Performance
· 15 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.
564 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.28 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
0 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.001
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
940 ms
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
1.28 s
Page Load Progression
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BPage Weight Budget1.3 MB transferred, 43 requestsREVIEW
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
BThird-Party Impact52% third-party, 0 ms blockingREVIEW
CImage OptimizationAction16 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
BJS Execution Cost572ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://blog.youtube/ | 324ms | 4ms | 1ms | 1st |
| https://blog.youtube/static/youtube/js/6764.343636279b.min.js | 120ms | 16ms | 0ms | 1st |
| Unattributable | 76ms | 2ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-W8LC8VL | 52ms | 42ms | 10ms | 3rd |
BJS Bundles12 scripts, 118 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-8LV49FDYJ3&cx=c>m=4e64k0h1 | 144 KB | 62 KB (43%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-W8LC8VL | 128 KB | 56 KB (44%) | ✓ | 3rd |
| https://blog.youtube/static/blog_youtube/js/csp/gtm.js?version=pr20260415-1638 | 3 KB | — | ✓ | 1st |
| https://blog.youtube/static/youtube/js/all/index.js?version=pr20260415-1638 | 22 KB | — | ✓ | 1st |
| https://www.gstatic.com/glue/cookienotificationbar/cookienotificationbar.min.js | 28 KB | — | ✓ | 3rd |
| https://www.gstatic.com/external_hosted/vanillamasonry-v3_1_5/masonry.pkgd.min.js | 8 KB | — | ✓ | 3rd |
| https://blog.youtube/static/youtube/js/6764.343636279b.min.js | 4 KB | — | ✓ | 1st |
| https://blog.youtube/static/youtube/js/9947.1fac8a60f0.min.js | 5 KB | — | ✓ | 1st |
| https://blog.youtube/static/youtube/js/6605.45dbe0e706.min.js | 4 KB | — | ✓ | 1st |
| https://blog.youtube/static/youtube/js/7483.d6bac88413.min.js | 1 KB | — | ✓ | 1st |
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
CPage Weight InventoryAction43 resources · 1.3 MB · 118 KB savings availableREVIEW
~117.8 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 43 resources | 1.3 MiB | ||||||
A+Text CompressionAll text resources are compressedPASS
A+Font Loading8 fonts (237 KB)PASS
Web fonts
8
237 KB total
Render-blocking
0
of 8
Dominant font-display
swap
Most common across fonts
Font loading timeline
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 CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Google Cloud
Network Waterfall43 requests over 1161msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 76ms | 0 KB | — | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 52ms | 128 KB | 44% | $1/mo | Optional |