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https://www.replit.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
72
GRADE
C
FIX
5
REVIEW
1
PASS
6
INFO
2

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

Mobile Desktop
41
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
87
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
73
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.

1.02 s

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

4.47 s

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

1.26 s

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

0.026

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

2.54 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.

9.83 s

Page Load Progression

1.2 s
2.4 s
3.6 s
4.8 s
6.0 s
7.2 s
8.4 s
9.6 s
Checks
14
6 PASS 1 REVIEW 5 FIX
F
Page Weight Budget
Action
5.8 MB transferred, 256 requests
FIX
5.8 MB transferred, 256 requests
Critical::
Page weighs 20.5 MB (5.8 MB transferred)
Warning::
JavaScript is 5.1 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 5.1 MB
Info::
Fonts are 425 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 425 KB
Warning::
256 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 1.2 g CO2 per page load
5.8 MB / 2.4 MB budget
5.8 MB transferred
256 requests
1.2 g CO2 per page load
JavaScript 5.1 MiB 88%
Fonts 425.1 KiB 7%
CSS 166.3 KiB 3%
HTML 112.0 KiB 2%
Images 15.4 KiB 0%
Other 12.9 KiB 0%
Other 5.2 KiB 0%
Other 4.9 KiB 0%
Other 870 B 0%
Other 301 B 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

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 (5.8 MiB of 5.8 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
4290ms total JS execution
FIX
4290ms total JS execution
Warning::
https://cdn.replit.com/_next/static/chunks/0i8wy8t...: 916ms CPU time
Warning::
https://replit.com/: 895ms CPU time
Warning::
https://cdn.replit.com/_next/static/chunks/01eyejq...: 536ms CPU time
Warning::
https://cdn.replit.com/_next/static/chunks/0to4sxe...: 455ms CPU time
Warning::
Unattributable: 357ms CPU time
Warning::
Third-party scripts: 4290ms (100% of total)

Main Thread Breakdown

Script Evaluation 56% Style & Layout 15% Other 12% Script Parsing & Compilation 10%
ScriptTotalScriptingParse/CompileParty
https://cdn.replit.com/_next/static/chunks/0i8wy8tbht2ow.js916ms659ms4ms3rd
https://replit.com/895ms6ms1ms3rd
https://cdn.replit.com/_next/static/chunks/01eyejqjhinfj.js536ms481ms5ms3rd
https://cdn.replit.com/_next/static/chunks/0to4sxecg1htq.js455ms387ms36ms3rd
Unattributable357ms41ms0ms3rd
https://cdn.replit.com/_next/static/chunks/turbopack-0ysfnu9esvk6v.js232ms226ms0ms3rd
https://cdn.replit.com/_next/static/chunks/turbopack-0ejfz3q42gqc6.js203ms201ms1ms3rd
https://www.googletagmanager.com/gtag/js?id=G-MPJY3F1YEL&cx=c&_slc=1193ms138ms16ms3rd
https://js.stripe.com/acacia/stripe.js113ms80ms33ms3rd
https://www.gstatic.com/recaptcha/releases/kUYUkUlSyqkjTSMaN2w3RaOh/recaptcha__en.js87ms51ms29ms3rd

Showing top 10 of 15 scripts

F
JS Bundles
Action
187 scripts, 1.9 MB unused
FIX
187 scripts, 1.9 MB unused
Warning::
https://www.gstatic.com/recaptcha/releases/kUYUkUl...: 153 KB unused (45%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.gstatic.com/recaptcha/releases/kUYUkUl...: 153 KB unused (45%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.gstatic.com/recaptcha/releases/kUYUkUl...: 153 KB unused (45%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://js.stripe.com/acacia/stripe.js: 141 KB unused (64%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.replit.com/_next/static/chunks/0to4sxe...: 110 KB unused (90%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.9 MB
1916 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.gstatic.com/recaptcha/releases/kUYUkUlSyqkjTSMaN2w3RaOh/recaptcha__en.js0 KB153 KB (45%)✓3rd
https://www.gstatic.com/recaptcha/releases/kUYUkUlSyqkjTSMaN2w3RaOh/recaptcha__en.js363 KB153 KB (45%)✓3rd
https://www.gstatic.com/recaptcha/releases/kUYUkUlSyqkjTSMaN2w3RaOh/recaptcha__en.js363 KB153 KB (45%)✓3rd
https://js.stripe.com/acacia/stripe.js220 KB141 KB (64%)✓3rd
https://cdn.replit.com/_next/static/chunks/0to4sxecg1htq.js123 KB110 KB (90%)✓3rd
https://accounts.google.com/gsi/client93 KB69 KB (75%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-MPJY3F1YEL&cx=c&_slc=1172 KB68 KB (39%)✓3rd
https://www.google-analytics.com/gtm/js?id=OPT-TG46GJV&cid=679963144.1775593738108 KB68 KB (62%)✓3rd
https://cdn.replit.com/_next/static/chunks/0lwq8bzhc8c1k.js91 KB67 KB (74%)✓3rd
https://cdn.replit.com/_next/static/chunks/0~l37myivhd-2.js75 KB66 KB (89%)✓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
10 images, 0 KB saveable
REVIEW
10 images, 0 KB saveable
Info::
All images are well-optimized
10 images 15 KB
0 oversized -0 KB
6 legacy format
0 missing dimensions CLS risk
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
9 fonts (425 KB)
PASS
9 fonts (425 KB)
Info::
9 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

