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https://www.stripe.dev

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
85
GRADE
B
FIX
2
REVIEW
3
PASS
9
INFO
2

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

Mobile Desktop
78
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
96
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.
91
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.

1.83 s

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

3.45 s

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

475 ms

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

0.001

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

2.06 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.

4.93 s

Page Load Progression

403 ms
805 ms
1.2 s
1.6 s
2.0 s
2.4 s
2.8 s
3.2 s
Checks
16
9 PASS 3 REVIEW 2 FIX
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 (638.0 KiB of 638.2 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
5703ms total JS execution
FIX
5703ms total JS execution
Warning::
https://stripe.dev/_next/static/chunks/0uvx_1ip89~...: 2314ms CPU time
Warning::
https://stripe.dev/_next/static/chunks/0wuvx6-x2fq...: 1601ms CPU time
Warning::
https://stripe.dev/: 827ms CPU time
Warning::
Unattributable: 292ms CPU time
Info::
https://stripe.dev/_next/static/chunks/0nd2wb02x-8...: 143ms CPU time
Warning::
Third-party scripts: 5703ms (100% of total)

Main Thread Breakdown

Other 45% Script Evaluation 32% Style & Layout 11% Rendering 7% Script Parsing & Compilation 4%
ScriptTotalScriptingParse/CompileParty
https://stripe.dev/_next/static/chunks/0uvx_1ip89~4x.js2314ms1155ms26ms3rd
https://stripe.dev/_next/static/chunks/0wuvx6-x2fqhp.js1601ms163ms5ms3rd
https://stripe.dev/827ms7ms1ms3rd
Unattributable292ms13ms0ms3rd
https://stripe.dev/_next/static/chunks/0nd2wb02x-834.js143ms15ms3ms3rd
https://stripe.dev/_next/static/chunks/turbopack-0hiarq.gu0mr6.js138ms135ms2ms3rd
https://stripe.dev/_next/static/chunks/0c.n5x18151dz.js130ms126ms4ms3rd
https://stripe.dev/_next/static/chunks/0t9t-9dsl2dxg.js113ms109ms4ms3rd
https://stripe.dev/_next/static/chunks/turbopack-0e9tu6_ctnf0t.js77ms75ms2ms3rd
https://stripe.dev/_next/static/chunks/0b29c3sj~k-mz.js68ms11ms20ms3rd
C
JS Bundles
Action
34 scripts, 227 KB unused
REVIEW
34 scripts, 227 KB unused
Warning::
https://stripe.dev/_next/static/chunks/04vp02y0.g7...: 69 KB unused (69%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://stripe.dev/_next/static/chunks/16cer0h2fdu...: 52 KB unused (99%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://stripe.dev/_next/static/chunks/02-c.cxhqmd...: 52 KB unused (99%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://stripe.dev/_next/static/chunks/0b29c3sj~k-...: 30 KB unused (58%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://stripe.dev/_next/static/chunks/0uvx_1ip89~...: 24 KB unused (37%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 227 KB
227 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://stripe.dev/_next/static/chunks/04vp02y0.g70m.js103 KB69 KB (69%)✓3rd
https://stripe.dev/_next/static/chunks/16cer0h2fduw2.js53 KB52 KB (99%)✓3rd
https://stripe.dev/_next/static/chunks/02-c.cxhqmdyv.js52 KB52 KB (99%)✓3rd
https://stripe.dev/_next/static/chunks/0b29c3sj~k-mz.js53 KB30 KB (58%)✓3rd
https://stripe.dev/_next/static/chunks/0uvx_1ip89~4x.js66 KB24 KB (37%)✓3rd
https://stripe.dev/_next/static/chunks/0wuvx6-x2fqhp.js13 KB—✓3rd
https://stripe.dev/_next/static/chunks/0m303arsat9gp.js0 KB—✓3rd
https://stripe.dev/_next/static/chunks/0nd2wb02x-834.js7 KB—✓3rd
https://stripe.dev/_next/static/chunks/0ldk-.d8ed8j6.js9 KB—✓3rd
https://stripe.dev/_next/static/chunks/037j~mf4bj1lq.js4 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

