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
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.
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
4 fonts (298 KB)
PASS
4 fonts (298 KB)
Info::
i
4 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
4
298 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
cnn_sans_display-medium...woff2swap
Size46 KB
Load time16 ms
Start403 ms
RiskFOUT — text flashes from fallback to web font
cnn_sans_display-bold-v...woff2swap
Size47 KB
Load time19 ms
Start403 ms
RiskFOUT — text flashes from fallback to web font
cnn_sans_display-v1.woff2woff2swap
Size46 KB
Load time19 ms
Start404 ms
RiskFOUT — text flashes from fallback to web font
noto_serif-v1.woff2woff2swap
Size158 KB
Load time30 ms
Start404 ms
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
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 ~79 KB and ~158 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
No optimization needed
PASS
No optimization needed
Info::
✓
No resource hint issues
A+
HTTP/3 (QUIC)
HTTP/3 advertised via Alt-Svc
PASS
HTTP/3 advertised via Alt-Svc
Info::
✓
HTTP/3 (QUIC) is supported
First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.
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+
Main HTML Cache-Control
Main HTML max-age=60 (≤ 5min) is appropriate
PASS
Main HTML max-age=60 (≤ 5min) is appropriate
Info::
✓
Main HTML max-age=60 (≤ 5min) is appropriate
Got: max-age=60, public
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
JavaScript Blocking
1 JS blocking issue(s) detected
PASS
1 JS blocking issue(s) detected
Warning::
!
Total JS execution time is 7.4 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.
A+
CSS Performance Depth
No CSS performance depth issues detected
PASS
No CSS performance depth issues detected
Info::
✓
No CSS performance depth issues detected
A
HTTP Caching
max-age=60 (1 minute)
PASS
max-age=60 (1 minute)
Info::
✓
Cache-Control header is set
Got: max-age=60, public
Info::
✓
Effective TTL: 1 minute (max-age=60)
Info::
i
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control
max-age=60, public
Directive
Value
Meaning
max-age
60
Cache for 1 minute
public
—
Any cache may store this response
Effective TTL: 60 seconds
Network Waterfall
140 requests over 4683ms
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-party7372ms · 4936KB · $98/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
edition.cnn.com
edition.cnn.com
Other
2588ms
514 KB
—
$34/mo
Costly
Unattributable
Unattributable
Other
1185ms
0 KB
—
$16/mo
Costly
registry.api.cnn.io
registry.api.cnn.io
Other
587ms
654 KB
67%
$8/mo
Costly
registry.api.cnn.io
registry.api.cnn.io
Other
435ms
58 KB
60%
$6/mo
Costly
edition.cnn.com
edition.cnn.com
Other
415ms
216 KB
74%
$6/mo
Costly
cdn.tinypass.com
cdn.tinypass.com
Other
415ms
133 KB
63%
$6/mo
Costly
registry.api.cnn.io
registry.api.cnn.io
Other
301ms
2307 KB
11%
$4/mo
Costly
registry.api.cnn.io
registry.api.cnn.io
Other
270ms
363 KB
73%
$4/mo
Costly
lightning.cnn.com
lightning.cnn.com
Other
258ms
75 KB
—
$3/mo
Costly
Stripe
js.stripe.com
Payment
213ms
226 KB
73%
$3/mo
Essential
edition.cnn.com
edition.cnn.com
Other
183ms
44 KB
67%
$2/mo
Optional
Optimizely
cdn.optimizely.com
A/B Testing
138ms
121 KB
58%
$2/mo
Optional
cdn.cxense.com
cdn.cxense.com
Other
137ms
38 KB
59%
$2/mo
Optional
registry.api.cnn.io
registry.api.cnn.io
Other
103ms
61 KB
47%
$1/mo
Optional
edition.cnn.com
edition.cnn.com
Other
76ms
111 KB
74%
$1/mo
Optional
edition.cnn.com
edition.cnn.com
Other
68ms
18 KB
—
$1/mo
Optional
edition.cnn.com
Other
Costly
Execution2588ms
Transfer514 KB
Monthly Cost$34/mo
Unattributable
Other
Costly
Execution1185ms
Transfer0 KB
Monthly Cost$16/mo
registry.api.cnn.io
Other
Costly
Execution587ms
Transfer654 KB
Unused67%
Monthly Cost$8/mo
registry.api.cnn.io
Other
Costly
Execution435ms
Transfer58 KB
Unused60%
Monthly Cost$6/mo
edition.cnn.com
Other
Costly
Execution415ms
Transfer216 KB
Unused74%
Monthly Cost$6/mo
cdn.tinypass.com
Other
Costly
Execution415ms
Transfer133 KB
Unused63%
Monthly Cost$6/mo
registry.api.cnn.io
Other
Costly
Execution301ms
Transfer2307 KB
Unused11%
Monthly Cost$4/mo
registry.api.cnn.io
Other
Costly
Execution270ms
Transfer363 KB
Unused73%
Monthly Cost$4/mo
lightning.cnn.com
Other
Costly
Execution258ms
Transfer75 KB
Monthly Cost$3/mo
Stripe
Payment
Essential
Execution213ms
Transfer226 KB
Unused73%
Monthly Cost$3/mo
edition.cnn.com
Other
Optional
Execution183ms
Transfer44 KB
Unused67%
Monthly Cost$2/mo
Optimizely
A/B Testing
Optional
Execution138ms
Transfer121 KB
Unused58%
Monthly Cost$2/mo
cdn.cxense.com
Other
Optional
Execution137ms
Transfer38 KB
Unused59%
Monthly Cost$2/mo
registry.api.cnn.io
Other
Optional
Execution103ms
Transfer61 KB
Unused47%
Monthly Cost$1/mo
edition.cnn.com
Other
Optional
Execution76ms
Transfer111 KB
Unused74%
Monthly Cost$1/mo
edition.cnn.com
Other
Optional
Execution68ms
Transfer18 KB
Monthly Cost$1/mo
These scripts may cost more than they're worth
edition.cnn.com adds 2588ms and costs ~$34/month
Unattributable adds 1185ms and costs ~$16/month
registry.api.cnn.io adds 587ms and costs ~$8/month
registry.api.cnn.io adds 435ms and costs ~$6/month
edition.cnn.com adds 415ms and costs ~$6/month
cdn.tinypass.com adds 415ms and costs ~$6/month
registry.api.cnn.io adds 301ms and costs ~$4/month
registry.api.cnn.io adds 270ms and costs ~$4/month
lightning.cnn.com adds 258ms 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
edition.cnn.com takes 2588ms 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 1185ms 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
registry.api.cnn.io takes 587ms 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
67% of registry.api.cnn.io'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
registry.api.cnn.io takes 435ms 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
60% of registry.api.cnn.io'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
edition.cnn.com takes 415ms 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 edition.cnn.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.tinypass.com takes 415ms 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
63% of cdn.tinypass.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
registry.api.cnn.io takes 301ms 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
registry.api.cnn.io 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
73% of registry.api.cnn.io'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
lightning.cnn.com takes 258ms 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
73% of Stripe'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
67% of edition.cnn.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
58% of Optimizely'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
59% of cdn.cxense.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
74% of edition.cnn.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.
722 ms
1.4 s
2.2 s
2.9 s
5.1 s
5.8 s