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
Page Weight Budget
Action
1.6 MB transferred, 50 requests
REVIEW
1.6 MB transferred, 50 requests
Info::
i
Page weighs 5.0 MB (1.6 MB transferred)
Warning::
!
JavaScript is 1.3 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.3 MB
Info::
✓
50 HTTP requests
Info::
i
Estimated 0.33 g CO2 per page load
1.6 MBtransferred
50 requests
0.33 g CO2 per page load
JavaScript1.3 MiB84%
Fonts124.9 KiB8%
CSS38.6 KiB2%
Other36.8 KiB2%
Images36.6 KiB2%
HTML16.7 KiB1%
Other1.5 KiB0%
Other712 B0%
Other562 B0%
Other560 B0%
Other0 B0%
02.4 MB4.9 MB
Approaching limit
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Why this matters
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
B
Image Optimization
3 images, 0 KB saveable
REVIEW
3 images, 0 KB saveable
Warning::
!
https://cdn.worldometers.info/img/worldometers-log... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
3images37 KB
0oversized-0 KB
3legacy 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
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 (125 KB)
PASS
3 fonts (125 KB)
Info::
i
3 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
3
125 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
normal.woff2woff2swap
Size48 KB
Load time44 ms
Start819 ms
RiskFOUT — text flashes from fallback to web font
normal.woff2woff2swap
Size35 KB
Load time57 ms
Start820 ms
RiskFOUT — text flashes from fallback to web font
memvYaGs126MiZpBA-UvWbX...woff2swap
Size42 KB
Load time94 ms
Start4.5 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
10 hints, 0 missing preconnects
PASS
10 hints, 0 missing preconnects
Info::
✓
Page uses 10 resource hint(s)
Current Resource Hints
preconnect
9
preload—
dns-prefetch—
prefetch
1
10 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
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall
50 requests over 5484ms
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-party21443ms · 1173KB · $370/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
Unattributable
Unattributable
Other
13033ms
0 KB
—
$225/mo
Costly
code.jquery.com
code.jquery.com
Other
3764ms
30 KB
—
$65/mo
Costly
www.worldometers.info
www.worldometers.info
Other
2317ms
17 KB
—
$40/mo
Costly
fundingchoicesmessages.google.com
fundingchoicesmessages.google.com
Other
372ms
66 KB
—
$6/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
365ms
158 KB
39%
$6/mo
Costly
www.worldometers.info
www.worldometers.info
Other
286ms
0 KB
—
$5/mo
Costly
fundingchoicesmessages.google.com
fundingchoicesmessages.google.com
Other
209ms
70 KB
52%
$4/mo
Costly
securepubads.g.doubleclick.net
securepubads.g.doubleclick.net
Other
183ms
188 KB
77%
$3/mo
Optional
a.pub.network
a.pub.network
Other
173ms
186 KB
82%
$3/mo
Optional
cdn.worldometers.info
cdn.worldometers.info
Other
167ms
6 KB
—
$3/mo
Optional
pagead2.googlesyndication.com
pagead2.googlesyndication.com
Other
136ms
178 KB
84%
$2/mo
Optional
a.pub.network
a.pub.network
Other
135ms
160 KB
82%
$2/mo
Optional
securepubads.g.doubleclick.net
securepubads.g.doubleclick.net
Other
103ms
34 KB
71%
$2/mo
Optional
pagead2.googlesyndication.com
pagead2.googlesyndication.com
Other
101ms
54 KB
52%
$2/mo
Optional
a.pub.network
a.pub.network
Other
99ms
26 KB
—
$2/mo
Optional
Unattributable
Other
Costly
Execution13033ms
Transfer0 KB
Monthly Cost$225/mo
code.jquery.com
Other
Costly
Execution3764ms
Transfer30 KB
Monthly Cost$65/mo
www.worldometers.info
Other
Costly
Execution2317ms
Transfer17 KB
Monthly Cost$40/mo
fundingchoicesmessages.google.com
Other
Costly
Execution372ms
Transfer66 KB
Monthly Cost$6/mo
Google Tag Manager
Tag Manager
Costly
Execution365ms
Transfer158 KB
Unused39%
Monthly Cost$6/mo
www.worldometers.info
Other
Costly
Execution286ms
Transfer0 KB
Monthly Cost$5/mo
fundingchoicesmessages.google.com
Other
Costly
Execution209ms
Transfer70 KB
Unused52%
Monthly Cost$4/mo
securepubads.g.doubleclick.net
Other
Optional
Execution183ms
Transfer188 KB
Unused77%
Monthly Cost$3/mo
a.pub.network
Other
Optional
Execution173ms
Transfer186 KB
Unused82%
Monthly Cost$3/mo
cdn.worldometers.info
Other
Optional
Execution167ms
Transfer6 KB
Monthly Cost$3/mo
pagead2.googlesyndication.com
Other
Optional
Execution136ms
Transfer178 KB
Unused84%
Monthly Cost$2/mo
a.pub.network
Other
Optional
Execution135ms
Transfer160 KB
Unused82%
Monthly Cost$2/mo
securepubads.g.doubleclick.net
Other
Optional
Execution103ms
Transfer34 KB
Unused71%
Monthly Cost$2/mo
pagead2.googlesyndication.com
Other
Optional
Execution101ms
Transfer54 KB
Unused52%
Monthly Cost$2/mo
a.pub.network
Other
Optional
Execution99ms
Transfer26 KB
Monthly Cost$2/mo
These scripts may cost more than they're worth
Unattributable adds 13033ms and costs ~$225/month
code.jquery.com adds 3764ms and costs ~$65/month
www.worldometers.info adds 2317ms and costs ~$40/month
fundingchoicesmessages.google.com adds 372ms and costs ~$6/month
Google Tag Manager adds 365ms and costs ~$6/month
www.worldometers.info adds 286ms and costs ~$5/month
fundingchoicesmessages.google.com adds 209ms and costs ~$4/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
Unattributable takes 13033ms 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
code.jquery.com takes 3764ms 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.worldometers.info takes 2317ms 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
fundingchoicesmessages.google.com takes 372ms 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 365ms 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.worldometers.info takes 286ms 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
fundingchoicesmessages.google.com takes 209ms 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 fundingchoicesmessages.google.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
77% of securepubads.g.doubleclick.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
82% of a.pub.network'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
84% of pagead2.googlesyndication.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 a.pub.network'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
71% of securepubads.g.doubleclick.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
52% of pagead2.googlesyndication.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.