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.
1.33 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.83 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
132 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.036
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.11 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.
4.32 s
Page Load Progression
FPage Weight BudgetAction3.7 MB transferred, 195 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
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 Execution CostAction2017ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.notion.com/ | 828ms | 23ms | 1ms | 3rd |
| https://www.notion.com/_next/static/chunks/framework-d8039d8c774492db.js | 526ms | 405ms | 3ms | 3rd |
| Unattributable | 346ms | 39ms | 0ms | 3rd |
| https://www.notion.com/_next/static/chunks/pages/_app-c7fee42076fc862b.js | 153ms | 95ms | 57ms | 3rd |
| https://www.notion.com/_next/static/chunks/sentry.next.7b192361210a9bb0.js | 108ms | 59ms | 31ms | 3rd |
| https://www.notion.com/_next/static/chunks/72678-7ff9da2b70602702.js | 56ms | 49ms | 6ms | 3rd |
FJS BundlesAction88 scripts, 1.8 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.notion.com/_next/static/chunks/sentry.next.7b192361210a9bb0.js | 192 KB | 171 KB (89%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/e96d881e-a2a503c1cb8af6df.js | 0 KB | 129 KB (60%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/e96d881e-a2a503c1cb8af6df.js | 68 KB | 129 KB (60%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/17270-15a2f22526fcd0ed.js | 0 KB | 113 KB (99%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/17270-15a2f22526fcd0ed.js | 41 KB | 113 KB (99%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/95503-1aa967ee7bce5b4e.js | 0 KB | 99 KB (57%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/95503-1aa967ee7bce5b4e.js | 67 KB | 99 KB (57%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/57222-d37bafd0bb80a046.js | 0 KB | 84 KB (74%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/57222-d37bafd0bb80a046.js | 39 KB | 84 KB (74%) | ✓ | 3rd |
| https://www.notion.com/_next/static/chunks/pages/_app-c7fee42076fc862b.js | 258 KB | 83 KB (32%) | ✓ | 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 InventoryAction195 resources · 3.7 MB · 1.8 MB savings availableFIX
~1.8 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 195 resources | 3.7 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization54 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 Loading6 fonts (163 KB)PASS
Web fonts
6
163 KB total
Render-blocking
0
of 6
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 Waterfall195 requests over 4236msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.notion.com www.notion.com | Other | 828ms | 58 KB | — | $11/mo | Costly |
www.notion.com www.notion.com | Other | 526ms | 46 KB | — | $7/mo | Costly |
Unattributable Unattributable | Other | 346ms | 0 KB | — | $5/mo | Costly |
www.notion.com www.notion.com | Other | 153ms | 258 KB | 32% | $2/mo | Optional |
www.notion.com www.notion.com | Other | 108ms | 192 KB | 89% | $1/mo | Optional |
www.notion.com www.notion.com | Other | 56ms | 0 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.notion.com adds 828ms and costs ~$11/month
- www.notion.com adds 526ms and costs ~$7/month
- Unattributable adds 346ms and costs ~$5/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.notion.com takes 828ms 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.notion.com takes 526ms 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 346ms 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
89% of www.notion.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