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https://www.superhuman.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
77
GRADE
C
FIX
4
REVIEW
2
PASS
6
INFO
2

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

Mobile Desktop
73
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
94
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.

1.27 s

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

3.88 s

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

41 ms

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.

1.91 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.

4.16 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
14
6 PASS 2 REVIEW 4 FIX
F
Page Weight Budget
Action
2.6 MB transferred, 79 requests
FIX
2.6 MB transferred, 79 requests
Warning::
Page weighs 5.6 MB (2.6 MB transferred)
Warning::
JavaScript is 1.0 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.0 MB
Info::
Fonts are 442 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 442 KB
Info::
79 HTTP requests
Info::
Estimated 0.54 g CO2 per page load
2.6 MB / 2.4 MB budget
2.6 MB transferred
79 requests
0.54 g CO2 per page load
JavaScript 1.0 MiB 39%
Images 834.0 KiB 32%
Fonts 442.1 KiB 17%
HTML 157.1 KiB 6%
Other 124.3 KiB 5%
CSS 38.2 KiB 1%
Other 4.2 KiB 0%
Other 1.5 KiB 0%
Other 1.2 KiB 0%
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

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

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 (2.6 MiB of 2.6 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
JS Bundles
Action
27 scripts, 302 KB unused
FIX
27 scripts, 302 KB unused
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-TNL...: 78 KB unused (52%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-6MW7...: 67 KB unused (38%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=AW-176...: 64 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://superhumanstatic.com/super-funnel/main/b/0...: 55 KB unused (63%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://transcend-cdn.com/cm/1c1f8e90-47d0-4bba-a1...: 37 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 302 KB
302 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtm.js?id=GTM-TNL2F7CJ151 KB78 KB (52%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-6MW74FKGFX&cx=c&gtm=4e6460177 KB67 KB (38%)✓3rd
https://www.googletagmanager.com/gtag/js?id=AW-17616940428&cx=c&gtm=4e6460144 KB64 KB (44%)✓3rd
https://superhumanstatic.com/super-funnel/main/b/0-15521/_next/static/chunks/framework-06defa391493af96.js88 KB55 KB (63%)✓3rd
https://transcend-cdn.com/cm/1c1f8e90-47d0-4bba-a1a2-472d59b002a2/ui.js93 KB37 KB (40%)✓3rd
https://superhumanstatic.com/super-funnel/main/b/0-15521/_next/static/chunks/669-8d9692bf6be3aa29.js10 KB—✓3rd
https://superhumanstatic.com/super-funnel/main/b/0-15521/_next/static/chunks/71-66029a225f8fb6fe.js4 KB—✓3rd
https://superhumanstatic.com/super-funnel/main/b/0-15521/_next/static/chunks/516-c6b87318c4dfde27.js5 KB—✓3rd
https://superhumanstatic.com/super-funnel/main/b/0-15521/_next/static/chunks/530.98d153af388991d0.js1 KB—✓3rd
https://superhumanstatic.com/super-funnel/main/b/0-15521/_next/static/chunks/bab35d53-893fddd1ed83b16f.js11 KB—✓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

F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

B
Image Optimization
17 images, 0 KB saveable
REVIEW
17 images, 0 KB saveable
Info::
All images are well-optimized
17 images 831 KB
0 oversized -0 KB
14 legacy format
0 missing dimensions CLS risk
C
JS Execution Cost
Action
1317ms total JS execution
REVIEW
1317ms total JS execution
Warning::
https://superhuman.com/: 478ms CPU time
Warning::
https://superhumanstatic.com/super-funnel/main/b/0...: 384ms CPU time
Warning::
Unattributable: 257ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-6MW7...: 76ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-TNL...: 62ms CPU time
Warning::
Third-party scripts: 1317ms (100% of total)

Main Thread Breakdown

Script Evaluation 38% Other 32% Style & Layout 14% Rendering 6% Script Parsing & Compilation 5%
ScriptTotalScriptingParse/CompileParty
https://superhuman.com/478ms6ms0ms3rd
https://superhumanstatic.com/super-funnel/main/b/0-15521/_next/static/chunks/framework-06defa391493af96.js384ms268ms13ms3rd
Unattributable257ms4ms0ms3rd
https://www.googletagmanager.com/gtag/js?id=G-6MW74FKGFX&cx=c&gtm=4e646076ms61ms10ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-TNL2F7CJ62ms48ms8ms3rd
https://transcend-cdn.com/cm/1c1f8e90-47d0-4bba-a1a2-472d59b002a2/ui.js60ms44ms8ms3rd
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
5 fonts (442 KB)
PASS
5 fonts (442 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

442 KB total

Render-blocking

0

of 5

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 FCP 1.3 s LCP 3.9 shttps://superhumanstatic.com/s/fonts/v1/SuperSans-VF-Upright.woff2SuperSans-VF-Upright.woff2 https://superhumanstatic.com/s/fonts/v1/SuperSans-VF-Upright.woff2 — 106.2 KiB — 0 ms — font-display: swaphttps://superhumanstatic.com/s/fonts/v1/SuperSans-VF-Italic.woff2SuperSans-VF-Italic.woff2 https://superhumanstatic.com/s/fonts/v1/SuperSans-VF-Italic.woff2 — 118.2 KiB — 0 ms — font-display: swaphttps://superhumanstatic.com/s/fonts/v1/SuperSerif-VF-Upright.woff2SuperSerif-VF-Upright.w... https://superhumanstatic.com/s/fonts/v1/SuperSerif-VF-Upright.woff2 — 74.0 KiB — 0 ms — font-display: swaphttps://superhumanstatic.com/s/fonts/v1/SuperSerif-VF-Italic.woff2SuperSerif-VF-Italic.woff2 https://superhumanstatic.com/s/fonts/v1/SuperSerif-VF-Italic.woff2 — 81.0 KiB — 0 ms — font-display: swaphttps://superhumanstatic.com/s/fonts/v1/SuperSansMono-VF.woff2SuperSansMono-VF.woff2 https://superhumanstatic.com/s/fonts/v1/SuperSansMono-VF.woff2 — 62.7 KiB — 0 ms — font-display: swap
SuperSans-VF-Upright.woff2 woff2 swap
Size 106 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
SuperSans-VF-Italic.woff2 woff2 swap
Size 118 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
SuperSerif-VF-Upright.w... woff2 swap
Size 74 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
SuperSerif-VF-Italic.woff2 woff2 swap
Size 81 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
SuperSansMono-VF.woff2 woff2 swap
Size 63 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)

Fixing the unchecked items could save ~112 KB and ~224 ms

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
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
79 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 1317ms · 665KB · €14/mo
superhuman.com
Other
Costly
Execution 478ms
Transfer 157 KB
Monthly Cost €5/mo
superhumanstatic.com
Other
Costly
Execution 384ms
Transfer 88 KB
Unused 63%
Monthly Cost €4/mo
Unattributable
Other
Costly
Execution 257ms
Transfer 0 KB
Monthly Cost €3/mo
Google Tag Manager
Tag Manager
Optional
Execution 76ms
Transfer 177 KB
Unused 38%
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 62ms
Transfer 151 KB
Unused 52%
Monthly Cost €1/mo
transcend-cdn.com
Other
Optional
Execution 60ms
Transfer 93 KB
Unused 40%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • superhuman.com adds 478ms and costs ~€5/month
  • superhumanstatic.com adds 384ms and costs ~€4/month
  • Unattributable adds 257ms 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

superhuman.com takes 478ms 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

superhumanstatic.com takes 384ms 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

63% of superhumanstatic.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

Unattributable takes 257ms 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

52% of Google Tag Manager'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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