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
public, max-age=0, must-revalidate
REVIEW
public, max-age=0, must-revalidate
Info::
Cache-Control header is set
Got: public, max-age=0, must-revalidate
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

public, max-age=0, must-revalidate

DirectiveValueMeaning
public—Any cache may store this response
max-age0Cache for 0 seconds
must-revalidate—Must recheck with server after expiry
A+
Page Weight Budget
638 KB transferred, 48 requests
PASS
638 KB transferred, 48 requests
Info::
Page weighs 1.9 MB (638 KB transferred)
Info::
48 HTTP requests
Info::
Estimated 0.13 g CO2 per page load
638 KB / 2.4 MB budget
638 KB transferred
48 requests
0.13 g CO2 per page load
JavaScript 488.1 KiB 76%
Fonts 85.4 KiB 13%
Other 27.3 KiB 4%
CSS 18.7 KiB 3%
HTML 14.4 KiB 2%
Other 4.3 KiB 1%
0 2.4 MB 4.9 MB
Under budget
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+
Image Optimization
No images on this page
PASS
No images on this page
Info::
No images on this page
0 images 0 KB
0 oversized -0 KB
0 legacy format
0 missing dimensions CLS risk
A+
Font Loading
2 fonts (85 KB)
PASS
2 fonts (85 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

85 KB total

Render-blocking

0

of 2

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 FCP 1.8 s LCP 3.5 shttps://stripe.dev/fonts/SohneMono-Buch.woff2SohneMono-Buch.woff2 https://stripe.dev/fonts/SohneMono-Buch.woff2 — 27.1 KiB — 0 ms — font-display: swaphttps://stripe.dev/fonts/Sohne.woff2Sohne.woff2 https://stripe.dev/fonts/Sohne.woff2 — 58.3 KiB — 0 ms — font-display: swap
SohneMono-Buch.woff2 woff2 swap
Size 27 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Sohne.woff2 woff2 swap
Size 58 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
4 hints, 0 missing preconnects
PASS
4 hints, 0 missing preconnects
Info::
Page uses 4 resource hint(s)

Current Resource Hints

preconnect
—
preload
4
dns-prefetch
—
prefetch
—

4 resource hints configured

A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
Network Waterfall
48 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 5703ms · 178KB · €62/mo
stripe.dev
Other
Costly
Execution 2314ms
Transfer 66 KB
Unused 37%
Monthly Cost €25/mo
stripe.dev
Other
Costly
Execution 1601ms
Transfer 13 KB
Monthly Cost €17/mo
stripe.dev
Other
Costly
Execution 827ms
Transfer 14 KB
Monthly Cost €9/mo
Unattributable
Other
Costly
Execution 292ms
Transfer 0 KB
Monthly Cost €3/mo
stripe.dev
Other
Optional
Execution 143ms
Transfer 7 KB
Monthly Cost €2/mo
stripe.dev
Other
Optional
Execution 138ms
Transfer 5 KB
Monthly Cost €1/mo
stripe.dev
Other
Optional
Execution 130ms
Transfer 9 KB
Monthly Cost €1/mo
stripe.dev
Other
Optional
Execution 113ms
Transfer 7 KB
Monthly Cost €1/mo
stripe.dev
Other
Optional
Execution 77ms
Transfer 5 KB
Monthly Cost €1/mo
stripe.dev
Other
Optional
Execution 68ms
Transfer 53 KB
Unused 58%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • stripe.dev adds 2314ms and costs ~€25/month
  • stripe.dev adds 1601ms and costs ~€17/month
  • stripe.dev adds 827ms and costs ~€9/month
  • Unattributable adds 292ms 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

stripe.dev takes 2314ms 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

stripe.dev takes 1601ms 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

stripe.dev takes 827ms 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 292ms 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

58% of stripe.dev'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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