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.
3.99 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
13.61 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.26 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.064
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.52 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.
13.76 s
Page Load Progression
DPage Weight BudgetAction2.3 MB transferred, 73 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
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction3773ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.novartis.com/sites/novartiscom/files/js/js_RBDtWSKtcMyC24sM1Ge-XKAdIxxptpPPSBX0HfqcIdg.js?scope=footer&delta=0&language=en&theme=cosmos&include=eJx1kmuOpDAMhC8UiDRa7WpPYxlwhzRJjGzDdN9-zPRjXpo_wfU5FYVyUEbLI4wsFPGj7is2TDTBKReCbS2MkzfqWsgIaKdmh_RdU7jb1HhcwKuFJH4WAVXJILczjcYSz9q7Bf68_Pv7H3RmMTCSCtRmbCPV42w-gc0EMwnDjpLRWVbdCLhB5TCQuQfosrLebulSI27GoNtQs_22JVEjwRIGZlMTXGFAkcwxFR6wdGrXklsKI_OSaRWOz8qZVtb4tD7AD-s7bbt2uXqKXcJSSK6PhhbP5SH2PBF3a8FrV7JamNDQhWc40Ix7ZtFAF_ODlzjJtmLp7zIk5uTTMUwx-fJd93jGy1dYQxuhYEubXwuUym0iTzLy1kyuz05Q8lHNgGuGI9vHC4i_8PD-N0B18MQXLLYJxvv3RsMrQaWEPuUtnlhq_0rdAbqDdCfhZtSmN6ZXBd0&0=tdwrnx | 1038ms | 521ms | 99ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-57RJQ5 | 658ms | 527ms | 80ms | 3rd |
| Unattributable | 626ms | 140ms | 0ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202604.1.0/otBannerSdk.js | 416ms | 293ms | 65ms | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 380ms | 325ms | 23ms | 3rd |
| https://www.novartis.com/ | 355ms | 8ms | 2ms | 3rd |
| https://www.novartis.com/sites/novartiscom/files/css/css_QXAvsP_9ka40oU06UbzMmrv3v4aToOZDlZcBKmTiVWw.css?delta=3&language=en&theme=cosmos&include=eJx1kFtuAyEMRTfEzEhNpS7HMuDM0AGMbNMkuy959iPqF_j4dX1RlQxS_aZgLEtQnVECfB6-Pg7ghXeq0DDGVFfgI9hGcEwVa0iYQUh7NgVDn8l5MiMBOjdWiqMsj1CXlSoJZueZTU2wgUeRxMuRpbzTNbPHPKld8tjpAmthXbLJ81vGyjQp5aF4isIt8qk-k5pT2B2dbTTvS5TeMM-P0NUAGevacSW494-LXyRwryaXV8Y1FFyHsk2fg_7I3GvrPifdKDqlYdkG2BJgNw5cWiaj5R_ulG_uFYoJ4aps6H5D87C6jNqLGpXFo5L7SZEYqPjh7o7ZuuDyeO_UnWiMWLFQ7Td75xNNVzBdyXQUrkY1_gI1vcVa&0=tdwrnx | 110ms | 0ms | 0ms | 3rd |
| https://script.crazyegg.com/pages/versioned/tracking-scripts/158692313dc4b9f2e28d9e9025e38d6b.js | 75ms | 65ms | 9ms | 3rd |
| https://static.ads-twitter.com/uwt.js | 64ms | 57ms | 6ms | 3rd |
| https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da1771523124516 | 52ms | 30ms | 5ms | 3rd |
DPage Weight InventoryAction73 resources · 2.3 MB · 275 KB savings availableFIX
~275.5 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 73 resources | 2.3 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction28 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
CJS BundlesAction17 scripts, 275 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.novartis.com/sites/novartiscom/files/js/js_RBDtWSKtcMyC24sM1Ge-XKAdIxxptpPPSBX0HfqcIdg.js?scope=footer&delta=0&language=en&theme=cosmos&include=eJx1kmuOpDAMhC8UiDRa7WpPYxlwhzRJjGzDdN9-zPRjXpo_wfU5FYVyUEbLI4wsFPGj7is2TDTBKReCbS2MkzfqWsgIaKdmh_RdU7jb1HhcwKuFJH4WAVXJILczjcYSz9q7Bf68_Pv7H3RmMTCSCtRmbCPV42w-gc0EMwnDjpLRWVbdCLhB5TCQuQfosrLebulSI27GoNtQs_22JVEjwRIGZlMTXGFAkcwxFR6wdGrXklsKI_OSaRWOz8qZVtb4tD7AD-s7bbt2uXqKXcJSSK6PhhbP5SH2PBF3a8FrV7JamNDQhWc40Ix7ZtFAF_ODlzjJtmLp7zIk5uTTMUwx-fJd93jGy1dYQxuhYEubXwuUym0iTzLy1kyuz05Q8lHNgGuGI9vHC4i_8PD-N0B18MQXLLYJxvv3RsMrQaWEPuUtnlhq_0rdAbqDdCfhZtSmN6ZXBd0&0=tdwrnx | 184 KB | 123 KB (67%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202604.1.0/otBannerSdk.js | 131 KB | 69 KB (53%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-57RJQ5 | 183 KB | 56 KB (31%) | ✓ | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 55 KB | 27 KB (49%) | ✓ | 3rd |
