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https://www.notion.so

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
70
GRADE
C
FIX
5
REVIEW
2
PASS
5
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
31
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
92
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

3.59 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

7.10 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

2.81 s

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.000

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

10.47 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.

20.80 s

Page Load Progression

954 ms
1.9 s
2.9 s
3.8 s
4.8 s
5.7 s
6.7 s
7.6 s
Checks
14
5 PASS 2 REVIEW 5 FIX
D
Page Weight Budget
Action
2.5 MB transferred, 184 requests
FIX
2.5 MB transferred, 184 requests
Warning::
Page weighs 8.6 MB (2.5 MB transferred)
Warning::
JavaScript is 1.2 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.2 MB
Warning::
184 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.52 g CO2 per page load
2.5 MB / 2.4 MB budget
2.5 MB transferred
184 requests
0.52 g CO2 per page load
JavaScript 1.2 MiB 46%
Other 489.5 KiB 19%
Images 350.0 KiB 14%
Other 190.1 KiB 7%
Fonts 163.2 KiB 6%
CSS 116.1 KiB 5%
HTML 57.7 KiB 2%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

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.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (2.5 MiB of 2.5 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
18939ms total JS execution
FIX
18939ms total JS execution
Warning::
https://www.notion.com/_next/static/chunks/sentry....: 8260ms CPU time
Warning::
https://www.notion.com/_next/static/chunks/framewo...: 3062ms CPU time
Warning::
https://www.notion.com/: 2455ms CPU time
Warning::
Unattributable: 2311ms CPU time
Warning::
https://www.notion.com/_next/static/chunks/pages/_...: 659ms CPU time
Warning::
Third-party scripts: 18939ms (100% of total)

Main Thread Breakdown

Style & Layout 30% Script Evaluation 29% Other 26% Rendering 7% Script Parsing & Compilation 6%
ScriptTotalScriptingParse/CompileParty
https://www.notion.com/_next/static/chunks/sentry.next.be9c9dd35e340856.js8260ms771ms175ms3rd
https://www.notion.com/_next/static/chunks/framework-23933e8b27fffebb.js3062ms2299ms29ms3rd
https://www.notion.com/2455ms195ms4ms3rd
Unattributable2311ms251ms0ms3rd
https://www.notion.com/_next/static/chunks/pages/_app-1ba900149c08adf4.js659ms452ms202ms3rd
https://www.notion.com/_next/static/chunks/72678-7ff9da2b70602702.js383ms334ms47ms3rd
https://transcend-cdn.com/cm/a36a42ad-3a71-444f-9e8a-b19950129dc6/ui.js370ms310ms58ms3rd
https://transcend-cdn.com/cm/a36a42ad-3a71-444f-9e8a-b19950129dc6/airgap.js264ms231ms23ms3rd
https://www.notion.com/_next/static/chunks/main-9070ba6adf5df692.js245ms204ms27ms3rd
https://www.notion.com/_next/static/chunks/pages/product-b7657f40f3492409.js222ms220ms1ms3rd

Showing top 10 of 17 scripts

F
JS Bundles
Action
88 scripts, 1.9 MB unused
FIX
88 scripts, 1.9 MB unused
Warning::
https://www.notion.com/_next/static/chunks/sentry....: 171 KB unused (89%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.notion.com/_next/static/chunks/e96d881...: 129 KB unused (60%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.notion.com/_next/static/chunks/e96d881...: 129 KB unused (60%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.notion.com/_next/static/chunks/17270-b...: 113 KB unused (99%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.notion.com/_next/static/chunks/17270-b...: 113 KB unused (99%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.9 MB
1911 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.notion.com/_next/static/chunks/sentry.next.be9c9dd35e340856.js192 KB171 KB (89%)✓3rd
https://www.notion.com/_next/static/chunks/e96d881e-a2a503c1cb8af6df.js0 KB129 KB (60%)✓3rd
https://www.notion.com/_next/static/chunks/e96d881e-a2a503c1cb8af6df.js68 KB129 KB (60%)✓3rd
https://www.notion.com/_next/static/chunks/17270-bf2dfc8416258a85.js41 KB113 KB (99%)✓3rd
https://www.notion.com/_next/static/chunks/17270-bf2dfc8416258a85.js0 KB113 KB (99%)✓3rd
https://www.notion.com/_next/static/chunks/95503-1aa967ee7bce5b4e.js0 KB99 KB (57%)✓3rd
https://www.notion.com/_next/static/chunks/95503-1aa967ee7bce5b4e.js67 KB99 KB (57%)✓3rd
https://www.notion.com/_next/static/chunks/pages/_app-1ba900149c08adf4.js252 KB80 KB (32%)✓3rd
https://www.notion.com/_next/static/chunks/pages/product/%5Bslug%5D-ff524b0bb483a545.js28 KB69 KB (76%)✓3rd
https://www.notion.com/_next/static/chunks/pages/product/%5Bslug%5D-ff524b0bb483a545.js0 KB69 KB (76%)✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

D
HTTP Caching
Action
no-store (uncacheable)
FIX
no-store (uncacheable)
Info::
Cache-Control: no-store prevents all caching
Intentional for dynamic content, but increases server load for every page view.
Got: no-store
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

no-store

DirectiveValueMeaning
no-store—Never cache this response
B
Image Optimization
48 images, 0 KB saveable
REVIEW
48 images, 0 KB saveable
Info::
All images are well-optimized
48 images 350 KB
0 oversized -0 KB
24 legacy format
0 missing dimensions CLS risk
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
6 fonts (163 KB)
PASS
6 fonts (163 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

