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
32 images, 0 KB saveable
REVIEW
32 images, 0 KB saveable
Warning::
!
https://res.klook.com/image/upload/fl_lossy.progre... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://res.klook.com/image/upload/fl_lossy.progre... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://res.klook.com/image/upload/fl_lossy.progre... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://res.klook.com/image/upload/fl_lossy.progre... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://res.klook.com/image/upload/fl_lossy.progre... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://res.klook.com/image/upload/fl_lossy.progre... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://res.klook.com/image/upload/v1712803939/UED... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
32images896 KB
0oversized-0 KB
6legacy format
7missing 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
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
3 fonts (24 KB)
PASS
3 fonts (24 KB)
Info::
i
3 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
3
24 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
Poppins-Regular.woff2woff2swap
Size8 KB
Load time52 ms
Start1.0 s
RiskFOUT — text flashes from fallback to web font
Poppins-Medium.woff2woff2swap
Size8 KB
Load time45 ms
Start1.0 s
RiskFOUT — text flashes from fallback to web font
Poppins-SemiBold.woff2woff2swap
Size8 KB
Load time48 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)
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+
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
171 requests over 7972ms
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-party15792ms · 1581KB · $210/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
cdn.klook.com
cdn.klook.com
Other
2164ms
263 KB
57%
$29/mo
Costly
cdn.klook.com
cdn.klook.com
Other
2069ms
1 KB
—
$27/mo
Costly
www.klook.com
www.klook.com
Other
1710ms
56 KB
—
$23/mo
Costly
Unattributable
Unattributable
Other
1389ms
0 KB
—
$18/mo
Costly
cdn.klook.com
cdn.klook.com
Other
1305ms
67 KB
38%
$17/mo
Costly
ob.seseasky.com
ob.seseasky.com
Other
1096ms
45 KB
—
$15/mo
Costly
4263724d8cad.cdn4.forter.com
4263724d8cad.cdn4.forter.com
Other
949ms
184 KB
33%
$13/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
652ms
192 KB
39%
$9/mo
Costly
cdn.klook.com
cdn.klook.com
Other
624ms
6 KB
—
$8/mo
Costly
cdn.klook.com
cdn.klook.com
Other
482ms
48 KB
—
$6/mo
Costly
cdn.klook.com
cdn.klook.com
Other
449ms
233 KB
56%
$6/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
437ms
163 KB
48%
$6/mo
Costly
cdn.klook.com
cdn.klook.com
Other
432ms
14 KB
—
$6/mo
Costly
cdn.klook.com
cdn.klook.com
Other
386ms
11 KB
—
$5/mo
Costly
cdn.klook.com
cdn.klook.com
Other
270ms
2 KB
—
$4/mo
Costly
sp-trk.com
sp-trk.com
Other
268ms
6 KB
—
$4/mo
Costly
cdn.klook.com
cdn.klook.com
Other
262ms
186 KB
—
$3/mo
Costly
cdn.klook.com
cdn.klook.com
Other
224ms
2 KB
—
$3/mo
Costly
cdn.klook.com
cdn.klook.com
Other
178ms
40 KB
—
$2/mo
Optional
js.datadome.co
js.datadome.co
Other
168ms
39 KB
—
$2/mo
Optional
cdn.klook.com
cdn.klook.com
Other
143ms
2 KB
—
$2/mo
Optional
cdn.klook.com
cdn.klook.com
Other
84ms
6 KB
—
$1/mo
Optional
cdn.klook.com
cdn.klook.com
Other
50ms
14 KB
—
$1/mo
Optional
cdn.klook.com
Other
Costly
Execution2164ms
Transfer263 KB
Unused57%
Monthly Cost$29/mo
cdn.klook.com
Other
Costly
Execution2069ms
Transfer1 KB
Monthly Cost$27/mo
www.klook.com
Other
Costly
Execution1710ms
Transfer56 KB
Monthly Cost$23/mo
Unattributable
Other
Costly
Execution1389ms
Transfer0 KB
Monthly Cost$18/mo
cdn.klook.com
Other
Costly
Execution1305ms
Transfer67 KB
Unused38%
Monthly Cost$17/mo
ob.seseasky.com
Other
Costly
Execution1096ms
Transfer45 KB
Monthly Cost$15/mo
4263724d8cad.cdn4.forter.com
Other
