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
30 images, 0 KB saveable
REVIEW
30 images, 0 KB saveable
Warning::
!
https://cdn-www.bluestacks.com/bs-images/logo-icon... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://cdn-www.bluestacks.com/bs-images/logo-text... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
30images1.9 MB
0oversized-0 KB
29legacy format
2missing 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
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
5 fonts (66 KB)
PASS
5 fonts (66 KB)
Info::
i
5 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
5
66 KB total
Render-blocking
0
of 5
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
JTUSjIg1_i6t8kCHKm459Wl...woff2swap
Size35 KB
Load time9 ms
Start324 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLCz7Z1x...woff2swap
Size8 KB
Load time11 ms
Start447 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLEj6Z1x...woff2swap
Size8 KB
Load time13 ms
Start448 ms
RiskFOUT — text flashes from fallback to web font
pxiEyp8kv8JHgFVrJJfecnF...woff2swap
Size8 KB
Load time14 ms
Start449 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLGT9Z1x...woff2swap
Size8 KB
Load time13 ms
Start449 ms
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
4 hints, 0 missing preconnects
PASS
4 hints, 0 missing preconnects
Info::
✓
Page uses 4 resource hint(s)
Current Resource Hints
preconnect
3
preload—
dns-prefetch
1
prefetch—
4 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
79 requests over 4284ms
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-party7177ms · 1228KB · R$636/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.bluestacks.com
www.bluestacks.com
Other
3578ms
137 KB
—
R$317/mo
Costly
cmp.inmobi.com
cmp.inmobi.com
Other
657ms
123 KB
47%
R$58/mo
Costly
cmp.inmobi.com
cmp.inmobi.com
Other
643ms
114 KB
50%
R$57/mo
Costly
Unattributable
Unattributable
Other
635ms
0 KB
—
R$56/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
561ms
167 KB
36%
R$50/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
373ms
172 KB
40%
R$33/mo
Costly
www.bluestacks.com
www.bluestacks.com
Other
356ms
237 KB
74%
R$31/mo
Costly
www.bluestacks.com
www.bluestacks.com
Other
220ms
86 KB
71%
R$20/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
100ms
172 KB
66%
R$9/mo
Optional
www.bluestacks.com
www.bluestacks.com
Other
54ms
21 KB
—
R$5/mo
Optional
www.bluestacks.com
Other
Costly
Execution3578ms
Transfer137 KB
Monthly CostR$317/mo
cmp.inmobi.com
Other
Costly
Execution657ms
Transfer123 KB
Unused47%
Monthly CostR$58/mo
cmp.inmobi.com
Other
Costly
Execution643ms
Transfer114 KB
Unused50%
Monthly CostR$57/mo
Unattributable
Other
Costly
Execution635ms
Transfer0 KB
Monthly CostR$56/mo
Google Tag Manager
Tag Manager
Costly
Execution561ms
Transfer167 KB
Unused36%
Monthly CostR$50/mo
Google Tag Manager
Tag Manager
Costly
Execution373ms
Transfer172 KB
Unused40%
Monthly CostR$33/mo
www.bluestacks.com
Other
Costly
Execution356ms
Transfer237 KB
Unused74%
Monthly CostR$31/mo
www.bluestacks.com
Other
Costly
Execution220ms
Transfer86 KB
Unused71%
Monthly CostR$20/mo
Google Tag Manager
Tag Manager
Optional
Execution100ms
Transfer172 KB
Unused66%
Monthly CostR$9/mo
www.bluestacks.com
Other
Optional
Execution54ms
Transfer21 KB
Monthly CostR$5/mo
These scripts may cost more than they're worth
www.bluestacks.com adds 3578ms and costs ~R$317/month
cmp.inmobi.com adds 657ms and costs ~R$58/month
cmp.inmobi.com adds 643ms and costs ~R$57/month
Unattributable adds 635ms and costs ~R$56/month
Google Tag Manager adds 561ms and costs ~R$50/month
Google Tag Manager adds 373ms and costs ~R$33/month
www.bluestacks.com adds 356ms and costs ~R$31/month
www.bluestacks.com adds 220ms and costs ~R$20/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
www.bluestacks.com takes 3578ms 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
cmp.inmobi.com takes 657ms 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
cmp.inmobi.com takes 643ms 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 635ms 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 561ms 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 373ms 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.bluestacks.com takes 356ms 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
74% of www.bluestacks.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
www.bluestacks.com takes 220ms 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 www.bluestacks.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
66% 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.