Performance
· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
7.94 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
53.07 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
580 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.002
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
8.06 s
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
53.10 s
Page Load Progression
FPage Weight BudgetAction38.8 MB transferred, 158 requestsFIX
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
Subset fonts to include only used characters, or switch to system font stacks.
Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).
Source: web.dev font loading
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction3783ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.cgtn.com/ | 892ms | 6ms | 2ms | 3rd |
| https://ui.cgtn.com/static/ng/resource/vendor/jquery.min.js | 890ms | 535ms | 6ms | 3rd |
| Unattributable | 873ms | 6ms | 0ms | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 327ms | 260ms | 14ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-Q2N7DKTSVJ | 241ms | 198ms | 41ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-KWDZVQ2 | 161ms | 110ms | 26ms | 3rd |
| https://ui.cgtn.com/static/ng/resource/vendor/lazysizes.min.js | 152ms | 53ms | 1ms | 3rd |
| https://www.googleoptimize.com/optimize.js?id=OPT-T2F4KMW | 122ms | 89ms | 22ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-Q2N7DKTSVJ&cx=c>m=4e64h1 | 72ms | 20ms | 52ms | 3rd |
| https://ui.cgtn.com/static/ng/resource/website/js/ng-home-v4-4.2.2.js?t=20210521 | 55ms | 24ms | 31ms | 3rd |
DJS BundlesAction20 scripts, 430 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-Q2N7DKTSVJ&cx=c>m=4e64h1 | 170 KB | 114 KB (67%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-Q2N7DKTSVJ | 170 KB | 69 KB (41%) | ✓ | 3rd |
| https://www.googleoptimize.com/optimize.js?id=OPT-T2F4KMW | 109 KB | 65 KB (60%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-KWDZVQ2 | 125 KB | 62 KB (49%) | ✓ | 3rd |
| https://ui.cgtn.com/static/ng/resource/vendor/jwplayer/jwplayer.js | 61 KB | 51 KB (84%) | ✓ | 3rd |
| https://ui.cgtn.com/static/ng/resource/website/js/ng-home-v4-4.2.2.js?t=20210521 | 52 KB | 40 KB (77%) | ✓ | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 55 KB | 30 KB (54%) | ✓ | 3rd |
| https://ui.cgtn.com/static/ng/resource/vendor/swiper-6.1.2/swiper.min.js | 35 KB | — | ✓ | 3rd |
| https://ui.cgtn.com/static/ng/resource/vendor/floatPlayer/js/floatPlayer.js | 3 KB | — | ✓ | 3rd |
| https://global-ui.cgtn.com/static/public/web_share/js/location.js | 1 KB | — | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
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.
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.
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.
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.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
FPage Weight InventoryAction158 resources · 38.8 MB · 430 KB savings availableFIX
~430.3 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 158 resources | 38.8 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction111 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
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.
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.
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.
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.
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.
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.
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.
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.
Performance issues directly impact user engagement and conversion rates.
Set explicit width and height to prevent CLS.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font Loading7 fonts (696 KB)PASS
Web fonts
7
696 KB total
Render-blocking
0
of 7
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Convert to woff2 for ~30% smaller file size
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Convert to woff2 for ~30% smaller file size
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Convert to woff2 for ~30% smaller file size
- 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 ~492 KB and ~984 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall158 requests over 2025msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.cgtn.com www.cgtn.com | Other | 892ms | 388 KB | — | ¥25/mo | Costly |
ui.cgtn.com ui.cgtn.com | Other | 890ms | 30 KB | — | ¥25/mo | Costly |
Unattributable Unattributable | Other | 873ms | 0 KB | — | ¥25/mo | Costly |
script.crazyegg.com script.crazyegg.com | Other | 327ms | 55 KB | 54% | ¥9/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 241ms | 170 KB | 41% | ¥7/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 161ms | 125 KB | 49% | ¥5/mo | Optional |
ui.cgtn.com ui.cgtn.com | Other | 152ms | 4 KB | — | ¥4/mo | Optional |
www.googleoptimize.com www.googleoptimize.com | Other | 122ms | 109 KB | 60% | ¥3/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 72ms | 170 KB | 67% | ¥2/mo | Optional |
ui.cgtn.com ui.cgtn.com | Other | 55ms | 52 KB | 77% | ¥2/mo | Optional |
These scripts may cost more than they're worth
- www.cgtn.com adds 892ms and costs ~¥25/month
- ui.cgtn.com adds 890ms and costs ~¥25/month
- Unattributable adds 873ms and costs ~¥25/month
- script.crazyegg.com adds 327ms and costs ~¥9/month
- Google Tag Manager adds 241ms and costs ~¥7/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
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.cgtn.com takes 892ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
ui.cgtn.com takes 890ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Unattributable takes 873ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
script.crazyegg.com takes 327ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
54% of script.crazyegg.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
Google Tag Manager takes 241ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
60% of www.googleoptimize.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
67% of Google Tag Manager's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
77% of ui.cgtn.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev