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https://www.stripe.dev

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
85
GRADE
B
FIX
2
REVIEW
2
PASS
8
INFO
2

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

Mobile Desktop
98
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.

584 ms

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

831 ms

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

1 ms

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

0.002

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

1.31 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.

859 ms

Page Load Progression

438 ms
876 ms
1.3 s
1.8 s
2.2 s
2.6 s
3.1 s
3.5 s
Checks
14
8 PASS 2 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 (366.4 KiB of 366.6 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
JS Execution Cost
Action
2258ms total JS execution
FIX
2258ms total JS execution
Warning::
https://stripe.dev/_next/static/chunks/0uvx_1ip89~...: 984ms CPU time
Warning::
https://stripe.dev/: 684ms CPU time
Warning::
https://stripe.dev/_next/static/chunks/0wuvx6-x2fq...: 298ms CPU time
Info::
Unattributable: 111ms CPU time
Info::
https://stripe.dev/_next/static/chunks/0t9t-9dsl2d...: 111ms CPU time
Warning::
Third-party scripts: 2258ms (100% of total)

Main Thread Breakdown

Script Evaluation 34% Other 31% Style & Layout 26% Rendering 7%
ScriptTotalScriptingParse/CompileParty
https://stripe.dev/_next/static/chunks/0uvx_1ip89~4x.js984ms537ms10ms3rd
https://stripe.dev/684ms2ms0ms3rd
https://stripe.dev/_next/static/chunks/0wuvx6-x2fqhp.js298ms30ms1ms3rd
Unattributable111ms3ms0ms3rd
https://stripe.dev/_next/static/chunks/0t9t-9dsl2dxg.js111ms110ms1ms3rd
https://stripe.dev/_next/static/chunks/0b29c3sj~k-mz.js70ms53ms5ms3rd
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
367 KB transferred, 33 requests
PASS
367 KB transferred, 33 requests
Info::
Page weighs 1.1 MB (367 KB transferred)
Info::
33 HTTP requests
Info::
Estimated 0.08 g CO2 per page load
367 KB / 2.4 MB budget
367 KB transferred
33 requests
0.08 g CO2 per page load
JavaScript 216.4 KiB 59%
Fonts 84.7 KiB 23%
Other 27.5 KiB 8%
CSS 18.6 KiB 5%
HTML 14.4 KiB 4%
Other 4.9 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 500 ms 1.0 s FCP 584 ms LCP 831 mshttps://stripe.dev/fonts/SohneMono-Buch.woff2SohneMono-Buch.woff2 https://stripe.dev/fonts/SohneMono-Buch.woff2 — 27.0 KiB — 0 ms — font-display: swaphttps://stripe.dev/fonts/Sohne.woff2Sohne.woff2 https://stripe.dev/fonts/Sohne.woff2 — 57.7 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+
JS Bundles
19 scripts, 46 KB unused
PASS
19 scripts, 46 KB unused
Warning::
https://stripe.dev/_next/static/chunks/0b29c3sj~k-...: 23 KB unused (45%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://stripe.dev/_next/static/chunks/0uvx_1ip89~...: 23 KB unused (35%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 46 KB
46 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://stripe.dev/_next/static/chunks/0b29c3sj~k-mz.js53 KB23 KB (45%)✓3rd
https://stripe.dev/_next/static/chunks/0uvx_1ip89~4x.js67 KB23 KB (35%)✓3rd
https://stripe.dev/_next/static/chunks/0wuvx6-x2fqhp.js13 KB—✓3rd
https://stripe.dev/_next/static/8U4NAR3mngFkQBs4XFevr/_buildManifest.js1 KB—✓3rd
https://stripe.dev/_next/static/chunks/turbopack-0hiarq.gu0mr6.js5 KB—✓3rd
https://stripe.dev/_next/static/chunks/037j~mf4bj1lq.js5 KB—✓3rd
https://stripe.dev/_next/static/chunks/0t9t-9dsl2dxg.js7 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/0v61370_xgaw..js14 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

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
33 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 2258ms · 154KB · €25/mo
stripe.dev
Other
Costly
Execution 984ms
Transfer 67 KB
Unused 35%
Monthly Cost €11/mo
stripe.dev
Other
Costly
Execution 684ms
Transfer 14 KB
Monthly Cost €7/mo
stripe.dev
Other
Costly
Execution 298ms
Transfer 13 KB
Monthly Cost €3/mo
Unattributable
Other
Optional
Execution 111ms
Transfer 0 KB
Monthly Cost €1/mo
stripe.dev
Other
Optional
Execution 111ms
Transfer 7 KB
Monthly Cost €1/mo
stripe.dev
Other
Optional
Execution 70ms
Transfer 53 KB
Unused 45%
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • stripe.dev adds 984ms and costs ~€11/month
  • stripe.dev adds 684ms and costs ~€7/month
  • stripe.dev adds 298ms 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 984ms 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 684ms 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 298ms 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

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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