9

425 KB total

Render-blocking

0

of 9

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 1.0 s LCP 4.5 shttps://replit.com/public/fonts/ibm-plex-sans-v8-latin-regular.woff2ibm-plex-sans-v8-latin-... https://replit.com/public/fonts/ibm-plex-sans-v8-latin-regular.woff2 — 17.6 KiB — 0 ms — font-display: swaphttps://replit.com/public/fonts/ibm-plex-sans-v8-latin-italic.woff2ibm-plex-sans-v8-latin-... https://replit.com/public/fonts/ibm-plex-sans-v8-latin-italic.woff2 — 19.2 KiB — 0 ms — font-display: swaphttps://replit.com/public/fonts/ibm-plex-sans-v8-latin-500.woff2ibm-plex-sans-v8-latin-... https://replit.com/public/fonts/ibm-plex-sans-v8-latin-500.woff2 — 18.5 KiB — 0 ms — font-display: swaphttps://replit.com/public/fonts/ibm-plex-sans-v8-latin-500italic.woff2ibm-plex-sans-v8-latin-... https://replit.com/public/fonts/ibm-plex-sans-v8-latin-500italic.woff2 — 20.1 KiB — 0 ms — font-display: swaphttps://replit.com/public/fonts/ibm-plex-sans-v8-latin-600.woff2ibm-plex-sans-v8-latin-... https://replit.com/public/fonts/ibm-plex-sans-v8-latin-600.woff2 — 18.7 KiB — 0 ms — font-display: swaphttps://replit.com/public/fonts/ibm-plex-sans-v8-latin-600italic.woff2ibm-plex-sans-v8-latin-... https://replit.com/public/fonts/ibm-plex-sans-v8-latin-600italic.woff2 — 19.7 KiB — 0 ms — font-display: swaphttps://replit.com/public/fonts/ABCDiatypePlusVariable-Regular.woff2ABCDiatypePlusVariable-... https://replit.com/public/fonts/ABCDiatypePlusVariable-Regular.woff2 — 225.6 KiB — 0 ms — font-display: swaphttps://replit.com/public/fonts/ABCDiatype-RegularPixelBeta.woff2ABCDiatype-RegularPixel... https://replit.com/public/fonts/ABCDiatype-RegularPixelBeta.woff2 — 51.8 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 33.9 KiB — 0 ms — font-display: swap
ibm-plex-sans-v8-latin-... woff2 swap
Size 18 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-sans-v8-latin-... woff2 swap
Size 19 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-sans-v8-latin-... woff2 swap
Size 18 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-sans-v8-latin-... woff2 swap
Size 20 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-sans-v8-latin-... woff2 swap
Size 19 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ibm-plex-sans-v8-latin-... woff2 swap
Size 20 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ABCDiatypePlusVariable-... woff2 swap
Size 226 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
ABCDiatype-RegularPixel... woff2 swap
Size 52 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 34 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 ~113 KB and ~226 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
256 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 4290ms · 1093KB · $57/mo
cdn.replit.com
Other
Costly
Execution 916ms
Transfer 43 KB
Monthly Cost $12/mo
replit.com
Other
Costly
Execution 895ms
Transfer 80 KB
Monthly Cost $12/mo
cdn.replit.com
Other
Costly
Execution 536ms
Transfer 54 KB
Unused 52%
Monthly Cost $7/mo
cdn.replit.com
Other
Costly
Execution 455ms
Transfer 123 KB
Unused 90%
Monthly Cost $6/mo
Unattributable
Other
Costly
Execution 357ms
Transfer 0 KB
Monthly Cost $5/mo
cdn.replit.com
Other
Costly
Execution 232ms
Transfer 6 KB
Monthly Cost $3/mo
cdn.replit.com
Other
Costly
Execution 203ms
Transfer 6 KB
Monthly Cost $3/mo
Google Tag Manager
Tag Manager
Optional
Execution 193ms
Transfer 172 KB
Unused 39%
Monthly Cost $3/mo
Stripe
Payment
Essential
Execution 113ms
Transfer 220 KB
Unused 64%
Monthly Cost $2/mo
www.gstatic.com
Other
Optional
Execution 87ms
Transfer 0 KB
Unused 45%
Monthly Cost $1/mo
cdn.replit.com
Other
Optional
Execution 72ms
Transfer 47 KB
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 66ms
Transfer 140 KB
Unused 37%
Monthly Cost $1/mo
Segment
Analytics
Optional
Execution 63ms
Transfer 9 KB
Monthly Cost $1/mo
js.hcaptcha.com
Other
Optional
Execution 51ms
Transfer 86 KB
Unused 40%
Monthly Cost $1/mo
Google Analytics
Analytics
Optional
Execution 50ms
Transfer 108 KB
Unused 62%
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • cdn.replit.com adds 916ms and costs ~$12/month
  • replit.com adds 895ms and costs ~$12/month
  • cdn.replit.com adds 536ms and costs ~$7/month
  • cdn.replit.com adds 455ms and costs ~$6/month
  • Unattributable adds 357ms and costs ~$5/month
  • cdn.replit.com adds 232ms and costs ~$3/month
  • cdn.replit.com adds 203ms 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

cdn.replit.com takes 916ms 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

replit.com takes 895ms 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

cdn.replit.com takes 536ms 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 cdn.replit.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

cdn.replit.com takes 455ms 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

90% of cdn.replit.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 357ms 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

cdn.replit.com takes 232ms 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

cdn.replit.com takes 203ms 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

64% of Stripe'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

62% of Google Analytics'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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