cost€1/mo
These scripts may cost more than they're worth
m.vueling.com adds 5596ms and costs ~€61/month
m.vueling.com adds 5403ms and costs ~€59/month
Unattributable adds 2037ms and costs ~€22/month
m.vueling.com adds 1530ms and costs ~€17/month
m.vueling.com adds 1058ms and costs ~€11/month
Google Tag Manager adds 900ms and costs ~€10/month
Google Tag Manager adds 605ms and costs ~€7/month
m.vueling.com adds 555ms and costs ~€6/month
Google Tag Manager adds 523ms and costs ~€6/month
Google Tag Manager adds 388ms and costs ~€4/month
m.vueling.com adds 350ms and costs ~€4/month
f.monetate.net adds 292ms and costs ~€3/month
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
m.vueling.com takes 5596ms 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
m.vueling.com takes 5403ms 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
Unattributable takes 2037ms 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
m.vueling.com takes 1530ms 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
m.vueling.com takes 1058ms 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 900ms 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 605ms 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
m.vueling.com takes 555ms 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
52% of OneTrust'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 523ms 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 388ms 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
m.vueling.com takes 350ms 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 m.vueling.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
f.monetate.net takes 292ms 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
75% of se.monetate.net'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
56% of s.go-mpulse.net'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
74% 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.