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.
2.93 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
10.05 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
2.86 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.414
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
5.66 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.
21.30 s
Page Load Progression
FPage Weight BudgetAction3.4 MB transferred, 100 requestsFIX
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
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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction8552ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.calm.com/_next/static/chunks/9a0d6000a621abbf.js | 3015ms | 2205ms | 32ms | 3rd |
| https://www.calm.com/ | 1293ms | 22ms | 82ms | 3rd |
| Unattributable | 835ms | 83ms | 0ms | 3rd |
| https://www.calm.com/api/12Xk43jk/init.js | 556ms | 519ms | 25ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-55DFT24 | 549ms | 452ms | 60ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-782291623&cx=c>m=4e64h1 | 388ms | 336ms | 40ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-N4F47DEEC3&cx=c&_slc=1 | 363ms | 307ms | 50ms | 3rd |
| https://www.calm.com/_next/static/chunks/86d1d098e04915b6.js | 344ms | 200ms | 13ms | 3rd |
| https://www.calm.com/_next/static/chunks/47af3fbf38360dab.js | 281ms | 252ms | 15ms | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 171ms | 134ms | 34ms | 3rd |
Showing top 10 of 19 scripts
FJS BundlesAction41 scripts, 504 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.calm.com/_next/static/chunks/6bcc3924f73ddcb7.js | 179 KB | 70 KB (39%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-N4F47DEEC3&cx=c&_slc=1 | 166 KB | 69 KB (41%) | ✓ | 3rd |
| https://www.calm.com/_next/static/chunks/9f12a3de7607ad3c.js | 132 KB | 65 KB (49%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-55DFT24 | 169 KB | 63 KB (37%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-782291623&cx=c>m=4e64h1 | 140 KB | 51 KB (36%) | ✓ | 3rd |
| https://www.calm.com/api/12Xk43jk/init.js | 0 KB | 40 KB (39%) | ✓ | 3rd |
| https://www.calm.com/api/12Xk43jk/init.js | 105 KB | 40 KB (39%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 97 KB | 35 KB (37%) | ✓ | 3rd |
| https://www.calm.com/_next/static/chunks/86d1d098e04915b6.js | 50 KB | 27 KB (54%) | ✓ | 3rd |
| https://www.calm.com/_next/static/chunks/9a0d6000a621abbf.js | 66 KB | 24 KB (36%) | ✓ | 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 InventoryAction100 resources · 3.4 MB · 504 KB savings availableFIX
~503.9 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 100 resources | 3.4 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization13 images, 0 KB saveableREVIEW
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 (70 KB)PASS
Web fonts
3
70 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
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall100 requests over 3458msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.calm.com www.calm.com | Other | 3015ms | 66 KB | 36% | $40/mo | Costly |
www.calm.com www.calm.com | Other | 1293ms | 127 KB | — | $17/mo | Costly |
Unattributable Unattributable | Other | 835ms | 0 KB | — | $11/mo | Costly |
www.calm.com www.calm.com | Other | 556ms | 0 KB | 39% | $7/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 549ms | 169 KB | 37% | $7/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 388ms | 140 KB | 36% | $5/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 363ms | 166 KB | 41% | $5/mo | Costly |
www.calm.com www.calm.com | Other | 344ms | 50 KB | 54% | $5/mo | Costly |
www.calm.com www.calm.com | Other | 281ms | 23 KB | — | $4/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 171ms | 97 KB | 37% | $2/mo | Optional |
truemed-public.s3.us-west-1.amazonaws.com truemed-public.s3.us-west-1.amazonaws.com | Other | 152ms | 22 KB | — | $2/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 125ms | 47 KB | 43% | $2/mo | Optional |
utt.impactcdn.com utt.impactcdn.com | Other | 95ms | 21 KB | — | $1/mo | Optional |
Segment cdn.segment.com | Analytics | 79ms | 1 KB | — | $1/mo | Optional |
Google Analytics www.google-analytics.com | Analytics | 74ms | 21 KB | — | $1/mo | Optional |
www.calm.com www.calm.com | Other | 65ms | 179 KB | 39% | $1/mo | Optional |
Segment cdn.segment.com | Analytics | 59ms | 30 KB | — | $1/mo | Optional |
websdk.appsflyer.com websdk.appsflyer.com | Other | 56ms | 16 KB | — | $1/mo | Optional |
cdn.mgln.ai cdn.mgln.ai | Other | 52ms | 3 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.calm.com adds 3015ms and costs ~$40/month
- www.calm.com adds 1293ms and costs ~$17/month
- Unattributable adds 835ms and costs ~$11/month
- www.calm.com adds 556ms and costs ~$7/month
- Google Tag Manager adds 549ms and costs ~$7/month
- Google Tag Manager adds 388ms and costs ~$5/month
- Google Tag Manager adds 363ms and costs ~$5/month
- www.calm.com adds 344ms and costs ~$5/month
- www.calm.com adds 281ms 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.calm.com takes 3015ms 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.calm.com takes 1293ms 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 835ms 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.calm.com takes 556ms 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 549ms 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 388ms 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 363ms 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.calm.com takes 344ms 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
54% of www.calm.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.calm.com takes 281ms 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