Consider code splitting or tree shaking to reduce unused code.
Why this matters
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
Consider code splitting or tree shaking to reduce unused code.
Why this matters
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
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
1 fonts (111 KB)
PASS
1 fonts (111 KB)
Info::
i
1 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
1
111 KB total
Render-blocking
0
of 1
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
fa-solid-900.woff2woff2swap
Size111 KB
Load time569 ms
Start2.5 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
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
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
52 requests over 7132ms
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-party3801ms · 87KB · ¥188/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.bt.cn
www.bt.cn
Other
2990ms
20 KB
—
¥148/mo
Costly
Unattributable
Unattributable
Other
346ms
0 KB
—
¥17/mo
Costly
Microsoft Clarity
scripts.clarity.ms
Session Replay
284ms
26 KB
—
¥14/mo
Costly
hm.baidu.com
hm.baidu.com
Other
64ms
20 KB
—
¥3/mo
Optional
Bing UET
bat.bing.com
Advertising
59ms
15 KB
—
¥3/mo
Optional
www.bt.cn
www.bt.cn
Other
58ms
6 KB
—
¥3/mo
Optional
www.bt.cn
Other
Costly
Execution2990ms
Transfer20 KB
Monthly Cost¥148/mo
Unattributable
Other
Costly
Execution346ms
Transfer0 KB
Monthly Cost¥17/mo
Microsoft Clarity
Session Replay
Costly
Execution284ms
Transfer26 KB
Monthly Cost¥14/mo
hm.baidu.com
Other
Optional
Execution64ms
Transfer20 KB
Monthly Cost¥3/mo
Bing UET
Advertising
Optional
Execution59ms
Transfer15 KB
Monthly Cost¥3/mo
www.bt.cn
Other
Optional
Execution58ms
Transfer6 KB
Monthly Cost¥3/mo
These scripts may cost more than they're worth
www.bt.cn adds 2990ms and costs ~¥148/month
Unattributable adds 346ms and costs ~¥17/month
Microsoft Clarity adds 284ms and costs ~¥14/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.bt.cn takes 2990ms 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 346ms 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
Microsoft Clarity takes 284ms 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.