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.
2.49 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.24 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
80 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.190
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.96 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.
6.06 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 ImpactAction100% third-party, 0 ms blockingFIX
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization9 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
BJS Execution Cost852ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.slideserve.com/ | 403ms | 23ms | 4ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-534BDNWH21 | 268ms | 214ms | 53ms | 3rd |
| Unattributable | 181ms | 6ms | 0ms | 3rd |
BJS Bundles3 scripts, 65 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-534BDNWH21 | 157 KB | 65 KB (41%) | ✓ | 3rd |
| https://www.slideserve.com/assets/vendor/bootstrap/js/bootstrap.bundle.min.js | 23 KB | — | ✓ | 3rd |
| https://www.slideserve.com/assets/js/jquery.3.7.0.min.js | 30 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
APage Weight Budget945 KB transferred, 23 requestsPASS
A+Text CompressionAll text resources are compressedPASS
A+Font Loading2 fonts (56 KB)PASS
Web fonts
2
56 KB total
Render-blocking
0
of 2
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 Hints3 hints, 0 missing preconnectsPASS
Current Resource Hints
3 resource hints configured
APage Weight Inventory23 resources · 945 KB · 65 KB savings availablePASS
~64.9 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 23 resources | 944.8 KiB | ||||||
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall23 requests over 1921msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.slideserve.com www.slideserve.com | Other | 403ms | 18 KB | — | €4/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 268ms | 157 KB | 41% | €3/mo | Costly |
Unattributable Unattributable | Other | 181ms | 0 KB | — | €2/mo | Optional |
These scripts may cost more than they're worth
- www.slideserve.com adds 403ms and costs ~€4/month
- Google Tag Manager adds 268ms and costs ~€3/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.slideserve.com takes 403ms 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 268ms 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