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.
976 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.29 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
274 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.068
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.96 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.
4.65 s
Page Load Progression
FPage Weight BudgetAction4.0 MB transferred, 101 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
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
DJS BundlesAction59 scripts, 481 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.datacamp.com/_next/static/chunks/pages/_app-f7e9c71fee037706.js | 622 KB | 199 KB (34%) | ✓ | 3rd |
| https://accounts.google.com/gsi/client | 96 KB | 69 KB (72%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-0VFSSYW4KG&cx=c>m=4e64k0 | 167 KB | 64 KB (39%) | ✓ | 3rd |
| https://cdn.onesignal.com/sdks/OneSignalPageSDKES6.js?v=151607 | 69 KB | 60 KB (88%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TGGWB2P>m_auth=z30B2gnFx7YaJZsA-wGD8A>m_preview=env-2>m_cookies_win=x | 177 KB | 60 KB (34%) | ✓ | 3rd |
| https://www.datacamp.com/_next/static/chunks/framework-14a02dd5e036ebf0.js | 58 KB | 29 KB (51%) | ✓ | 3rd |
| https://www.datacamp.com/_next/static/VCN6wdJ4f36TAEfaV2Flz/_buildManifest.js | 5 KB | — | ✓ | 3rd |
| https://bat.bing.com/bat.js | 15 KB | — | ✓ | 3rd |
| https://www.datacamp.com/_next/static/chunks/86589.c2d18562d0900061.js | 1 KB | — | ✓ | 3rd |
| https://www.datacamp.com/_next/static/chunks/72815.978bf9cfc27095eb.js | 3 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 InventoryAction101 resources · 4.0 MB · 481 KB savings availableFIX
~480.9 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 101 resources | 4.0 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization19 images, 0 KB saveableREVIEW
CJS Execution CostAction1960ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.datacamp.com/ | 744ms | 2ms | 0ms | 3rd |
| https://www.datacamp.com/_next/static/chunks/framework-14a02dd5e036ebf0.js | 507ms | 475ms | 5ms | 3rd |
| https://www.datacamp.com/_next/static/chunks/pages/_app-f7e9c71fee037706.js | 252ms | 160ms | 65ms | 3rd |
| Unattributable | 171ms | 7ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TGGWB2P>m_auth=z30B2gnFx7YaJZsA-wGD8A>m_preview=env-2>m_cookies_win=x | 146ms | 112ms | 18ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-0VFSSYW4KG&cx=c>m=4e64k0 | 85ms | 73ms | 11ms | 3rd |
| https://www.datacamp.com/_next/static/chunks/pages/index-b2b0756740fcb913.js | 55ms | 52ms | 2ms | 3rd |
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 Loading3 fonts (46 KB)PASS
Web fonts
3
46 KB total
Render-blocking
0
of 3
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
Network Waterfall101 requests over 2953msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.datacamp.com www.datacamp.com | Other | 744ms | 129 KB | — | $10/mo | Costly |
www.datacamp.com www.datacamp.com | Other | 507ms | 58 KB | 51% | $7/mo | Costly |
www.datacamp.com www.datacamp.com | Other | 252ms | 622 KB | 34% | $3/mo | Costly |
Unattributable Unattributable | Other | 171ms | 0 KB | — | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 146ms | 177 KB | 34% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 85ms | 167 KB | 39% | $1/mo | Optional |
www.datacamp.com www.datacamp.com | Other | 55ms | 39 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.datacamp.com adds 744ms and costs ~$10/month
- www.datacamp.com adds 507ms and costs ~$7/month
- www.datacamp.com adds 252ms 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.datacamp.com takes 744ms 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
www.datacamp.com takes 507ms 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
51% of www.datacamp.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
www.datacamp.com takes 252ms 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