163 KB total

Render-blocking

0

of 6

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s FCP 3.6 s LCP 7.1 shttps://www.notion.com/front-static/fonts/NotionInter-Regular.woff2NotionInter-Regular.woff2 https://www.notion.com/front-static/fonts/NotionInter-Regular.woff2 — 22.3 KiB — 0 ms — font-display: swaphttps://www.notion.com/front-static/fonts/NotionInter-Medium.woff2NotionInter-Medium.woff2 https://www.notion.com/front-static/fonts/NotionInter-Medium.woff2 — 23.1 KiB — 0 ms — font-display: swaphttps://www.notion.com/front-static/fonts/NotionInter-SemiBold.woff2NotionInter-SemiBold.woff2 https://www.notion.com/front-static/fonts/NotionInter-SemiBold.woff2 — 23.5 KiB — 0 ms — font-display: swaphttps://www.notion.com/front-static/fonts/NotionInter-Bold.woff2NotionInter-Bold.woff2 https://www.notion.com/front-static/fonts/NotionInter-Bold.woff2 — 23.3 KiB — 0 ms — font-display: swaphttps://www.notion.com/_next/static/media/LyonText-Regular-Web.d7bfb4be.woff2LyonText-Regular-Web.d7... https://www.notion.com/_next/static/media/LyonText-Regular-Web.d7bfb4be.woff2 — 52.7 KiB — 0 ms — font-display: swaphttps://www.notion.com/_next/static/media/NotionInter-Regular-i18n.4c3206e4.woff2NotionInter-Regular-i18... https://www.notion.com/_next/static/media/NotionInter-Regular-i18n.4c3206e4.woff2 — 18.3 KiB — 0 ms — font-display: swap
NotionInter-Regular.woff2 woff2 swap
Size 22 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
NotionInter-Medium.woff2 woff2 swap
Size 23 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
NotionInter-SemiBold.woff2 woff2 swap
Size 23 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
NotionInter-Bold.woff2 woff2 swap
Size 23 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
LyonText-Regular-Web.d7... woff2 swap
Size 53 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
NotionInter-Regular-i18... woff2 swap
Size 18 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
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 Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
54 hints, 0 missing preconnects
PASS
54 hints, 0 missing preconnects
Info::
Page uses 54 resource hint(s)

Current Resource Hints

preconnect
3
preload
+20
30
dns-prefetch
—
prefetch
+11
21

54 resource hints configured

Network Waterfall
184 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 18939ms · 935KB · $251/mo
www.notion.com
Other
Costly
Execution 8260ms
Transfer 192 KB
Unused 89%
Monthly Cost $110/mo
www.notion.com
Other
Costly
Execution 3062ms
Transfer 46 KB
Monthly Cost $41/mo
www.notion.com
Other
Costly
Execution 2455ms
Transfer 58 KB
Monthly Cost $33/mo
Unattributable
Other
Costly
Execution 2311ms
Transfer 0 KB
Monthly Cost $31/mo
www.notion.com
Other
Costly
Execution 659ms
Transfer 252 KB
Unused 32%
Monthly Cost $9/mo
www.notion.com
Other
Costly
Execution 383ms
Transfer 0 KB
Monthly Cost $5/mo
transcend-cdn.com
Other
Costly
Execution 370ms
Transfer 99 KB
Unused 39%
Monthly Cost $5/mo
transcend-cdn.com
Other
Costly
Execution 264ms
Transfer 54 KB
Monthly Cost $4/mo
www.notion.com
Other
Costly
Execution 245ms
Transfer 41 KB
Monthly Cost $3/mo
www.notion.com
Other
Costly
Execution 222ms
Transfer 1 KB
Monthly Cost $3/mo
www.notion.com
Other
Optional
Execution 191ms
Transfer 15 KB
Monthly Cost $3/mo
www.notion.com
Other
Optional
Execution 176ms
Transfer 36 KB
Unused 80%
Monthly Cost $2/mo
www.notion.com
Other
Optional
Execution 106ms
Transfer 24 KB
Monthly Cost $1/mo
adora-cdn.com
Other
Optional
Execution 68ms
Transfer 47 KB
Unused 79%
Monthly Cost $1/mo
www.notion.com
Other
Optional
Execution 64ms
Transfer 19 KB
Monthly Cost $1/mo
www.notion.com
Other
Optional
Execution 54ms
Transfer 29 KB
Monthly Cost $1/mo
www.notion.com
Other
Optional
Execution 50ms
Transfer 24 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • www.notion.com adds 8260ms and costs ~$110/month
  • www.notion.com adds 3062ms and costs ~$41/month
  • www.notion.com adds 2455ms and costs ~$33/month
  • Unattributable adds 2311ms and costs ~$31/month
  • www.notion.com adds 659ms and costs ~$9/month
  • www.notion.com adds 383ms and costs ~$5/month
  • transcend-cdn.com adds 370ms and costs ~$5/month
  • transcend-cdn.com adds 264ms and costs ~$4/month
  • www.notion.com adds 245ms and costs ~$3/month
  • www.notion.com adds 222ms and costs ~$3/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

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 8260ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

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.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

www.notion.com takes 3062ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

www.notion.com takes 2455ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Unattributable takes 2311ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

www.notion.com takes 659ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

www.notion.com takes 383ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

transcend-cdn.com takes 370ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

transcend-cdn.com takes 264ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

www.notion.com takes 245ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

www.notion.com takes 222ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

80% of www.notion.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

79% of adora-cdn.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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