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.
1.48 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.05 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
510 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.
1.87 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.
4.21 s
Page Load Progression
375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s 2.6 s
3.0 sDThird-Party ImpactAction92% third-party, 0 ms blockingFIX
FJS Execution CostAction5375ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://assets-v2.slid.es/assets/marketing-c53fa6b3c542fa59a39ad05d7e6c6e152f7fab4824e400e9a89e04955a2ee90f.js | 2192ms | 199ms | 5ms | 3rd |
| https://slides.com/ | 2141ms | 15ms | 3ms | 1st |
| Unattributable | 584ms | 31ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-LWVDH9STBJ | 457ms | 370ms | 78ms | 3rd |
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization7 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
BJS Bundles2 scripts, 64 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-LWVDH9STBJ | 152 KB | 64 KB (42%) | ✓ | 3rd |
| https://assets-v2.slid.es/assets/marketing-c53fa6b3c542fa59a39ad05d7e6c6e152f7fab4824e400e9a89e04955a2ee90f.js | 10 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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Page Weight Budget617 KB transferred, 28 requestsPASS
A+Text CompressionAll text resources are compressedPASS
A+Font Loading1 fonts (47 KB)PASS
Web fonts
1
47 KB total
Render-blocking
0
of 1
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 Hints2 hints, 0 missing preconnectsPASS
Current Resource Hints
2 resource hints configured
APage Weight Inventory28 resources · 617 KB · 64 KB savings availablePASS
~64.2 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 28 resources | 616.8 KiB | ||||||
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall28 requests over 1449msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
assets-v2.slid.es assets-v2.slid.es | Other | 2192ms | 10 KB | — | €24/mo | Costly |
Unattributable Unattributable | Other | 584ms | 0 KB | — | €6/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 457ms | 152 KB | 42% | €5/mo | Costly |
These scripts may cost more than they're worth
- assets-v2.slid.es adds 2192ms and costs ~€24/month
- Unattributable adds 584ms and costs ~€6/month
- Google Tag Manager adds 457ms and costs ~€5/month
60% of JavaScript execution time comes from third-party scripts.
Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.
Learn more ▾ ▴
Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.
Source: web.dev / HTTP Archive Web Almanac
assets-v2.slid.es takes 2192ms 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 584ms 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
Google Tag Manager takes 457ms 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