| https://www.youtube.com/s/player/22f02d3d/www-widgetapi.vflset/www-widgetapi.js | 11 KB | — | ✓ | 3rd |
| https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da1771523124516 | 11 KB | — | ✓ | 3rd |
| https://cdn.cookielaw.org/consent/fe8dfb2c-2701-45db-8577-13675c68ed60/OtAutoBlock.js | 13 KB | — | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/otSDKStub.js | 9 KB | — | ✓ | 3rd |
| https://www.novartis.com/sites/novartiscom/files/js/js_XxhNeXYR2zsyBLpDKl7qUQpBCSmEQJy7w8HBap0vrUg.js?scope=header&delta=0&language=en&theme=cosmos&include=eJx1kmuOpDAMhC8UiDRa7WpPYxlwhzRJjGzDdN9-zPRjXpo_wfU5FYVyUEbLI4wsFPGj7is2TDTBKReCbS2MkzfqWsgIaKdmh_RdU7jb1HhcwKuFJH4WAVXJILczjcYSz9q7Bf68_Pv7H3RmMTCSCtRmbCPV42w-gc0EMwnDjpLRWVbdCLhB5TCQuQfosrLebulSI27GoNtQs_22JVEjwRIGZlMTXGFAkcwxFR6wdGrXklsKI_OSaRWOz8qZVtb4tD7AD-s7bbt2uXqKXcJSSK6PhhbP5SH2PBF3a8FrV7JamNDQhWc40Ix7ZtFAF_ODlzjJtmLp7zIk5uTTMUwx-fJd93jGy1dYQxuhYEubXwuUym0iTzLy1kyuz05Q8lHNgGuGI9vHC4i_8PD-N0B18MQXLLYJxvv3RsMrQaWEPuUtnlhq_0rdAbqDdCfhZtSmN6ZXBd0&0=tdwrnx | 0 KB | — | ✓ | 3rd |
| https://www.novartis.com/modules/contrib/google_tag/js/gtm.js?tdwrnx | 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
A+Text CompressionAll text resources are compressedPASS
A+Font Loading3 fonts (104 KB)PASS
Web fonts
3
104 KB total
Render-blocking
0
of 3
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
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 ~31 KB and ~62 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints1 hints, 0 missing preconnectsPASS
Current Resource Hints
1 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall73 requests over 1548msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.novartis.com www.novartis.com | Other | 1038ms | 184 KB | 67% | €11/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 658ms | 183 KB | 31% | €7/mo | Costly |
Unattributable Unattributable | Other | 626ms | 0 KB | — | €7/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 416ms | 131 KB | 53% | €5/mo | Essential |
script.crazyegg.com script.crazyegg.com | Other | 380ms | 55 KB | 49% | €4/mo | Costly |
www.novartis.com www.novartis.com | Other | 355ms | 29 KB | — | €4/mo | Costly |
www.novartis.com www.novartis.com | Other | 110ms | 288 KB | — | €1/mo | Optional |
script.crazyegg.com script.crazyegg.com | Other | 75ms | 23 KB | — | €1/mo | Optional |
Twitter/X Pixel static.ads-twitter.com | Advertising | 64ms | 13 KB | — | €1/mo | Optional |
static.cloudflareinsights.com static.cloudflareinsights.com | Other | 52ms | 11 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- www.novartis.com adds 1038ms and costs ~€11/month
- Google Tag Manager adds 658ms and costs ~€7/month
- Unattributable adds 626ms and costs ~€7/month
- script.crazyegg.com adds 380ms and costs ~€4/month
- www.novartis.com adds 355ms and costs ~€4/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.novartis.com takes 1038ms 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
67% of www.novartis.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 658ms 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 626ms 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
53% of OneTrust'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
script.crazyegg.com takes 380ms 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.novartis.com takes 355ms 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