Costly
Execution949ms
Transfer184 KB
Unused33%
Monthly Cost$13/mo
Google Tag Manager
Tag Manager
Costly
Execution652ms
Transfer192 KB
Unused39%
Monthly Cost$9/mo
cdn.klook.com
Other
Costly
Execution624ms
Transfer6 KB
Monthly Cost$8/mo
cdn.klook.com
Other
Costly
Execution482ms
Transfer48 KB
Monthly Cost$6/mo
cdn.klook.com
Other
Costly
Execution449ms
Transfer233 KB
Unused56%
Monthly Cost$6/mo
Google Tag Manager
Tag Manager
Costly
Execution437ms
Transfer163 KB
Unused48%
Monthly Cost$6/mo
cdn.klook.com
Other
Costly
Execution432ms
Transfer14 KB
Monthly Cost$6/mo
cdn.klook.com
Other
Costly
Execution386ms
Transfer11 KB
Monthly Cost$5/mo
cdn.klook.com
Other
Costly
Execution270ms
Transfer2 KB
Monthly Cost$4/mo
sp-trk.com
Other
Costly
Execution268ms
Transfer6 KB
Monthly Cost$4/mo
cdn.klook.com
Other
Costly
Execution262ms
Transfer186 KB
Monthly Cost$3/mo
cdn.klook.com
Other
Costly
Execution224ms
Transfer2 KB
Monthly Cost$3/mo
cdn.klook.com
Other
Optional
Execution178ms
Transfer40 KB
Monthly Cost$2/mo
js.datadome.co
Other
Optional
Execution168ms
Transfer39 KB
Monthly Cost$2/mo
cdn.klook.com
Other
Optional
Execution143ms
Transfer2 KB
Monthly Cost$2/mo
cdn.klook.com
Other
Optional
Execution84ms
Transfer6 KB
Monthly Cost$1/mo
cdn.klook.com
Other
Optional
Execution50ms
Transfer14 KB
Monthly Cost$1/mo
These scripts may cost more than they're worth
cdn.klook.com adds 2164ms and costs ~$29/month
cdn.klook.com adds 2069ms and costs ~$27/month
www.klook.com adds 1710ms and costs ~$23/month
Unattributable adds 1389ms and costs ~$18/month
cdn.klook.com adds 1305ms and costs ~$17/month
ob.seseasky.com adds 1096ms and costs ~$15/month
4263724d8cad.cdn4.forter.com adds 949ms and costs ~$13/month
Google Tag Manager adds 652ms and costs ~$9/month
cdn.klook.com adds 624ms and costs ~$8/month
cdn.klook.com adds 482ms and costs ~$6/month
cdn.klook.com adds 449ms and costs ~$6/month
Google Tag Manager adds 437ms and costs ~$6/month
cdn.klook.com adds 432ms and costs ~$6/month
cdn.klook.com adds 386ms and costs ~$5/month
cdn.klook.com adds 270ms and costs ~$4/month
sp-trk.com adds 268ms and costs ~$4/month
cdn.klook.com adds 262ms and costs ~$3/month
cdn.klook.com adds 224ms 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
cdn.klook.com takes 2164ms 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
57% of cdn.klook.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
cdn.klook.com takes 2069ms 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.klook.com takes 1710ms 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 1389ms 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
cdn.klook.com takes 1305ms 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
ob.seseasky.com takes 1096ms 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
4263724d8cad.cdn4.forter.com takes 949ms 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 652ms 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
cdn.klook.com takes 624ms 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
cdn.klook.com takes 482ms 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
cdn.klook.com takes 449ms 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
56% of cdn.klook.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 437ms 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
cdn.klook.com takes 432ms 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
cdn.klook.com takes 386ms 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
cdn.klook.com takes 270ms 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
sp-trk.com takes 268ms 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
cdn.klook.com takes 262ms 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
cdn.klook.com takes 224ms 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.