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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
63
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.
96
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.

1.21 s

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

1.98 s

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

431 ms

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

0.004

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

2.56 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.

4.96 s

Page Load Progression

969 ms
1.9 s
2.9 s
3.9 s
4.8 s
5.8 s
6.8 s
7.8 s
Checks
14
5 PASS 2 REVIEW 5 FIX
F
Page Weight Budget
Action
3.6 MB transferred, 193 requests
FIX
3.6 MB transferred, 193 requests
Warning::
Page weighs 9.7 MB (3.6 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::
193 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.76 g CO2 per page load
3.6 MB / 2.4 MB budget
3.6 MB transferred
193 requests
0.76 g CO2 per page load
JavaScript 1.2 MiB 35%
Other 943.4 KiB 26%
Images 500.6 KiB 14%
Other 461.0 KiB 12%
Other 171.8 KiB 5%
Fonts 163.2 KiB 4%
CSS 116.8 KiB 3%
HTML 58.3 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 (3.6 MiB of 3.6 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
3621ms total JS execution
FIX
3621ms total JS execution
Warning::
https://www.notion.com/_next/static/chunks/framewo...: 881ms CPU time
Warning::
https://www.notion.com/_next/static/chunks/sentry....: 692ms CPU time
Warning::
https://www.notion.com/: 649ms CPU time
Warning::
Unattributable: 634ms CPU time
Info::
https://www.notion.com/_next/static/chunks/pages/_...: 167ms CPU time
Warning::
Third-party scripts: 3621ms (100% of total)

Main Thread Breakdown

Script Evaluation 41% Other 27% Style & Layout 19% Script Parsing & Compilation 8%
ScriptTotalScriptingParse/CompileParty
https://www.notion.com/_next/static/chunks/framework-23933e8b27fffebb.js881ms656ms7ms3rd
https://www.notion.com/_next/static/chunks/sentry.next.be9c9dd35e340856.js692ms164ms46ms3rd
https://www.notion.com/649ms42ms1ms3rd
Unattributable634ms64ms0ms3rd
https://www.notion.com/_next/static/chunks/pages/_app-1ba900149c08adf4.js167ms114ms52ms3rd
https://transcend-cdn.com/cm/a36a42ad-3a71-444f-9e8a-b19950129dc6/ui.js115ms90ms24ms3rd
https://www.notion.com/_next/static/chunks/71564-8b3bdbd0a7387558.js112ms94ms1ms3rd
https://www.notion.com/_next/static/chunks/main-9070ba6adf5df692.js97ms85ms6ms3rd
https://www.notion.com/_next/static/chunks/69104.c88aab62f86e84a0.js95ms3ms4ms3rd
https://transcend-cdn.com/cm/a36a42ad-3a71-444f-9e8a-b19950129dc6/airgap.js68ms60ms6ms3rd

Showing top 10 of 12 scripts

F
JS Bundles
Action
87 scripts, 1.8 MB unused
FIX
87 scripts, 1.8 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: 1.8 MB
1845 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.js0 KB113 KB (99%)✓3rd
https://www.notion.com/_next/static/chunks/17270-bf2dfc8416258a85.js41 KB113 KB (99%)✓3rd
https://www.notion.com/_next/static/chunks/95503-1aa967ee7bce5b4e.js67 KB99 KB (57%)✓3rd
https://www.notion.com/_next/static/chunks/95503-1aa967ee7bce5b4e.js0 KB99 KB (57%)✓3rd
https://www.notion.com/_next/static/chunks/pages/_app-1ba900149c08adf4.js252 KB80 KB (32%)✓3rd
https://accounts.google.com/gsi/client93 KB70 KB (76%)✓3rd
https://www.notion.com/_next/static/chunks/57222-f7dea7c609c3b5ed.js0 KB58 KB (67%)✓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
54 images, 0 KB saveable
REVIEW
54 images, 0 KB saveable
Info::
All images are well-optimized
54 images 501 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 500 ms 1.0 s 1.5 s 2.0 s FCP 1.2 s LCP 2.0 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
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
Network Waterfall
193 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 3621ms · 793KB · $48/mo
www.notion.com
Other
Costly
Execution 881ms
Transfer 46 KB
Monthly Cost $12/mo
www.notion.com
Other
Costly
Execution 692ms
Transfer 192 KB
Unused 89%
Monthly Cost $9/mo
www.notion.com
Other
Costly
Execution 649ms
Transfer 58 KB
Monthly Cost $9/mo
Unattributable
Other
Costly
Execution 634ms
Transfer 0 KB
Monthly Cost $8/mo
www.notion.com
Other
Optional
Execution 167ms
Transfer 252 KB
Unused 32%
Monthly Cost $2/mo
transcend-cdn.com
Other
Optional
Execution 115ms
Transfer 99 KB
Unused 39%
Monthly Cost $2/mo
www.notion.com
Other
Optional
Execution 112ms
Transfer 0 KB
Unused 84%
Monthly Cost $1/mo
www.notion.com
Other
Optional
Execution 97ms
Transfer 41 KB
Monthly Cost $1/mo
www.notion.com
Other
Optional
Execution 95ms
Transfer 15 KB
Monthly Cost $1/mo
transcend-cdn.com
Other
Optional
Execution 68ms
Transfer 54 KB
Monthly Cost $1/mo
www.notion.com
Other
Optional
Execution 57ms
Transfer 1 KB
Monthly Cost $1/mo
www.notion.com
Other
Optional
Execution 55ms
Transfer 36 KB
Unused 80%
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • www.notion.com adds 881ms and costs ~$12/month
  • www.notion.com adds 692ms and costs ~$9/month
  • www.notion.com adds 649ms and costs ~$9/month
  • Unattributable adds 634ms and costs ~$8/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 881ms 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 692ms 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 649ms 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 634ms 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

84% 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

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

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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